• Aerospace Engineering and Technology
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• v.11 no.2
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• pp.73-79
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• 2012

Because the contact time between satellite and ground station is very limited in LEO (Low Earth Orbit) satellite, all telemetry data generated on spacecraft bus are stored in a mass memory and downlinked to the ground together with real time data during the contact time. The mass memory is initialized in the first system initialization phase and the page status of each memory block is generated step by step. After the completion of the system initialization, the telemetry data are continuously stored and the stored data are played back to the ground by command. And the memory scrubbing is periodically performed for correction of single bit error which can be generated on harsh space environment. This paper introduces the mass memory operation method for telemetry processing of LEO satellite. It includes a general mass memory data structure, the methods of mass memory initialization, scrubbing, data storage and downlink, and mass memory management of primary and redundant mass memory.

• The KIPS Transactions:PartB
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• v.8B no.5
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• pp.469-476
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• 2001

As the service of information through web system increases in modern society, many questions and consultations are going on through Home page and E-mail in the hospital. But there are some burdens for the management and postponements for answering the questions. In this paper, we investigate the document classification methods as a primary research of the auto-answering system. On the basis of 1200 documents which are questions of patients, 66% are used for the learning documents and 34% for test documents. All of are also used for the document classification using NBC (Naive Bayes Classifier), common words and coefficient of correlation. As the result of the experiments, the two methods proposed in this paper, that is, common words and coefficient of correlation are higher as much as 3% and 5% respectively than the basic NBC methods. This result shows that the correlation between indexes and categories is more effective than the word frequency in the document classification.

• Information Systems Review
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• v.7 no.1
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• pp.81-96
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• 2005

Because the web sites are in common today, the access to the web for disabled people and old aging people, what we call accessibility, becomes more important. Even though efforts to reduce the informational gap resulted from the lack of the accessibility have been carried out, the studies in this field in Korea are not still in popular. In this study, previous research on the measurements for the accessibility is reviewed and then a new model measuring accessibility is suggested. To increase the validity of the measurement, both an automated tool and a manual test are employed. First we used the 'A-Prompt', one of the popular automated validation tools and analyzed web sources, and applied manual tests by HPR Screen Reader. With the error rates calculated, the accessibility of the government web sites between Korea and the United States was compared and finally the conclusions were drawn.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.40 no.6
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• pp.78-86
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• 2003

When we transformed from Monochrome-data to Color-data in text mode, we used hardware-method to design the circuit which is convertible in real time. We saved color information in every screens that can make screen in Color Palette ROM and it is also generated 8bit. lower 4bit assign foreground color and upper 4bit can design to have background color. We have Address Reduction ROM to remove repeated address and reduce volume of Color Palette ROM to 1/16. Besides, we have many D-FF to save address, data and page information temporarily after that, we have management process 8 times through counter in real time. Finally, we chose either foreground color or background color in multiplex and established color information was sended to the color video controller. Thus, you can use it as a good interface when yow transfer many control devices with Monochrome display (ex, LCD Monitor) into devices with Color display.

• Journal of Advanced Navigation Technology
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• v.14 no.5
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• pp.767-774
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• 2010

Due to advantages of NAND flash memory such as non-volatility, low access latency, low energy consumption, light weight, small size and shock resistance, it has become a better alternative over traditional magnetic disk drives, and has been widely used. Traditional DBMSs including mobile DBMSs may run on flash memory without any modification by using Flash Translation Layer (FTL), which emulates a random access block device to hide the characteristics of flash memory such as "erase-before-update". However, most existing FTLs are optimized for file systems, not for DBMSs, and traditional DBMSs are not aware of them. Also, traditional DBMSs do not consider the characteristics of flash memory. In this paper, we propose a flash-conscious storage system for DBMSs that utilizes flash memory as a main storage medium, and carefully put the characteristics of flash memory into considerations. The proposed flash-conscious storage system exploits log records to avoid costly update operations. It is shown that the proposed storage system outperforms the state.

