• Journal of KIISE:Databases
• /
• v.32 no.2
• /
• pp.151-160
• /
• 2005

As web pages are created, destroyed, and updated frequently, web databases should be updated to keep up-to-date web pages. In order to keep web databases fresh effectively, we need to understand the change of real web pages. Previous researches on the change of the web pages have directed their efforts on the contents modification of web pages only, and have not taken into account the factors of creation and destruction of web pages In their research. This paper investigates the web page changes, which include contents modification, page creation, and page destruction. We introduce three metrics, namely DR (Download Rate), MR (Modification Rate), and CAV (Coefficient of Age Variation) to represent the change of the web pages. We have monitored three million web pages collected from the famous and random sites every other day for one hundred days. With the Download Rate and the Modification Rate, we learned that the download success and the modification depends on the past change of them, and proposes two estimation formulae that predict the download success and modification. With the Coefficient of Age Variation, we show how web pages do not change periodically.

• Design Convergence Study
• /
• v.14 no.2
• /
• pp.151-168
• /
• 2015

As the market of music download stores moved into the mobile epoch the market was growing explosively. Recently, the digital music market tends to move from the mp3 download market to streaming service and the users can use the service on their mobile devices without reference to any inconvenient download and limited storage capacity. It was found that they mainly use the recommendation music playlist, instant player, main player and sharing of the functions of the streaming service from the user behavior research. This is noticeable features that set apart from the mp3 download service. However, the interface design of the streaming app followed the previous service and it needs the optimization of its UI design. In this study, the usability of high ranked three mobile streaming apps was evaluated. The result of the test was that Naver music and Bugs had high scores overall in four sections of the streaming service features. On the other hand, the Melon had primarily high score in color application on the service. The aim of this study is to suggest the direction of the UI design of music streaming service through the understanding of essence of streaming service and evaluation the usability test.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.8 no.1
• /
• pp.1-9
• /
• 2013

Performance of smart phones has increased to conduct simple PC functions that has become essential to modern people. With the development of smart phones, not only limited inner sensors but various sensors can be connected through USB. However, there is problem that app needs to downloaded when using each sensor. In this paper, a smart phone unified app structure for USB sensor Plug&Play is presented. The structure was designed to download web pages to use various sensors in one app. Unified app communicated with the platform through ADK accessory protocol and implements structure of delivering sensor ID to the web server and downloading device driver, web page. By measurement test, it was confirmed that download time of web page in unified app was 10 times faster than original download time of original app. By managing various sensors by one app, the app is searched every time the sensor changes in which there is no need for downloading several apps.

• 한국전산유체공학회:학술대회논문집
• /
• 2009.04a
• /
• pp.43-50
• /
• 2009

In order to reduce the download around Smart UAV(SUAV) at hovering and transition mode, flow control using synthetic jet has been performed. Many of the complex tilt rotor flow features are captured including wing leading and trailing edge separation, and the large region of separated flow beneath the wing. First, in order to control the trailing edge separation, synthetic jet is located at 30, 95% of flap chord length. The flow control using synthetic jet on flap shows that stall characteristics depending on several mode can be improved through separation vortices resizing. Also, a flap jet and a 0.01c jet which control the separation efficiently are applied at the same time at each test case because controlling the leading edge separation is essential for download reduction. As a result, time averaged download is reduced about 18% comparing with no control case at hovering mode and 48% at transition mode. These research results show that if flow control using leading edge jet and trailing edge jet is used effectively to the SUAV in overall flight mode, flight performance and stability can be improved.

