• The KIPS Transactions:PartA
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• v.9A no.4
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• pp.399-404
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• 2002

Along the evolution of information and communication technologies, manufacturing embedded systems such as PDA (personal digital assistant), HPC (hand -held PC), settop box. and information appliance became realistic. And RTOS (real-time operating system) and filesystem have been played essential re]os within the embedded systems as well. For the filesystem of embedded systems, flash memory has been used extensively instead of traditional hard disk drives because of embedded system's requirements like portability, fast access time, and low power consumption. Other than these requirements, nonvolatile storage characteristic of flash memory is another reason for wide adoption in industry. However, there are some technical challenges to cope with to use the flash memory as an indispensable component of the embedded systems. These would be relatively slow cleaning time and the limited number of times to write-and-clean. In this paper, a new cleaning policy is proposed to overcome the problems mentioned above and relevant performance comparison results will be provided. Ranking cleaning policy(RCP) decides when and where to clean within the flash memory considering the cost of cleaning and the number of times of cleaning. This method will maximize not only the lifetime of flash memory but also the performance of access time and manageability. As a result of performance comparison, RCP has showed about 10 ~ 50% of performance evolution compared to traditional policies, Greedy and Cost-benefit methods, by write throughputs.

• Korean Security Journal
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• no.26
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• pp.59-87
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• 2011

Security Business Act of Korea is leaning toward the aspect of regulation, while it provides few provisions about vesting the authority, which causes problems such as legal loopholes to be raised in regard to the rules about authorizing the private security personnel to perform security affairs properly and defining the limit of power. So, it should be done to interpret the law in order to draw the legal basis of empowering as well as to set limits of the authority of security main agent, and Article 7, Section 1, of Security Business Act is the very provision that involves the legal basis. In the scope of 'Management Power', the statutory authority in the first clause of Article 7 of Security Business Act, the security personnel can use force for self-defense, defense of others and property, and prevention of crimes. In addition, the powers of interrogation, access control, and eviction notice are involved in its scope. The private security personnel as the occupation assistant can take precautions and if the infringement on the benefit and protection of the law is imminent or done, he or she can use force within the limits of the passive resistance and the means of defiance on the basis of 'Management Power'. The private security personnel, however, can exercise the force only if the necessary conditions of legal defense, emergency evacuation, and legitimate act of criminal law are fulfilled.

• The Journal of Society for e-Business Studies
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• v.21 no.1
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• pp.79-90
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• 2016

Autonomous knowledge service, a fully-automated and pervasive service for knowledge acquisition and support based on the power of recent ITs is gaining tremendous interest more and more, as not only the level of users' intelligence increases but also the maturity of IT infrastructure improves. Conventional approaches of knowledge service, however, could not satisfy users because they usually provided undesired knowledge which had been acquired without considering users' want. In other words, knowledge acquisition and distribution were separately performed. This research, therefore, suggests an amended autonomous knowledge service framework by fully-automating the whole phases of knowledge life cycle, from knowledge acquisition to distribution. ASKs, the prototype system of this research, is also implemented by defining and specifying component technologies which constituently compose suggested framework. More user-friendly and applicable way of knowledge service will be derived and facilitated through this research.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.152-152
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• 2016

We studied the effect of the silver grid size on graphene transparent conducting films for flexible organic solar cells (OSCs). The silver grid was used an assistant layer of the graphene to reduce the sheet resistance of substrates. Silver grid with various graphene sizes for optimizing transmittance and sheet resistance of substrates were fabricated on polyethylene terephthalate (PET) substrates to form the hybrid films. The optimized grid geometry on the single layer graphene (SLG) was the grid dimension $200{\mu}m{\times}200{\mu}m{\times}50nm{\times}2{\mu}m$ (length ${\times}$ width ${\times}$ height ${\times}$ linewidth), where the sheet resistance was $55.73{\Omega}/square$ with the average transmittance of ~ 92.83 % at 550 nm. The properties of the OSCs fabricated using SLG with optimized silver grids on PET substrates show a short circuit current of $10.9mA/cm^2$, an open circuit voltage of 0.58 V, a fill factor of 60.8 %, and a power conversion efficiency (PCE) of 3.9 %. The PCE was improved about 91% than that of the OSCs using the SLG without the silver grid. These results demonstrate that the optimized grid geometry to the based on the graphene transparent electrodes contribute to improving the performance of OSCs.

• Smart Media Journal
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• v.4 no.2
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• pp.17-25
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• 2015

In this paper proposes an idea for using NFC(Near Field Communication) on smalt mobile devices, you can easily control the electric wheelchair system. In this system with previous researches controlled a power wheelchair in a mobile device using Bluetooth communication, the board communicates with the integrated control of the wheelchair. With smart mobile devices, the wheelchair control board integrating the signal generated by checking real time so that the user can easily monitor the state of the wheelchair. Users are using smalt mobile devices, the wheelchair can be controlled easily, and the setting at any time according to the state of the individual and can be used. HEX format control is directly in hardware, allowing analysis was read, the user settings are typically used to match cards which support NFC technology such as bus card for registration, storing the selected information and enable read and were applicable. By applying this system, wheelchairs oriented aids disabled and older people able to access to provide with stability.

