• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• 제20권3호
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• pp.197-204
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• 2008

DMFC(Direct Methanol Fuel Cell) is one of promising candidates for power sources of small mobile IT devices like notebook, cell phone, and so on. Efficient operation of fuel cell system is very important for long-sustained power supply because of limited fuel tank size. It is necessary to investigate operation characteristics of fuel cell stack for optimal control of DMFC system. The generated voltage was modeled according to various operating condition; methanol concentration, stack temperature, and load current. It is inevitable for methanol solution at anode to cross over to cathode through MEA(membrane electrode assembly), which reduces the system efficiency and increases fuel consumption. In this study, optimal operation conditions are proposed by analyzing stack performance model, cross-over phenomenon, and system efficiency.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 한국소성가공학회 2008년도 추계학술대회 논문집
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• pp.422-425
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• 2008

Recently, electronic products and related parts are required to have thin thickness because of small form factor. To go with the trend, LGP(light guide plate) of LCD BLU(Liquid Crystal Display Back light unit: It is one of kernel parts of LCD) for cell phone has the thickness of 0.3 mm and the battery case of cell phone has 0.25 mm. Accordingly, high speed injection molding is required to make products which have thin thickness. High speed injection molding means that the resin is injected into the cavity at higher than normal speed avoiding short shot. In the case of hydro-mechanical high speed injection machine, it requires the design for hydraulic unit to make high injection speed and the design for control unit to control hydraulic unit. In the present paper, we concentrated on the molding stability of hydro-mechanical high speed injection machine to make an LGP of 0.3 mm thickness.

• Journal of Korea Society of Digital Industry and Information Management
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• 제11권2호
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• pp.11-22
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• 2015

The almost of Web page has been gathered the personal information(Korean resident registration number, name, cell-phone number, home telephone number, E-mail address, home address, etc.) using the membership and log-in. The all most user of Web page are concerned for gathering of the personal information. I-pin is the alternative means of resident registration number and has been used during the last ten-year period in the internet. The accident of I-pin mass illegal issue was happened by hacker at February, 2015. In this paper, we analysis the problems of I-pin system about I-pin mass illegal issue accident and propose a improvement method of it. First, I-pin issue must be processed by the off-line of face certification in spite of user's inconvenience. Second, I-pin use must be made up through second certification of password or OTP. The third, the notification of I-pin use must be sent to the user by the text messaging service of cell-phone or the E-mail. The forth, I-pin must be used an alternative means of Korean resident registration number in Internet. The methods can reduce the problems of I-pin system.

• Journal of the Korea Institute of Information Security & Cryptology
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• 제23권1호
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• pp.19-32
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• 2013

As cyber stock trading grows rapidly, stock trading using Home Trading System have been brisk recently. Home Trading System is a heavy-weight in the stock market, and the system has shown 75% and 40% market shares for KOSPI and KOSDAQ, respectively. However, since Home Trading System focuses on the convenience and the availability, it has some security problems. In this paper, we found that the authentication information in memory remains during the stock trading and we proposed its countermeasure through two-channel authentication using a mobile device such as a cell phone.

• The Transactions of the Korean Institute of Power Electronics
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• 제9권2호
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• pp.187-193
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• 2004

For a power source of usual electronic devices such as PDA, smart phone, UPS and electric vehicle, the battery made of serially connected multiple cells is generally used. In this case, if there are some unbalanced among cell voltages, the total lifetime and the total capacity of the battery are limited to a lower value. To maintain a balanced condition in cells, an effective method of regulating the cell voltage in indispensable. In this paper, we propose the design of a balancing circuit for electronic appliances. The balancing system was controlled by a micro-controller which enables to implement the balancing action during charging period. Proposed method has been verified by the experiment using the charger and recorder. The experimental results show that the individual battery equalization can improve battery capacity and battery lifetime and performance through an extended operational time.

