• Journal of Distribution Science
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• v.16 no.4
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• pp.67-74
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• 2018

Purpose - Most of the amendments to the law on the improvement of the distribution structure of mobile communication terminal equipment, the fully self-sufficient system of terminals, and the separated disclosure system on the terminals are aimed at securing transparency of the distribution structure by eliminating or reducing handset subsidies. This study investigates what items are important for the purchase of mobile phones in various and rapidly changing mobile phone markets from the consumer's point of view and tries to make a strategic suggestion for future mobile distribution strategies. Research design, data, and methodology - The procedure of this study takes place in four steps. In step 1, only the SF type respondents selected for this study were extracted through MBTI analysis. In step 2, they were divided into three hierarchies for the AHP analysis and each element was arranged. In step 3, the AHP analysis was converted to a Fuzzy-AHP number using the trigonometric centroid method. This was to eliminate the ambiguity of the response by converting into a fuzzy number even if data consistency was maintained with CI value below 0.1. In step 4, the number of converted 2-layer and 3-layer was combined to derive the priority when the final handset is selected. Results - First, the highest importance among the four items in the second tier was the terminal function item, followed by brand, price, and design item. Second, in the third tier, the highest importance was level of after-sales service, followed by device price, processing speed, ease of use, usefulness, and rate system. Third, the arithmetic average of the determinant of the fuzzy function showed that processing speed, ease of use and usefulness in the function item, level of after-sales service in the brand item, and device price in the price item were the five most important factors among 16 choice factors. Conclusions - First, there will be a change in the consumption patterns of consumers who have compared distributors and dealers to purchase handsets with more subsidies. Second, it is highly likely that people will purchase new handsets only when they need to change their devices because they can not receive subsidies by switching phone brands any more.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.9
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• pp.1612-1616
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• 2006

For map services in the mobile environment, it should be considered that resource restriction or the mobile device. on, if a map database dedicated to mobile services may not be developed, the spatial data extracted from general map databases should be simplified before transmitting. % is paper suggests the filtering methods to manipulate the spatial data, which are changed to be able to displayed on the mobile devices. The suggested methods are evaluated by experiments. This method is based on the map generalization operator 'selection' and is refined to adapt on mobile phone environments.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.464-467
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• 2003

There are two approaches to construct mobile GIS, Vector and Raster methods, according to the map data transformation format from server to mobile client. Each method requires a different implementation architecture of server and client modules for mobile map services. And each have advantages and disadvantages at the different aspects. This thesis implements these two approaches, thus, compares the each merits, by experiments. They include the transmission performance, map quality, and so on.

• Journal of the Optical Society of Korea
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• v.20 no.1
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• pp.150-155
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• 2016

To evaluate the autofocusing performance of recent mobile phone cameras, it is necessary to determine the peak position of the center field MTF (Modulation Transfer Function), -known as the through focus MTF- of the module. However, the MTF peak position found by conventional methods deviates from the ideal position due to the focus scanning resolution of mobile phone cameras. This inaccurate peak position results in false judgements of the optical performance, leading to yield losses or customer complaints. An increase in the focus scanning resolution can address this problem, but the manufacturing UPH (Unit per Hour) level will also unfortunately increase as well, resulting in a loss of manufacturing capabilities. In this paper, several fitting models are studied to find an accurate MTF peak position within a short period of time. With an analysis of a large amount of manufacturing data, it is demonstrated that the fitting methods can reduce false judgements and simultaneously increase the capabilities of the manufacturing system.