• The Journal of the Korean dental association
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• v.52 no.12
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• pp.734-743
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• 2014

Objectives: By introduced reciprocation motion file in dentistry, dentists benefit simple canal shaping procedure and time-saving. But, reciprocation motion generates uncomfortable vibration to doctors and patients. Because there was no study about this consideration, this study compared vibration pattern and power generated from reciprocation motion motor and conventional rotary motor. Materials & Methods: One conventional rotary motor; X-Smart (Dentsply Maillefer, Ballaigues, Switzerland); and two reciprocating motors; WaveOne Motor (Dentsply Maillefer, Ballaigues, Switzerland) and X-SMART PLUS (Dentsply Maillefer, Ballaigues, Switzerland); were used in this study. Triaxial $ICP^{(R)}$ Accelerometer (Model 356A12, PCB piezotronics, New York, USA) was attached on motor's handpiece head, and was measured tri-axial vibratory acceleration with NI Sound and Vibration Assistant 2009 software (National Instruments, Texas, USA). Mean vibratory acceleration and maximum vibratory acceleration was measured on fixed position and handed position. The results of vibratory acceleration were statistically analyzed using ANOVA and multiple comparisons are made using Turkey's test at p<0.05 level. Results: Reciprocating motors showed higher mean vibratory acceleration and maximum vibratory acceleration than conventional rotary motor (p<0.05). Between reciprocating motors, X-SMART PLUS had lower mean vibratory acceleration and maximum vibratory acceleration than WaveOne Motor (p<0.05). Conclusion: Reciprocating motors generate more vibration than conventional rotary motor. Further study about effect of vibration to dentist and patient is needed. And it seems to be necessary to make a standard about vibration level in endodontic motors.

• Korean Journal of Childcare and Education
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• v.7 no.2
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• pp.19-41
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• 2011

The purpose of this study is to find the relationship between the infants' mother's parenting stresses and their environmental factors. The participants were 625 employed and 1453 non employed mothers from the Korean children panel in 2008. The collected data were analyzed by t-test and hierarchical regressions. The results are as follows. 1) The infant mothers experienced the medium level of parenting stresses. They reported the high level stresses in the parenting costs, the selecting parenting information, and the responsibility in their child's emotional stability. 2) The non employed mothers perceived more difficulties in the parenting situations than the employed mothers. The employed mothers perceived their environment and their parenting itself in positive way. They were in the good psychological conditions, having a well relationship with the husbands. They also had more knowledge in the child rearing and social supports. 3) The mother's psychological factors showed the high explanation power on their parenting stresses. 4) The father's parenting assistant affected the mother's parenting stresses only in the non employed mother.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.5
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• pp.378-384
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• 2003

Etching species in CF$_4$/Ar plasma and the behavior of etching rate of Bi$_4$-$_{x}$L$_{x}$rTi$_3$O$_2$ (BLT) films were investigated in inductively coupled plasma (ICP) reactor in terms of etch parameters. The etching rate as functions of CF$_4$ contents showed the maximum 803 $\AA$/min at 20% CF$_4$ addition in CF$_4$/Ar plasma. The increase of RF power and DC bias voltage caused to an increase of etch rate. The variation of relative volume densities for F and he atoms were measured with the optical emission spectroscopy (OES). The chemical states of BLT were investigated with using X-ray photoelectron spectroscopy (XPS). XPS narrow scan analysis shows that La-fluorides remained on the etched surface. The presence of maximum etch rate at CF$_4$(20%)/Ar(80%) may be explained by the concurrence of two etching mechanisms such as physical sputtering and chemical reaction. The roles of he ion bombardment include destruction of metal (Bi, La, Ti)-O bonds as well as assistant for chemical reaction of metals with fluorine atoms.oms.

• Journal of Digital Convergence
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• v.19 no.9
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• pp.393-400
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• 2021

Purpose: The purpose of this study was to provide basic data for intervention development programs that could improve the attachment of first-time mothers. Methods: Data were collected from 148 Primipara Women in S city from April 1 to May 31, 2021. Data were processed using descriptive statistics, t-test, ANOVA, correlation analysis, and stepwise regression analysis. Results: As a result of the study, mother-to-infant attachment was negatively correlated with maternal fatigue(r=-.65, p<.001) and anxiety level(r=-.62, p<.001). Maternal fatigue(β=-.52), anxiety level(β=-.48), Child care assistant(β=.10) affect the attachment of first-time mothers. Mother-to-infant attachment the total explanation power was 64.3%(F=89.19, p<.001). It is necessary to develop programs that reduce maternal fatigue and anxiety level based on factors affecting the mother-to-infant attachment of first-time mothers and improve the ability of the mother-to-infant attachment.

• Journal of Advanced Navigation Technology
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• v.24 no.6
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• pp.485-490
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• 2020

Recently, amid active research on domestic shipbuilding industry and IT convergence technology, with the development of satellite detection technology for ship safety operation, ships monitored the movement of ships with the mandatory long-range identification & tracking of vessels and automatic identification system. It is possible to help safe navigation, but it is necessary to develop safety device that alert the marine officer who rely on radar to correct conditions in case of weightlessness. Therefore, an ocean fog alarm system was developed to detect and inform using photo sensors. The fabricated ocean fog detect and alarm system consists of a small, low-power optical sensor transceiver and data sensing processing module. Through experiment, it is confirmed that the fabricated ocean fog detect and alarm system measure the corresponding concentration of ocean fog for fogless circumstance and fogbound circumstance, respectively. Furthermore, the fabricated system can control RPM of ship engine according to the concentration of ocean fog, and consequently, the fabricated system can be applied to assistant device for ship safety operation.