• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.1
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• pp.25-30
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• 2008

In this paper, we propose a color quantization method regarding facial image for mobile services. For facial images, skin colors are more emphasized. First, we extract skin-color mask in the image and divide the image into two regions. Next, we extract color pallette for two regions respectively. In the proposed method, the loss in the face region is minimized and it can be useful for mobile services considering facial images. From the 8-bit color quantization experiment, we show that the proposed method works well.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.9
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• pp.4301-4319
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• 2017

Adopting mobile chargers (MC) in rechargeable wireless sensors network (R-WSN) to recharge sensors can increase network efficiency (e.g., reduce MC travel distance per tour, reduce MC effort, and prolong WSN lifetime). In this study, we propose a mechanism to split the sensing field into partitions that may be equally spaced but differ in distance to the base station. Moreover, we focus on minimizing the MC effort by providing a new charging mechanism called the sector-based charging schedule (SBCS), which works to dispatch the MC in charging trips to the sector that sends many charging requests and suggesting an efficient sensor-charging algorithm. Specifically, we first utilize the high ability of the BS to divide the R-WSN field into sectors then it select the cluster head for each sector to reduce the intra-node communication. Second, we formulate the charging productivity as NP-hard problem and then conduct experimental simulations to evaluate the performance of the proposed mechanism. An extensive comparison is performed with other mechanisms. Experimental results demonstrate that the SBCS mechanism can prolong the lifetime of R-WSNs by increasing the charging productivity about 20% and reducing the MC effort by about 30%.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.142-146
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• 2014

The mobile computing has been a main mean of computing, because of recent development of smartphone and mobile communication network. The new service technologies, such as cloud computing, big data, SDN (Software Defined Network), and NFV (Network Function Virtualization), are appearing due to activating of the data center. These changes have brought various requirements for transport layer protocol. In addition, the transport protocol should have a extensible function to adapt additional technologies. This paper proposed that transport layer divide into three layer structure for extensible function, and designed the ETP(Extensible Transport Protocol) which is located in the bottom layer.

• 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 rehabilitation welfare engineering & assistive technology
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• v.9 no.1
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• pp.23-28
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• 2015

This study is to investigate the accessibility compliance status of smart devices for people with disabilities in the information age, smart and offer improvements. Vision of smart devices, operating systems (IOS, Android, Windows) based smart devices currently in use by most, hearing, investigation and provide handicapped accessibility status and improvement measures derived from a comparative analysis of the Disabled Accessibility Improvement of smart devices was presented.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.364-367
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• 2009

This paper presents a scheme that generates a caption file by extracting a Closed Caption stream from DTV signal. Note that Closed-Captioning service helps to bridge "digital divide" through extending broadcasting accessibility of a neglected class such as hearing-impaired person and foreigner. In Korea, DTV Closed Captioning standard was developed in June 2007, and Closed Captioning service should be supported by an enforcing law in all broadcasting services in 2008. In this paper, we describe the method of extracting a caption data from MPEG-2 Transport Stream of ATSC-based digital TV signal and generating a caption file (SAMI and SRT) using the extracted caption data and time information. Experimental results verify the feasibility of a generated caption file using a PC-based media player which is widely used in multimedia service.

• Journal of the Semiconductor & Display Technology
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• v.14 no.4
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• pp.92-97
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• 2015

The purpose of this work is to support a solution of optimizing TMO (tone mapping operator). JPEG XT Profile A and C utilize Erik Reinhard TMO that works well in most cases, however, detailed information of a scene is lost in some cases. Reinhard TMO only calculates its coefficient to have tone-mapping curve from log-average luminance, and this lead to lose details of bright and dark area of scenes in turn. Thus, this paper proposes an enhancement of the default TMO for JPEG XT Profile C to optimize tone-mapping curve. Main idea is that we divide tone mapping curve into several ranges, and set reasonable parameters for each range. By the experimental results, the proposed scheme shows and obtains better performance within a dark scene, compared to the default Reinhard TMO.

• Journal of the Semiconductor & Display Technology
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• v.15 no.1
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• pp.33-35
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• 2016

This paper proposes a method utilizing image compression and transmission method for image segmentation in order to reduce the time required in the process of analyzing the image information that has in the image compression process. Many studies of existing with respect to the image segmentation are being studied as a way to split a lot of a particular part in the image. We divide full image into the N equal parts. And it is compressed using the field coding. This will reduce the time-consuming than using the conventional method.

• 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 Korea Institute of Information Security & Cryptology
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• v.13 no.4
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• pp.109-127
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• 2003

In this paper, we analyze the network architecture, authentication, and key agreement of GSM and UMTS to compare the handover between the systems. And then, we divide authentication and key agreement procedure of mobile subscribers into several cases and finally analyze the key agreement procedure when a handover occurs in a CS-Domain and a PS-Domain.