• Proceedings of the IEEK Conference
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• 2009.05a
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• pp.344-346
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• 2009

Cell type packaging line is more suitable for the products with various models and small quantities like mobile phone or mp3 player than conveyor type packaging line. Cell type packaging line is applicable to package various product models, but it can cause wrong product compositions and missing of items. So, automatic missing item detection system is needed. We designed an missing item detection system with a bar code reader, infrared sensors, and s digital camera. and also developed the programs for sensor data acquisition, image data processing, GUI, and data management.

• 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.

• Child Studies in Asia-Pacific Contexts
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• v.3 no.2
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• pp.81-103
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• 2013

This study explored social media use among 50 adolescents attending a public high school in a non-Western community. Adolescents participated in focus group interviews and completed a written self-report survey. Findings revealed that these teenagers use electronic communication forms such as phone texting and social networking sites to connect with friends and family. They show a preference for Facebook, YouTube, and Instagram, do not engage in risky Internet behavior, and acknowledge both positive and negative aspects of electronic communication forms. In addition, their selection of electronic communication forms is dependent upon several factors that include the strength of the relationship and type of discourse exchange. For example, they reserve phone texting and cell use, which are more private communication mediums for family and friends. Electronic communication did not replace face-to-face interactions; rather it complemented and extended those interactions. Findings support existing literature on adolescent social media use and those shared with other collectivist cultural groups.

• Journal of Korean Association for Spatial Structures
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• v.17 no.1
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• pp.93-100
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• 2017

With increasing number construction of high-rise building which has about 40 to 60 floors there have been many kinds of problem which related with usage from vibration. To predict response acceleration, it is important to assess correct natural frequency. However, due to the noise of MEMS sensor, it is difficult to measure dynamic characteristic such as natural frequency when measuring ambient vibration using MEMS sensor within cell phone. Therefore, a comparative analysis on vibration measuring applications was performed after measuring ambient vibration of 2 skyscrappers which have height between 133.5~244.3m that are located in Seoul and Observation tower using I-jishin APP with noise reduction function of MEMS sensor in order to verify the effectiveness of low noise type vibration measurement APP.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.10
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• pp.1567-1570
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• 2022

This paper, we presents a RF protection technique of antenna switch by improving the power handling capability in worst case environment mode for mobile phone applications without critical payment of circuit performances such as insertion loss, isolation and ACBV (AC breakdown voltage). By applying a additional capacitive path located in front of the antenna in cell-phone, it performs the effective reduction of input power in high voltage standing wave ratio (VSWR) condition. Under the all-path off condition which causes a high VSWR, it achieved 37.7dBm power handling level as high as 5.7dB compared to that of conventional one at 2GHz. In addition, insertion loss and isolation performances were 0.31dB and 42.72dB at 2 GHz, respectively which were almost similar to that of the conventional circuit. The proposed antenna switch was fabricated in 130nm CMOS SOI technology.

• Journal of Advanced Navigation Technology
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• v.12 no.6
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• pp.583-590
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• 2008

U-AD using Mobile RFID is service of new concept. It will be able to provide a service to the user by reading Tag information which is attach in the CDs, the books and medical supply etc. with cellular phone equipped with RFID device which is available for reading RFID tags. Applies like this service and when reacting Tag with RFID Readers of the cellular phone, the advertisement contents which is not the possibility of seeing fragmentarily in the outside develops the service which is the possibility with the cellular phone of seeing at real-time with aim. U-AD using Mobile RAD detail shows product information by cell phone, user exactly knows desire product and looks forward purchasing efficiently. Also advertiser benefit from U-AD using Mobile RFID since advertises effects of product sufficiently are increased. And then it expands demand on product.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.8
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• pp.1893-1900
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• 2015

The government has the responsibility to prevent abuses of monopoly and promote competition in order to maximize consumer welfare. The government should address the asymmetry in the information as much as possible and ensure consumer choice. The subsidy seems to reduce the burden on the consumer service charges and handset prices but it actually distorts the market through price discrimination. The government caused the principal-agent problem by neglecting their appropriate role to prevent distortion of the mobile telecom market. The money used as subsidy is part of excess profit and could be transferred to down the price of mobile phone and charges and it would become a benefit to consumers. Separate announcement of subsidies by Mobile Communications Terminal Distribution Structure Improvement Act is a little developed policy but it was not actually realized. The market price close to that from perfect competition structure is plausible, ultimately.

• Journal of Korean Clinical Health Science
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• v.5 no.4
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• pp.1015-1020
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• 2017

Purpose. Walking depends on the speed and type of shoe to be worn, and the degree of impact varies with the muscle used. In addition, the speed can be changed by moving objects and using objects when walking. This study analyzed the change of walking speed by applying various factors influencing walking. Methods. A total of 60 patients who had not undergone musculoskeletal diseases during the last 1 year were included. Shoe type was divided into slippers and shoe heels. Behavioral types were divided into bagging, books, and cell phone use. The walking speed was measured by the general walking, the middle walking, and the fast walking. The time was measured using a 10M linear distance test. The collected data were analyzed with SPSS program for independent samples t-test, one-way ANOVA. Results. There was a statistically significant difference according to the type of shoes when walking. Walking speed was slow in shoe heel. In addition, There was statistically significant difference according to type of behavior task at walking. Walking speed was slow in task type using mobile phone during walking. Conclusions. The walking speed were appeared difference in each type of shoe heel, using mobile phone.

• Journal of the Korean Society for Railway
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• v.19 no.5
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• pp.656-662
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• 2016

Based on time dependent location data of mobile phone users, users' ODs were produced after tracing their travel route and inducing their origins and destinations. System considered average signalizing frequency, which means that the longer the travel length is the more frequent the signal is. This is a home-based OD and is limited to the Seoul Metropolitan area. The OD matrix from the mobile phone data which was aggregated to the cell and transformed to the 'Dong' area, was compared to the KTDB OD. The results can be analyzed and it was determined that they are highly correlated because individual coefficients are 0.98 and 0.85, the former between the OD of this study and the KTDB Si/Gun/Gu unit area OD and the latter between the OD of this study and the Dong unit area KTDB OD.