• Transactions of Materials Processing
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• 제17권8호
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• pp.657-661
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• 2008

Recently, products of electronic industry and related parts are required to have the thickness thinner and thinner to reduce the part weight. To go with this trend, LGP(light guide plate) of LCD-BLU(Liquid Crystal Display-Back Light Unit: It is one of kernel parts of LCD) for cell phone has the thickness of ${\sim}0.3mm$ and the battery case of cell phone has ${\sim}0.25mm$. Accordingly, high speed injection molding is required to mold products which have thinner parts. To achieve high speed injection and proper control of hydraulic unit, various design was applied to conventional injection unit. In the present paper, we concentrated on the molding stability of hydro-mechanical high speed injection machine to make an LGP of 0.3mm thickness.

• Journal of the Semiconductor & Display Technology
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• 제20권4호
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• pp.6-9
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• 2021

The 3D industry is drawing attention for its applications in various markets, including architecture, media, VR/AR, metaverse, imperial broadcast, and etc.. The current feature of the architecture we are introducing is to make 3D models more easily created and modified than conventional ones. Existing methods for generating 3D models mainly obtain values using specialized equipment such as RGB-D cameras and Lidar cameras, through which 3D models are constructed and used. This requires the purchase of equipment and allows the generated 3D model to be verified by the computer. However, our framework allows users to collect data in an easier and cheaper manner using cell phone cameras instead of specialized equipment, and uses 2D data to proceed with 3D modeling on the server and output it to cell phone application screens. This gives users a more accessible environment. In addition, in the 3D modeling process, object classification is attempted through deep learning without user intervention, and mesh and texture suitable for the object can be applied to obtain a lively 3D model. It also allows users to modify mesh and texture through requests, allowing them to obtain sophisticated 3D models.

• Journal of the Institute of Electronics Engineers of Korea SD
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• 제47권3호
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• pp.35-40
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• 2010

In this paper, we propose a hardware resource sharable camera control processor (CCP) for low-cost and low-power camera cell phones. The main idea behind the proposed architecture is that adds direct access paths in the CCP to share its hardware resources so that the baseband processor expands its capabilities and boosts its performance by utilizing CCF's hardware resources. In addition, we applied a module grain dock-gating method to reduce power dissipation. Hence, the CCP can realize low-power and low-cost camera cell phones with greater hardware efficiency. This chip was fabricated in a 0.18um CMOS process with an active area of $3.8mm\;{\times}\;3.8mm$.

• Journal of Korean Academy of Fundamentals of Nursing
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• 제15권2호
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• pp.134-142
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• 2008

Purpose: This study was done to identify satisfaction with the method of evaluating practical skills in fundamental nursing through cellular phone animation self-monitoring and feedback. Method: The participants were 163 first-year student nurses. Data were collected from October 1 to 5 2007 using a structured questionnaire. Results: The average score for satisfaction was 3.65(${\pm}.69$) and the highest score was for the item, "I was pleased to have the opportunity of relearning by looking back at my behaviors through self monitoring" with 4.05(${\pm}.89$). The average score for dissatisfaction was 3.23(${\pm}.90$) and the highest score was "I memorized only orders according to the checklist" with 3.65(${\pm}.97$). The practical tests method showed a significant difference according to motivation for application to college of nursing (F=3.11, p=.047). There was a significant positive correlation between practical education satisfaction and test method (r=.363, p=.000). Conclusion: These findings show that there is a need to develop strategies to improve practical test methods for student nurses.

• Child Health Nursing Research
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• 제13권4호
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• pp.506-511
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• 2007

Purpose: The purpose of this study was to investigate effect of distraction by use of a cellular phone on pain and fear during venipuncture procedure for hospitalized preschool children. Method: Fifty four preschool children aged 3-6 were recruited from one university affiliated hospital in Daegu. Participants were assigned to the control(n=27) to receive usual care or intervention group(n=27) to receive distraction plus usual care. For the assessment of children's pain, FACE scale and mothers' perceptions of their own children's pain, visual analogue scale(VAS) were used. For the assessment of fear, Procedure Behavioral checklist developed by Lebaron and Zeltzer was used. Results: Results showed that intervention group demonstrated significantly less pain scores on FACE(t=2.19, p<.03) as rated by children and on VAS(t=2.78, p<.01) as rated by their mothers. Intervention group showed also significantly less fear scores(t=2.30, p<.02) as rated by the researcher. Conclusion: Distraction with cell phone for relieving pain and fear during venipuncture procedure was effective for the hospitalized preschool children.