• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.1
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• pp.57-65
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• 2012

People leave voicemails or record phone conversations in their daily cell phone use. Sometimes important voice data is deleted by the user accidently, or purposely to cover up criminal activity. In these cases, deleted voice data must be able to be recovered for forensics, since the voice data can be used as evidence in a criminal case. Because cell phones store data that is easily fragmented in flash memory, voice data recovery is very difficult. However, if there are identifiable patterns for the deleted voice data, we can recover a significant amount of it by researching images of it. There are several types of voice data, such as QCP, AMR, MP4, etc.. This study researches the data recovery solutions for EVRC codec and AMR codec in QCP file, Qualcumm's voice data format in cell phone.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.3
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• pp.61-71
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• 2014

As the occupancy rate of the flash memory increases in the storage media market for the embedded system and the semi-conductor industry grows, the demand and supply of flash memory is increasing by a big margin. They are especially used in large quantity in the smart phones, tablets, PC, SSD and Soc(System on Chip) etc. The flash memory is divided into the NOR type and NAND type according to the cell arrangement structure and the NAND type is divided into the SLC(Single Level Cell) and MLC(Multi Level Cell) according to the number of bits that can be stored in each cell. Many tests have been performed on NOR type such as BIST(Bulit-In Self Test) and BIRA(Bulit-In Redundancy Analysis) etc, but there is little study on the NAND type. For the case of the existing BIST, the test can be proceeded using external equipments like ATE of high price. However, this paper is an attempt for the improvement of credibility and harvest rate of the system by proposing the BIST for the MLC NAND type flash memory of Finite State Machine structure on which the pattern test can be performed without external equipment since the necessary patterns are embedded in the interior and which uses the MLC NAND March(x) algorithm and pattern which had been proposed for the MLC NAND type flash memory.

• The Journal of Society for e-Business Studies
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• v.8 no.3
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• pp.165-176
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• 2003

Instead of existing cell phones, PDAs are observed as leading wireless Internet devices recently Numerous applications are developed by extended usage of PDAs and it should be installed appropriately according to devices. Furthermore, when battery is discharged, all data stored in RAM(Random Access Memory) becomes obsolete. So it should be recovered or reinstalled from flash memory, backup media or something. In this paper, we present an automatic application installation system(PAIS : PDA Automatic Installation System) to solve problems that users have to install applications by themselves whenever it is necessary. With this system, users feel comfortable by saving time and effort to install each applications and application development companies save cost needed to make materials illustrating installation process. Consequently PAIS may flourish wireless Internet business.

• Journal of Korean Public Health Nursing
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• v.29 no.1
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• pp.5-17
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• 2015

Purpose: The purpose of this study was to demonstrate the moderating effect of smartphone addiction on the relationship between interpersonal problem and depression. Methods: From 21 to 30 May 2013, a convenience sample of 192 subjects was recruited. Research data were collected via questionnaires and analyzed using SPSS version 18.0. Results: Scores for female students were higher than those for male students in smartphone addiction, interpersonal peoblems and depression. The average BDI score was 6.6. There were 29(15.1%), 11(5.7%), 8(4.0%), and 6(3.1%) students with mild, moderate, and severe depression, respectively. Significant positive correlation between smartphone addiction, interpersonal problems and depression. The moderating effect of smartphone addiction on the relationship between interpersonal problems and depression was significant. Conclusion: Smartphone addiction plays a role as a moderating variable influencing the relationship between interpersonal problems and depression, and also increases the effect of interpersonal problems on depression. When developing depression prevention programs for college students, such programs should consider strategies to decrease smartphone addiction and increase direct interpersonal relationship, and female students in particular should be included in such programs.

• Journal of Sensor Science and Technology
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• v.29 no.5
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• pp.283-292
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• 2020

Current sensors that use a Hall element and Hall IC to measure the magnetic fields generated in steel silicon core gaps do not distinguish between direct and alternating currents. Thus, they are primarily used to measure direct current (DC) in industrial equipment. Although such sensors can measure the DC when installed in expensive equipment, ascertaining problems becomes difficult if the equipment is set up in an unexposed space. The control box is only opened during scheduled maintenance or when anomalies occur. Therefore, in this paper, a method is proposed for facilitating the safety management and maintenance of equipment when necessary, instead of waiting for anomalies or scheduled maintenance. A Bluetooth 4.0 low-energy current-sensor system based on near-field communication is used, which compensates for the nonlinearity of the current-sensor output signal using a piecewise linear model. The sensor is controlled using its generic attribute profile. Sensor nodes and cell phones used to check the signals obtained from the sensor at 50-A input currents showed an accuracy of ±1%, exhibiting linearity in all communications within the range of 0 to 50 A, with a stable output voltage for each communication segment.