• Journal of Internet Computing and Services
• /
• v.18 no.2
• /
• pp.13-20
• /
• 2017

Recently, researches to adopt Content-centric network (CCN), which is one of the promising technologies for replacing TCP/IP-based networks, to wireless networks has actively performed. However, because of erroneous and unreliable channel characteristics, there are many problems to be resolved to adopt CCN to wireless networks. This paper proposes a method to reduce content download time because nodes possess only parts of content chunks. The proposed method enables a node having parts of content chunks to request the rest of parts of content chunks to a provider before a Consumer requests the content. As a consequence, the content download time is reduced.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.36 no.3B
• /
• pp.260-267
• /
• 2011

Wireless Local Area Network (WLAN) is recently become popular on the internet since we can download and transfer mass data through it. However, transferring data with distances over 100m often causes some troubles. When downloading mass data from moving vehicles such as cars, jeeps, tanks, etc., if the download process from the first AP (Access Point) is not completed then we have to re-start this process from the second AP (from 0%). Therefore, the question is how to maintain the data we have received from the first AP, and then continuously download remaining data from the next APs in a battlefield environment. In this paper, we propose an effective method for receiving mass data separately from the mobile receive nodes in a Delay Tolerant Network (DTN). We carried on an experiment and evaluation by simulation; these simulation results are provided to show the proposed information delivery scheme performance.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.66 no.12
• /
• pp.1792-1798
• /
• 2017

Event Data Recorder(Car Black-Box) with WiFi dongle have been released, and the platform of the majority is the Linux platform. This is because the platform development is possible in little investment cost by reducing the source licensing costs by taking advantage of the open source. But utilizing Linux platform has the limitations of boot-up time and consuming processing power due to the limitation of battery capacity, to be cost-competitive to minimize the use of memory. In this paper, the real-time operating system(RTOS) is utilized to optimize these portions. MP4 encoder and Muxer are developed to be about ten seconds boot up and minimized memory. It has the advantages of operating at lower power consumption than the Linux utilizing WiFi dongle. Utilizing a WiFi dongle is to provide a progressive download feature on smart phones to lower product prices. But RTOS has the weakness in WiFi. Porting TCP /IP, Web and DHCP server and combination with the USB OTG Host interface by implementing the protocol stack are developed for WiFi. And also SPI NOR flash memory is utilized for faster boot time and cost reductions, low processing power to be consume. As the results, the developed proved the 10 seconds booting time, 24 frame rate/sec. and 10% lower power consumption.

• Journal of Internet Computing and Services
• /
• v.7 no.2
• /
• pp.121-136
• /
• 2006

Software architecture and protocols to be maintained between components for the reconfigurable SDR system is analyzed and suggest system design idea for the implementation of software. To do this, related surveys are reviews and set up the system model with the structure of embedded system. SDR system architecture is suggested with five layered structure, consisted with hardware, operating system, middle-ware, service objects and application layer. SDR system is designed to be work on the basis of Linux operating system, and aimed to be scalable and reconfigurable. It is introduced the design result of software protocol and state transition diagram for the implementations of software download function which is the most important feature in SDR.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.21 no.5
• /
• pp.161-166
• /
• 2021

When testing various images outdoors with an infrared imaging system, it is necessary to save the tested images for comparison. In addition, after the test, it should be possible to easily connect to the PC and download the stored data. With the recent development of the memory system, it is possible to design an infrared image storage board for an outdoor test by using the eMMC memory that can be easily used in the form of an on board. In this paper, we describe the design of a portable image storage board that can easily store and download infrared images, and describe the GUI program that can connect to a PC and download the stored images.

• Proceedings of the IEEK Conference
• /
• 2005.11a
• /
• pp.1161-1164
• /
• 2005

In this paper, we proposed the technique to estimate the life cycle of Internet content services based on the logistic regression model. In this paper, to define parameters of Internet contents estimating life cycle by logistic regression model, we used market size, traffic amount, page view and session-visit number as the parameters of Internet contents estimating life cycle by logistic regression model. In this paper, to compare the performance of our proposed scheme, we estimated life cycle for the download services of bell sound & character contents in mobile network. As a result, using our proposed logistic regression, we were able to estimate exactly the life cycle of the download services of bell sound & character contents.