• Journal of the Korean Electrochemical Society
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• v.10 no.1
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• pp.31-35
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• 2007

In this review article, we are going to explain the recent development of lithium secondary batteries for a cellular phone. There are three kinds of rechargeable batteries for cellular phones such as nickel-cadmium, nickel-metal hydride, and lithium ion or lithium ion polymer. The lithium secondary battery is one of the most excellent battery in the point of view of energy density. It means very small and light one among same capacity batteries is the lithium secondary battery. The market volume of lithium secondary batteries increases steeply about 15% annually. The trend of R&D is focused on novel cathode materials including $LiFePO_4$, novel anode materials such as lithium titanate, silicon, and tin, elecrolytes, and safety insurance.

• Journal of Korean Electronics
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• v.10 no.4
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• pp.56-61
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• 1990

• Journal of Korean Academy of Nursing
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• v.41 no.5
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• pp.724-731
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• 2011

Purpose: The purpose of this study was to investigate the effectiveness of an educational intervention that used both cellular phones and the Internet to provide a short messaging service (SMS) relating to blood glucose, blood pressure, and serum lipid levels in postmenopausal women with impaired fasting glucose (IFG). Methods: Twenty-eight postmenopausal women were assigned to an intervention group and twenty-one postmenopausal women to a control group. The intervention was provided for 12 weeks. Patients in the intervention group were asked to access a web site by using a cellular phone or to use the Internet directly and input their blood glucose and blood pressure levels weekly. Participants were sent the optimal recommendations weekly by both cellular phone and Internet. Results: The intervention group had a mean decrease in systolic blood pressure (SBP) level of 8.1 mmHg but changes for the control group were not significant. There was a significant mean change in diastolic blood pressure (DBP) level for the intervention group (-7.7 mmHg). The mean change in the control group was not significant. Conclusion: This educational intervention using the Internet and a SMS by cellular phone improved levels of SBP and DBP in postmenopausal women with IFG.

• Fire Science and Engineering
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• v.25 no.6
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• pp.21-26
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• 2011

The purpose of this paper is to present the damage patterns of cellular phone (SCH_W830) batteries according to energy sources and have them utilized as data for the settlement of disputes between manufactures and consumers. The reliability was secured by maintaining the ambient temperature and humidity at $22{\pm}2^{\circ}C$ and 40~60 %, respectively. The voltage of the battery used for the tests was measured to be 4.18V between positive pole (+) and negative pole (-)(1), and 4.19 V between positive pole (+) and negative pole (-)(2). This study applied the Korean Industrial Standard (KS) to the flammability test of cellular phones due to a general flame applied to them and found that no damage occurred to the built-in battery even though the flame was applied to the cases of cellular phones for 30 seconds. From the results of immersing the cellular phones in the saline solution (NaCl, 0.9 %) for 180 seconds, it was found that there was a trace of carbonization and melting due to the heat caused by leaking current. It can be seen that when the cellular phones were heated for 70 seconds using a microwave oven (MWO), the areas containing the metal holder, recharging connector, antenna, etc., were melted and discolored and that other areas showed no particular problems. That is, while the external carbonization of cellular phones, built-in metals and dielectric materials, and damage and deformation of the battery terminal block, etc., occurred differently depending on the types of energy sources, the voltage showed comparatively constant characteristics. Therefore, it is thought to be possible to attribute the cause of damage to the battery by performing analysis taking into consideration comprehensively the characteristics of the flame spread pattern as well as the melting and deformation of metals.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.223-226
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• 2010

iPhone and Smart Phone domestic markets are activated with domestic coming out of galaxy S together and the users are increasing. It follows hereupon and with forensic techniques for the cellular phone relation criminal evidence collection of data of existing the mobile forensic engineering research is necessary in about Smart Phone where it has become new techniques and WiFi etc. Convergence. It respects Smart Phone OS star forensic technique and a tool research, iPhone Apple MAC OS X and it researches galaxy S Google Android from the present paper. Smart it uses SYN methods with Phone OS star forensic techniques and it researches in order mobile forensic description below it observes it sees and forensic application methods computer forensic methods and the tools and it researches forensic techniques. The present paper research as IT powerful country will contribute in Smart Phone forensic technical advances of Korea.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.05a
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• pp.554-559
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• 2005