• Journal of KIISE:Databases
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• v.27 no.1
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• pp.1-12
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• 2000

Many object oriented database systems manage object buffers to provide fast access to objects. Traditional buffer replacement algorithms based on fixed length pages simply assume that the cost incurred by operating a buffer is propertional to the number of buffer faults. However, this assumption no longer holds in an objects buffer where objects are of variable length and the cost of replacing an object varies for each object. In this paper, we propose a cost based replacement algorithm for object buffers. The proposed algorithm replaces the have minimum costs per unit time and unit space. The cost model extends the previous page based one to include the replacement costs and the sizes of objects. The performance tests show that proposed algorithm is almost always superior to the LRU-2 algorithm and in some cases is more than twice as fast. The idea of cost based replacement can be applied to any buffer management architectures that adopt earlier algorithms. It is especially useful in object oriented database systems where there is significant variation in replacement costs.

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.104-105
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• 1998

To minimize the Y2K (year 2000) date aware problem of medical devices, we are developing a database that keeps the data such as equipment type, specification, serial number, model number, acquisition date, vendor, manufacturer of the device as well as the names of departments that installed and that is currently responsible for the management of the medical device. The database also keeps the information as to whether the device awares the date, whether it is affected by the Y2K problem or not, how to solve the problem, reference home page address, and so on. The data was collected via internet search of the FDA web site and related of manufacturers homepages. To manage the Y2K problem effectively, the database should be updated regularly to include recent information.

• Korean Journal of Community Nutrition
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• v.17 no.4
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• pp.390-406
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• 2012

Childhood obesity has rapidly increased worldwide and is one of the most serious health problems in this age group. In order to prevent and manage childhood obesity, we developed a nutrition education website. The website consisted of three parts. The first part was made for self-assessment with regard to obesity index, dietary habits, food frequency, dietary attitude, nutrition knowledge, nutrient intake, energy expenditure, and the stage of behavioral change, and tailored messages and advice according to the assessment results. A total of 612 real-size food photos as well as a nutrient database of 3,346 foods and 541 dishes were created to help children estimate nutrient intakes accurately. In addition, an energy expenditure database of 156 activities for children was established to calculate calorie consumption. The second part was made for setting long-term and short-term goals and keeping track of the changes in energy intake and expenditure in one's own page. The third part was made for education. Various types of nutrition information were provided; texts, pictures, calculators and games. The readability and design of the website were evaluated by 46 obese children. Usefulness, design and readability of the website were found to be desirable for children. This website is expected to be used by an obese child alone or with parents or nutrition teachers in order to control body weight through healthy dietary habits and physical activities. In addition, a non-obese child can also use this website for maintaining healthy dietary habits and preventing obesity.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.12C
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• pp.1251-1264
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• 2002

Currently, audio streaming services such as on-demand service and live service support only a limited number of clients. They also suffer from a lack of stability and degradation of service quality due to their inefficient use of network resources. Futhermore, since the streaming services usually do not consider dynamic services, they are very inconvenience to use. In order to resolve these drawbacks, we propose a novel audio streaming system based on MPEG-2 AAC file format which are facilitated with the network bandwidths efficiently. The proposed system supports QoS for audio streaming as well as guarantees a stability while streaming service is undergoing. Moreover, the system provides a dynamic interface which enables us to use the streaming service more easily and to manage streaming servers with convenient manner. On the contrary, most of the current available static interface streaming services are mainly depending only on a single fixed web page between client and server, which in consequence lead us to use unflexible static service environment. Our implementation results show the proposed system improves the performance compared to those of the currently existing systems that use MP3 file format. It also provides some benefits such as a stability of service and a easy to management of streaming servers.

• Journal of the Korean Data and Information Science Society
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• v.22 no.2
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• pp.159-169
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• 2011

A department homepage contains various informations related with the department. So, a role of the department homepage is very important for both of students and applicants. For this reason, D university is evaluating the homepages of all departments in viewpoint of the construction, design, and contents of homepage. But the method of this homepage evaluation has some problems. Therefore, in this study, we propose a objective index for department homepage evaluation which can be applied to homepages of the other departments. Also we expect to provide an important information for the efficient homepage management by using the proposed index for homepage evaluation.