• Korean Journal of Digital Imaging in Medicine
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• v.12 no.1
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• pp.1-4
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• 2010

The study was designed to transmit ECG(electrocardiogram) images from iPhone in order to check validity. Especially, web examined ECG transmissions from smart phones image viewer are good enough to secure clinical information and confirmed with visual. In result, it took 3 to 5 seconds for ECG viewer transmitting from a smart phone to display an image on mobile server to user's phone. For image valuation, we magnified the ECG image 100% or 200% at a resolution of $480{\times}320$ checking PQRST wave and found that it was both possible to see an accurate PQRST wave with all the trial data and to divide it into 1mm level of grid.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.1
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• pp.57-65
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• 2012

People leave voicemails or record phone conversations in their daily cell phone use. Sometimes important voice data is deleted by the user accidently, or purposely to cover up criminal activity. In these cases, deleted voice data must be able to be recovered for forensics, since the voice data can be used as evidence in a criminal case. Because cell phones store data that is easily fragmented in flash memory, voice data recovery is very difficult. However, if there are identifiable patterns for the deleted voice data, we can recover a significant amount of it by researching images of it. There are several types of voice data, such as QCP, AMR, MP4, etc.. This study researches the data recovery solutions for EVRC codec and AMR codec in QCP file, Qualcumm's voice data format in cell phone.

• The Journal of Bigdata
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• v.5 no.2
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• pp.85-95
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• 2020

In this study, a mobility analysis method is suggested to estimate an O/D trip demand estimation using Mobile Phone Signaling Data. Using mobile data based on mobile base station location information, a trip chain database was established for each person and daily traffic patterns were analyzed. In addition, a new algorithm was developed to determine the traffic characteristics of their mobilities. To correct the ping pong handover problem of communication data itself, the methodology was developed and the criteria for stay time was set to distinguish pass by between stay within the influence area. The big-data based method is applied to analyze the mobility pattern in inter-regional trip and intra-regional trip in both of an urban area and a rural city. When comparing it with the results with traditional methods, it seems that the new methodology has a possibility to be applied to the national survey projects in the future.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.23 no.4
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• pp.77-93
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• 2024

The recent development of data collection technology, which conveys various travel data in real-world such as mobile data and probe vehicle data, facilitates transportation planners identifying specified spatio-temporal travel patterns. In this study, an easily implementable travel mode classification methodology was proposed to classify inter-regional trip-modes without modeling by superimposing trajectories generated from mobile phone signaling and transportation infrastructure points into a polygon scale of a shapefile in a GIS system. Each regional mode trip was classified according to the rules such as the presence of transportation infrastructure in the trip trajectory, travel time, and the presence of access trips. An accuracy test generates Type I and Type II error results table to verify the proposed methodology. As a result, it was found that the methodology developed showed the F1-Score of the air mode 1.00, rail mode 0.95, bus mode 0.73.

• The Journal of Society for e-Business Studies
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• v.15 no.2
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• pp.1-18
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• 2010

Mobile Communication Companies are trying to increase data services rather than telephone communication services that already became saturated as the competition of mobile communication market gets intensified. However, it is hard and time-consuming for customers to find desired mobile phone wireless services because of the limitation of screen and speed of the mobile phone. Therefore, the market does not grow rapidly as mobile communication companies expected. In our research, we suggest a personalized wireless service recommendation system that considers each individual context by using geographic information and wireless internet usage logs to overcome the mentioned problems. In order to design and implement the system, we conducted clustering analysis on base stations and real service usage logs of each base station, and suggested a personalized recommendation system based on collaborative filtering that uses the clustering results. Moreover, we verified the performances of our system with experiments.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.2
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• pp.171-179
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• 2011

In these days, various wireless internet services are possible since the advanced wireless networks enable to transfer more data than before and smarter devices have developed to display the multimedia information more efficiently. Therefore, Korean MIPS such as SKT and LGT provide many kinds of advanced services such as wireless on-line shopping, mobile banking system and etc using 2.5 generation wireless network technology and smartcards. In a transportation system, a cellular phone can be used as a useful payment tool since most people always keep it and a mobile payment system has developed as infrastructure for wireless on-line services. In this paper, a mobile transportation payment system is introduced. A driver needs to pay a toll fee when he/she uses the highways. Recently, a high pass system has introduced, in which a vehicle can pass a toll gate without stopping to pay the fee to a counter. The payment is done automatically by an attached payment device. We have developed an advanced mobile system in which a smartcard embedded cellular phone is used as a payment device. The personnel and financial information is stored at a smartcard and the communication between the phone and OBU(On Board Unit) is done by Bluetooth.