• Journal of the HCI Society of Korea
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• v.3 no.1
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• pp.49-56
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• 2008

Most recent mobile devices can store a massive amount of images. However, the typical user interface of mobile devices, such as a small-size 2D display and discrete-input buttons, make the browsing and manipulation of images cumbersome and time-consuming. As an alternative, we adopt motion-based interaction along with a 3D layout of images, expecting such an intuitive and natural interaction may facilitate the tasks. We designed and implemented a motion-based interaction scheme for image browsing using an ultra mobile PC, and evaluated and compared its usability to that of the traditional button-based interaction. The effects of data layouts (tiled and fisheye cylindrical layouts) were also investigated to see whether they can enhance the effectiveness of the motion based interaction.

• The KIPS Transactions:PartC
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• v.17C no.2
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• pp.159-164
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• 2010

The data wiping is a technique which perfectly deletes data in a storage to prevent data recovery. Currently, management of stored data is important because of increasing an accident of personal information leakage. Especially, if you need to discard data contained personal information, using a wiping tool which permanently deletes data to prevent unnecessary personal information leakage. The data wiping is also used for data security and privacy protection. However the data wiping can be used intentionally destruction of evidence. This intentionally destruction of evidence is important clues of forensic investigation. This paper demonstrates the methods for detecting the usage of wiping tools in digital forensic investigation.

• Journal of KIISE:Databases
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• v.35 no.5
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• pp.400-410
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• 2008

Flash memory has been widely used in mobile devices, such as mobile phone and digital camera. Recently flash SSD(Solid State Disk), having same interface of the disk drive, is replacing the hard disk of some laptop computers. However, flash memory still cannot be considered as the storage of database systems. The FTL(Flash Translation Layer) of commercial flash SSD, making flash memory operate exactly same as a hard disk, shows poor performance on the workload of databases with many random overwrites. Recently In-Page Logging(IPL) approach was proposed to solve this problem. In this paper, we implement IPL approach on SQLite, a popular open source embedded DBMS, and evaluate its performance. It improves the performance by up to 30 factors for update queries.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.685-688
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• 2006

A single-phase uninterruptible power supply system suitable for a SMES unit is proposed to achieve a simple circuit configuration and higher system reliability. It reduces the number of switching devices by applying a common-arm scheme. Operational principles to normal, stored-energy, and bypass mode are discussed in detail. Eliminating some of the switches or substituting passive components for active switches generally increases the sophistication and reduces degree of freedom in control strategy. However, the high-performance digital controller ran execute the complicated control task with no additional cost. The validity of the proposed UPS system will be verified by a computer-aided simulation.

• Journal of Digital Contents Society
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• v.18 no.1
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• pp.149-158
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• 2017

Big data have been presenting us with exciting opportunities and challenges in economic development. For instance, in the agriculture sector, mixing up of various agricultural data (e.g., weather data, soil data, etc.), and subsequently analyzing these data deliver valuable and helpful information to farmers and agribusinesses. However, massive data in agriculture are generated in every minute through multiple kinds of devices and services such as sensors and agricultural web markets. It leads to the challenges of big data problem including data collection, data storage, and data analysis. Although some systems have been proposed to address this problem, they are still restricted either in the type of data, the type of storage, or the size of data they can handle. In this paper, we propose a novel design of a platform for collecting and analyzing agricultural big data. The proposed platform supports (1) multiple methods of collecting data from various data sources using Flume and MapReduce; (2) multiple choices of data storage including HDFS, HBase, and Hive; and (3) big data analysis modules with Spark and Hadoop.

• The KIPS Transactions:PartD
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• v.15D no.6
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• pp.733-740
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• 2008

Recently, mobile computing devices are used popularly. And quantity of information on mobile computing devices is being increased due to digitalization of information. So it needs an embedded DBMS for effective information management. Furthermore, since flash memory having a restriction on the number of partial write cycles is rapidly deployed on mobile computing devices as data storage and is more expensive than the conventional magnetic hard disk, the compressed data management system(CDMS) has been considered as an effective storage management technique for mobile computing devices in previous research. However, the research of CDMS is at the initial stage and has several problems. Hence, in this paper, we present additional storage management methods to solve the problems and improve the effectiveness of the CDMS for embedded DBMS.

• Journal of Digital Contents Society
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• v.14 no.1
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• pp.15-23
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• 2013

In response to the demands of large-scale data processing with low-power and new application, a storage system using SSD (Solid State Disk/Drive) with fast input-output performance instead of hard disc has appeared as storage device. Studies on methods to overcome specific problems of SSD such as various processing data units, out-place-update and limited delete count have been actively conducted. However, declining performance and stability have not been resolved yet when storing case specific data with small scale that causes frequent random write in hard disc or SSD. This thesis suggests a system structure that stores index requesting frequent random write in NVRAM capable of byte access by using characteristics such as byte unit fast read / write of NVRAM, non-volatile and smaller size of actual changed data size in index page than block size.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10c
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• pp.6-11
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• 2006

최근 휴대용 정보기기 사용이 보편화되어지고 있는 가운데 정보의 디지털화로 인해 휴대용 정보기기에서 처리되어야 하는 정보가 무수히 많아지고 있다. 이로 인해 휴대용 정보기기에서는 정보들을 효과적으로 관리하기 위해 임베디드 DBMS의 사용이 요구되고 있다. 또한 휴대용 정보기기에서 보편적으로 사용되는 저장장치는 NAND형 플래시 메모리로 단위 공간당 비용이 기존의 하드디스크에 비해 수십배 가량 높아 저장 공간의 효율적인 관리가 요구되고 있다. 따라서 본 논문에서는 플래시메모리를 저장매체로 사용하는 DBMS에서 압축기법을 사용한 효율적인 데이터 관리 시스템을 제안한다. 제안되는 압축 기반 시스템은 저장 공간과 데이터I/O를 줄이며, 데이터I/O를 줄임으로써 DBMS의 성능향상과 플래시 메모리의 수명을 연장시키는 효과를 기대할 수 있다.

• Journal of Digital Convergence
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• v.14 no.11
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• pp.283-288
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• 2016

This research is to study IoT based implementation of system and network for medical information processing. This paper's configuration environment consists of sensor node, gateway and server node as a basic IoT architecture. Medical terminal as a sensor node asks connect request to his server, and the server accepts the request if the medical device is already registered. Wearable medical device sends its collected sensing data to server, and server processes the received data for data visualization or saves them for usage in the future. This paper describes overall processes and their algorithms and suggests their software processing architecture.

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.639-642
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• 2008

In this paper, we present the storage manager for digital broadcast environment. Data stream in real-time broadcast environment flows into set-top box continuously but, Given the file-system doesn't consider such characteristics. The storage manager provides reliability and flexibility for digital broadcast in set-top box.