• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.230-235
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• 2008

With the advent of the telecommunication era, a mobile phone becomes a necessary communication device in modern society. For silent tactile signal, vibration motors have become one of the generic components in most mobile phones. Conventional vibration motors employ three-phase windings with mechanical brushes for commutation. However, mechanical commutation in these prior arts greatly deteriorates its life span, reliability, and productivity due to structural intricacy. This paper introduces a novel design of solenoid-type vibrators using electromagnetic and mechanical analysis. The proposed vibrators have a simpler structure and longer life span by eliminating wear-prone commutation parts in vibration motors.

• Journal of National Security and Military Science
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• s.9
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• pp.257-282
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• 2011

In this paper, we propose an architecture design of military operation system utilizing cellular networks. The main contribution of this paper is to provide a cost-effective military operation solution for ground forces, which is based on IT(information technology). By employing the cellular phones of officers' and non-commissioned officers' as the tools of operational communication, the proposed system can be constructed in the minimum duration and be built on the four components: command and control system, gateway, security system, and terminal(cell phone). This system is most effective for the warfare of limited area, but the effectiveness does not decrease under the total war covering the whole land of Korea. For the environmental change of near future, expanded architecture is also provided to utilize the functionalities of smart phones.

• Proceedings of the Korean Society for Quality Management Conference
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• 2006.04a
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• pp.100-105
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• 2006

Many corporations will get much mote benefits if they investigate the model deciding to purchasing mobile phone in that cell phone of our country has about 20% of market share in the world market. Considering this situation to divide cell phone market between CDMA and GSM in world market, it is not easy to make cell phone to satisfy the suitable method which each country wants. Through this study, we anticipate that it will offer the measuring method about consumer purchasing decision of each country. The research is to study how it is Effected by any factor when comsumer selects product and make research model. Based on the research model, we is to make a question. The research Is to complete the theoretical system on the basis of records about the cell phone and to study the improvement strategic using AHP and Conjoint Analysis which analyzes the consuming trend to customer's cell phone.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.3
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• pp.36-40
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• 2011

OFDM technology is already commonplace in the current mobile communication system environment. However, inter-cell interference causes many problems in the cellular system as seen from the problem caused by the surge in the use of smart phones. In this paper, we will research how user distribution influences a performance of a conventional proposed algorithm in the certain cell area and confirm it through computer simulations. As a result, we proved that there is an appropriate user distribution in the cell. In addition, it has an effect on the performance of inter-cell interference coordination.

• Journal of Electrochemical Science and Technology
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• v.10 no.2
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• pp.104-114
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• 2019

Energy is an essential driving force for modern society. In particular, electricity has become the standard source of power for almost every aspect of life. Electric power runs lights, televisions, cell phones, laptops, etc. However, it has become apparent that the current methods of producing this most valuable commodity combustion of fossil fuels are of limited supply and has become detrimental for the Earth's environment. It is also self-evident, given the fact that these resources are non-renewable, that these sources of energy will eventually run out. One of the most promising alternatives to the burning of fossil fuel in the production of electric power is the proton exchange membrane (PEM) fuel cell. The PEM fuel cell is environmentally friendly and achieves much higher efficiencies than a combustion engine. Water management is an important issue of PEM fuel cell operation. Water is the product of the electrochemical reactions inside fuel cell. If liquid water accumulation becomes excessive in a fuel cell, water columns will clog the gas flow channel. This condition is referred to as flooding. A number of researchers have examined the water removal methods in order to improve the performance. In this paper, a new water removal method that investigates the use of vibro-acoustic methods is presented. Piezo-actuators are devices to generate the flexural wave and are attached at end of a cathode bipolar plate. The "flexural wave" is used to impart energy to resting droplets and thus cause movement of the droplets in the direction of the traveling wave.

• Proceedings of the KIEE Conference
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• 2005.05a
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• pp.218-220
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• 2005

In this paper, we have designed a home network system based on WIPI. WIPI (Wireless Internet Platform for Interoperability) is the standard specification for the mobile platform made by the Mobile Platform Special subcommittee of the Korea Wireless Internet Standardization Forum(KWISP). The system consists of three parts - a server, client, and simulator, and all parts are developed with JAVA. People can control household appliances anytime, anywhere by using cell phones which can use the wireless Internet, so the system offers convenience to people.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.2
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• pp.253-259
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• 2011

In a ubiquitous society, the world is changing to the place where we can access to network anytime, anywhere, on any device. The mobile internet is leading the ubiquitous world and the most commonly used medium is a cell phone. However, it is uncomfortable to link to cafe, blog, and mini homepage. Because we have to stop wap service in order to upload the mobile contents like photos, videos, sound recordings produced by mobile phones. Also we have to re-access. So, in this paper content management system was designed and implemented which mobile users don't have to stop wap service in order to upload photos, videos, sound recordings produced by mobile phones. Also it supports upload in wap service integrative medicine diagnosis and contents can be managed by category.

• Journal of The Korean Association of Information Education
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• v.17 no.3
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• pp.367-373
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• 2013

This study elementary status of the investigation and analysis of smart phone use, and utilize of smart phones educational ways was carried out in order to investigate. In this study, factors commonly associated with the use of smart phones, in school area, gender, grade, and the need for a smart phone, smart phone using, whether for general cell phone use was a total of six tablets. General knowledge, attitude, practice about the factors and smart phone levels were analyzed using a smart phone and do not use the group's collective knowledge, attitudes, and practice levels were analyzed. To take advantage of the smart phone utilizing educational strategies were suggested, the general situation for smart phones and questionnaires were analyzed by a positive phenomenon. But Educational effect was neutral or negative views. We suggest the analysis of the educational utilization of smartphones on elementary students.

• Journal of Korea Multimedia Society
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• v.13 no.1
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• pp.1-9
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• 2010

Today's growth of the mobile communication infrastructure made mobile computing systems like cellular phones came next to or surpassed the desktop PCs in popularity due to their mobility. Although the performance of mobile devices is now being improved continuously, it is a current common sense that compute intensive large-scale applications can hardly run on any kind of mobile handset devices. To clear up this problem, we decided to exploit the mobile cluster computing system and surveyed the existing ones first. We found out, however, that most of them are not the actual implementations but a mobile cluster infrastructure proposal or idea suggestions for reliable mobile clustering. To make cell phones participated in cluster computing nodes, in this paper, we propose a redesigned JPVM cluster computing engine and a set of WIPI mobile runtime functions interfacing with it. And we also show the performance evaluation results of real parallel applications running on our Mobile-JPVM cluster computing systems. We find out by the performance evaluation that large-scale applications can sufficiently run on mobile devices such as cellular phones when using our mobile cluster computing engine.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.581-584
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• 2006

Cellular phones have been popularized and some of them even have access to the Internet. But the utilization of mobile phones has not been for education but only focused on particular services due to the text-based low capacity. This thesis proposes a multimedia education system using cell phones with SMIL. We can decrease the size of the parser and refute the resources of CPU by designing SMIL tag only, which is needed for multimedia education. In addition, the macro method for producing information for lectures will make possible decreased transmission quantity of multimedia contents and increased transmission efficiency. This will lead to overcoming the matter of insufficient CPU and memory, which is common to most mobile phone terminals.