• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.6
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• pp.123-129
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• 2013

Android file system is vulnerable to the external access of system resources via its arbitrary access mode and need user's control for SD and UMS medias due to its open architecture. In response to the device control, there is a drawback that its controlability is valid only in the case of embedded linux kernel with VDC function. Hence the solution is to directly implement VDC through system call, with another security module for device storage than system module being added to android system. In this paper the new method of android storage access control for personal information is proposed via VDC for mount system of storage. The access method for SD and UMS were implemented using VDC and mount mechanism. This access control system has been designed to control the granted users in kernel level if files are flowed out by copying. As a result, it was proved through testing that the access control system has exactly detected the write access operation.

• Journal of the Semiconductor & Display Technology
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• v.18 no.4
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• pp.129-133
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• 2019

In this paper, we developed a system to monitor the storage capacity of suction-type device such as vacuum cleaner or crop harvesters. The monitoring system consists of load cells and a differential pressure sensor which simultaneously monitor the weight and volume of the stock. Since weighing objects stored in storage containers alone cannot fully monitor the level of filling, more accurate monitoring can be achieved by monitoring volume and fusion with weight information. The volume was monitored using a phenomenon in which the flow rate of the inhaled air varies depending on the volume of the object filled in the storage container. In this paper, we developed a system to monitor the storage in three stages: low, medium and high.

• Journal of Internet Computing and Services
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• v.17 no.3
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• pp.55-66
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• 2016

A local storage of HTML5 is a Web Storage, which is stored permanently on a local computer in the form of files. The contents of the storage can be easily accessed and modified because it is stored as plaintext. Moreover, because the internet browser classifies the local storages of each domain using file names, the malicious attacker can abuse victim's local storage files by changing file names. In the paper, we propose a scheme to maintain the integrity and the confidentiality of the local storage's source domain and source device. The key idea is that the client encrypts the data stored in the local storage with cipher key, which is managed by the web server. On the step of requesting the cipher key, the web server authenticates whether the client is legal source of local storage or not. Finally, we showed that our method can detect an abnormal access to the local storage through experiments according to the proposed method.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.1
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• pp.125-133
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• 2011

According to proliferation of mobile devices, security threats have been continuously increased such as illegal or unintentional file transmission of important data to an external mass-storage device. Therefore, we propose a protection method to prohibit an illegal outflow to this device and implement this method. This method extracts signatures from random locations of important file and uses them to detect and block illegal file transmission. To get signatures, a target file is divided by extracting window size and more than one signatures are extracted in this area. To effective signature sampling, various extraction ways such as full, binomial distribution-based and dynamic sampling are implemented and evaluated. The proposed method has some advantages. The one is that an attacker cannot easily predict the signature and its extraction location. The other is that it doesn't need to modify original data to protect it. With the help of these advantages, we can say that this method can increase efficiency of easy-to-use and it is a proper way leakage prevention in a mobile device.

• Transactions of the Society of Information Storage Systems
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• v.1 no.2
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• pp.115-120
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• 2005

As a popularity of a portable digital device such as a cellular phone, a digital camera and a MP3 player is spreading, the demand of the mobile storage device increases rapidly. A bluray technology using 405nm laser diode and objective lens having high NA(Numerical Aperture), 0.85, satisfies a miniaturization and a high capacity which are the requirements of the portable device. To develop SFFOP(small form factor optical pickup), it is prerequisite to minimize the number of optical components and establish evaluation and assembly method of micro optical pickup system as well as mass production method of micro optical component. To minimize optical elements of optical pickup, there have been many researches to use P-HOE(Polarized Holographic Optical Element) due to its extremely small size and versatile function. However, P-HOE is handled and assembled very accurately in SFFOP. In this paper, static error signal detection method is developed for an alignment of P-HOE in SFFOP. Using developed static error signal detection method, P-HOE can be aligned very accurately with real time result of static error signals of pickup such as FES(focusing error signal) and TES(Tracking Error Signal). The developed static error signal detection method is verified by the evaluation of commercialized DVD Pickup. And finally. developed static error signal detection method is applied for the assembly of P-HOE in SFFOP system satisfies specification of BD(Blu-ray Disk).

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.10a
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• pp.302-305
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• 2007

In recent years, many researches on new storage media with high capacity and information are developing. For manufacture of optical storage with high capacity, the injection molding process is generally used. In order to increase the filling ratio of the injection molding structure, the injection molding process required for high injection pressure, packing pressure and temperature control of the mold. However, conventional injection molding process is difficult to increase the filling ratio using injection master with the range of several nanometers and high aspect ratio. In order to improve and increase filling ratio of nano-structure with high aspect ratio, the active temperature control of injection mold was used. Experimental conditions were used injection pressure, time and temperature. Consequently, by using the peltier device into injection mold, we carried out the efficient and active temperature control of mold at low cost.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39A no.2
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• pp.86-91
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• 2014

Holographic data storage (HDS) has a number of advantages, including a high transmission rate through the use of a charge coupled device array for reading two-dimensional (2D) pixel image data, and a high density capacity. HDS also has disadvantages, including 2d intersymbol interference by neighboring pixels and interpage interference by multiple pages stored in the same holographic volume. These problems can be eliminated by modulation codes. We propose a 7/9 error-correcting modulation code that exploits a Viterbi-trellis algorithm and has a code rate larger (about 0.778) than that of the conventional 6/8 balanced modulation code. We show improved performance of the bit error rate with the proposed scheme compared to that of the simple 7/9 code without the trellis scheme and the 6/8 balanced modulation code.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.813-819
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• 2006

The state of the art for the design of swing ann actuators for optical disc drives is to obtain the high efficient dynamic characteristics, especially for the small size for the mobile information devices, It is affected by the need of consumers who wants the portable digital storage devices maintaining highly functional and removable characteristics of the optical disk drive (ODD). As a necessary consequence, the need of the small form factor (SFF) storage device has been considered as an important part in the information storage technology. In this paper. we suggest a new conceptual miniaturized swing arm type actuator that has high efficient dynamic characteristics as well as satisfies the sensitivity and the heat emission requirements for the SFF-ODD. It also uses a tracking electromagnetic (EM) circuit for a focusing motion. Due to the size constraint, the thermal problem of optical head arises; therefore, we design an efficiently heat emitted structure for the actuator.

• Communications of the Korean Institute of Information Scientists and Engineers
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• v.5 no.2
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• pp.105-107
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• 1987

A storage tube, Tektronix 4010, was added to NOVA 840 system at Korea Advanced Institute of Science in 1974 and efforts were made to develop an interactive graphics system. These include a software library, called TCS(Terminal Control System) [4], algorithms for hidden line and surface eliminations [5. 6], and two single user graphics systems based on different concepts involving graphic languages [2, 11]. A storage tube is a low-cost terminal, which is useful in certain applications, but introduces some problems since partial modification of the screen is not possible without erasing it entirely. Thus it has far reaching effects on the design of an interactive graphics system. The components of an interactive graphics system will be explained in section 2 and their relation ships with the choice of storage tube as the output device will be pointed out.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.45 no.3
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• pp.75-85
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• 2008

The DBMS are widely used in embedded systems. The flash memory is used as a storage device of a embedded system. The optimizer of existing database system assumes that the storage device is disk. There is overhead to overwrite on flash memory unlike disk. The block of flash memory should be erased before write. Due to this reason, query optimization model based on disk does not adequate for flash-aware database. Especially embedded system should minimize the consumption of energy, but consumes more energy because of excessive erase operations. This paper proposes new energy based cost model of embedded database and shows the comparison between disk based cost model and energy based cost model.