It seems to be dangerous to use a cellular phone while driving since it increases driver's mental stress and makes driver's reaction time slow. This study is to investigate driver's psycho-physiological responses on mobile telephoning while driving. Among the three experimental factors (mobile-phone types, message IODs over mobile-phone, road types), only the message IODs over mobile-phone changed R-R intervals of electrocardiograph significantly. This result suggests that the regulations on the mobile telephoning while driving be changed.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.7
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• pp.1065-1074
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• 2013

The study examined how the risk perception of cellular phone electromagnetic waves' possibility to harm human bodies would be psychologically different by gender and age. The study measured the risk perception targeting a total of 1,001 men and women in their twenties and more living in six major cities in Korea. According to the results, for the risk perception by gender, the women would recognize the risk of cellular phone electromagnetic waves more than the men. Among the women, those in their fifties appeared to have the greatest risk perception. In particular, the risk perception difference by age and gender was observed to be affected by psychological factors and, the study should be regarded academically significant for having verified the importance. For general people, they would perceive the risk via those psychological factors as experiences in daily life. Therefore, in order to relieve social conflicts caused by the risk, basic risk communication based on proper understanding of how the general people would recognize the risk should be provided. Hence, the study is expected to be a chance for intervention strategy research on how our community would proceed with communication and how the community, again, apprehends the cellular phone electromagnetic waves as well.

• Journal of Digital Convergence
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• v.11 no.5
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• pp.285-290
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• 2013

In a MPC coding using excitation source of voiced and unvoiced, it would be a distortion of speech waveform. This is caused by normalization of synthesis speech waveform of voiced in the process of restoration the multi-pulses of representation section. To solve this problem, this paper present a method of position compensation(PC-MPC) in a multi-pulses each pitch interval in order to reduce distortion of speech waveform. I was confirmed that the method can be synthesized close to the original speech waveform. And I evaluate the MPC and PC-MPC using multi-pulses position compensation method. As a result, $SNR_{seg}$ of PC-MPC was improved 0.4dB for female voice and 0.5dB for male voice respectively. Compared to the MPC, $SNR_{seg}$ of PC-MPC has been improved that I was able to control the distortion of the speech waveform finally. And so, I expect to be able to this method for cellular phone and smart phone using excitation source of low bit rate.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.4
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• pp.780-788
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• 2011

This paper suggests one model, which can be monitor and control target system at anytime and anywhere by a WAP and ME based personal cellular phone(Feature phone) and internet connection. The suggesting model tried to overcome constraints of distance and mobility of conventional methods, TCP/IP based remote data monitoring system, which combine PDA and WLAN technologies. For the experiments of suggesting model, the target systems are constructed with individual modules, which need AC or DC power control. The development software for the control and monitor of local system use NI Labview for the easy-programming and confidence. Also, web server use APM setup for the general user. The mobile connection environments of personal cellular phone are programmed by use WML and mHTML language for the general access. Through the experiments, we have showed that suggesting model can overcome constraints of distance and mobility of conventional system.

• Journal of Digital Convergence
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• v.12 no.6
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• pp.271-276
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• 2014

In a speech coding system using excitation source of voiced and unvoiced, it would be involved a distortion of speech quality in case coexist with a voiced and unvoiced consonants in a frame. In this paper, I propose a method of 8kbps Multi-Pulse Speech Coding(FBD-MPC: Frequency Band Division MPC) by using TSIUVC(Transition Segment Including Unvoiced Consonant) searching, extraction and approximation-synthesis method in a frequency domain. I evaluate the 8kbps MPC and FBD-MPC. As a result, SNRseg of FBD-MPC was improved 0.5dB for female voice and 0.2dB for male voice respectively. Compared to the MPC, SNRseg of FBD-MPC has been improved that I was able to control the distortion of the speech waveform finally. And so, I expect to be able to this method for cellular phone and smart phone using excitation source of low bit rate.