• Journal of Applied Reliability
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• v.9 no.2
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• pp.131-148
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• 2009

An organic light emitting diode (OLED), also light emitting polymer (LEP) and organic electro luminescence (OEL), is any light emitting diode (LED) whose emissive electroluminescent layer is composed of a film of organic compounds. The layer usually contains a polymer substance that allows suitable organic compounds to be deposited. They are deposited in rows and columns onto a flat carrier by a simple "printing" process. The resulting matrix of pixels can emit light of different colors. Such systems can be used in television screens, computer displays, small, portable system screens such as cell phones and PDAs, advertising, information and indication. OLEDs can also be used in light sources for general space illumination, and large-area light-emitting elements. In this paper, we develop the general guide line of the accelerated life test for assuring B10 life of AMOLED(Active Matrix Organic Light Emitting Diode) and PMOLED(Passive Matrix Organic Light Emitting Diode) which are widely used for display monitor less than 115 mm.

• Korean Journal of Human Ecology
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• v.18 no.5
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• pp.1063-1075
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• 2009

This study intends to provide foundational data for enhancing the welfare of customers purchasing digital products through analyzing the notes from written on-line reviews. The data used for the analysis are 6,342 on-line reviews for cell phones and digital cameras released from November, 2007 until April, 2008, which was posted on Naver Knowledge Shopping from November, 2007 until June, 2008. Through the on-line reviews, this article analyzed the evaluations on the digital products' hardware, software, design, service, price, and other criteria and the customers' emotional experience in the process of purchase, use, and possession. According to the results of the analysis, negative evaluation and emotional experience were originated from the company's information provision methods and purchase process. In addition, insufficient information searches in the process of online purchases, consumers' low right consciousness, and impolite on-line reviews were also problematic. Customers' evaluations and emotional experiences on digital products were conducted in a complex way. Based on that, this research makes suggestions in the company's marketing, customer education, and theoretical aspect.

• Journal of Multimedia Information System
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• v.2 no.2
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• pp.233-240
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• 2015

Mobile devices are becoming increasingly sophisticated and the latest generation of smartphones now incorporates many diverse and powerful sensors. These sensors include acceleration sensor, magnetic field sensor, light sensor, proximity sensor, gyroscope sensor, pressure sensor, rotation vector sensor, gravity sensor and orientation sensor. The availability of these sensors in mass-marketed communication devices creates exciting new opportunities for data mining and data mining applications. In this paper, we describe and evaluate a system that uses phone-based accelerometers to perform activity recognition, a task which involves identifying the physical activity that a user is performing. To implement our system, we collected labeled accelerometer data from 10 users as they performed daily activities such as "phone detached", "idle", "walking", "running", and "jumping", and then aggregated this time series data into examples that summarize the user activity 5-minute intervals. We then used the resulting training data to induce a predictive model for activity recognition. This work is significant because the activity recognition model permits us to gain useful knowledge about the habits of millions of users-just by having them carry cell phones in their pockets.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.737-742
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• 2009

As increasing emphasis is being placed on user experience design, the RIA technology is widely deployed for user interface and software operation on embedded devices including cell phones and TVs. In particular, RIA-based IPTV enables creation of various interactive contents via sophisticated animation and various input devices. This paper proposes a service framework for emotional contents on broadcast and communication-converged IPTV systems. We design a programming interface extension for IPTV-based flash contents and develop a prototype of flash runtime with the extended programming support. Since the proposed runtime was carefully designed to fully utilize the built-in graphic acceleration hardware in media processor, it supports high resolution graphic animation in resource-constrained IPTV environments.

• International Journal of Costume and Fashion
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• v.4 no.2
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• pp.45-55
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• 2004

Rapid informatization and technology advance in the 21st century has invited a new paradigm and changed many things in human life pattern. The impact of mobility seen in this digital nomadism has brought about, when it comes to clothing, a change in its unique meaning, that is, the graftage of high technology onto present nomad's life style who live moving around all the time due to the expansion of mobile environment. As the fruits of this expansion of mobile environment and technology advance in wireless telecommunication, easy-to-carry smaller sized devices such as cell phones, PDA, and MP3 players represent the present times, while the future would be an 'era of wearing' in which kinds of electronic devices and systems are integrated into clothing. Thus in this study, concept of wearable computer seen in the 21st century's digital nomadism was reviewed, and figurativeness and anesthetic value of wearable computer were discussed in association with the change in high style image resulted from technology advance and change of life style. By drawing a justice from which, value of future fashion was also prospected.