• 한국멀티미디어학회논문지
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• 제23권12호
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• pp.1507-1518
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• 2020

Recently, as the proportion of the elderly population in Korea has increased rapidly, it has entered an aging society. As the scope of social activities of the elderly increases, the risk of safety accidents is also increasing. The traffic accident rate of elderly pedestrians is higher than ordinary people. Although various smart devices for the elderly are researched and developed, electronic components are often used. Electronic devices may not be able to be used if charging is not regularly. In this paper, a smart hat, a smart system for the elderly and the weak, was implemented using solar panels. The system uses solar energy to provide reliable use of smart devices. It is believed to be helpful not only for the elderly but also for the weak people by easy to wear the hat.

• 한국멀티미디어학회논문지
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• 제7권12호
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• pp.1754-1764
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• 2004

Lately mobile handheld devices such as Personal Digital Assistant (PDA) and cellular phones are getting more popular for personal web surfing. However, today most mobile handheld devices have relatively poor web browsing capability due to their low performance so their users have to suffer longer communication latency than those of desktop Personal Computers (PCs). In this paper, we propose an effective pre-refresh mechanism for embedded web browser of mobile handheld devices to reduce this problem. The proposed mechanism uses the idle time to pre-refresh the expired web objects in an embedded web browser's cache memory. It increases the utilization of Central Processing Unit (CPU) power and network bandwidth during the idle time and consequently reduces the client's latency and web browsing cost. An experiment was done using a simulator designed by us to evaluate the efficacy of the proposed mechanism. The experiment result demonstrates that it has a good performance to make web surfing faster.

• Journal of Multimedia Information System
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• 제2권2호
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• pp.223-232
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• 2015

In this system, mobile devices are not independent, they can communicate with each other, one device's change can affect the whole system or other devices. To achieve the above mentioned A Self-Reconfigurable System of Contents, through discover the device and connect process, to establish the connection between the mobile devices. After user assigns two dimension display type, the user can select content to input the system, contents are portioning and broadcast to devices. The system can self-reconfigure contents rapidly and exactly. This technique supports contents self-reconfiguration for devices remove, addition and position exchange. In this paper, when the user uses the hand contacts device, the device sends a signal to assist the system to detection device's position. The system does not need to get accurate devices moving direction, just according to all changed devices position to judge where the devices destination is. This research develops an application according to this technique, and the real machine tests the application using Android platform. Some communication protocols and mathematical modeling methods are proposed. These methods can also be used in other Internet of Things (IoT) fields, such as Drones Navigation, Smart Home, and Informational City management.

• 한국정보통신학회논문지
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• 제24권11호
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• pp.1463-1469
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• 2020

동영상이나 음성을 포함하는 멀티미디어 정보는 사람들이 쉽게 이해 가능하다는 점에서 활용도가 높다. 이러한 이유로 멀티미디어 정보를 저장한 IoT 장치가 스마트폰과 연동하여 정보를 전달하는 응용들이 연구되었다. 문제는 동영상이나 이미지 등으로 인해 정보의 크기가 IoT장치의 용량보다 커질 수 있다는 것이다. 본 논문에서는 IoT 장치처럼 저장용량에 한계가 있는 경우, 저장 용량의 한계를 고려한 멀티미디어 콘텐츠 설계 기법을 연구하였다. 동영상이 문자보다 정보 이해도가 높은 반면 용량은 크다는 점을 고려하여 정보 이해도와 용량 간의 해법을 구하는 것이다. 정적미디어와 동적미디어의 크기를 변수로 하고 선형 계획법에 의거하여 해를 풀이한다. 사례 연구를 통하여 본 논문의 설계기법이 유용함을 보였다.

• International Journal of Contents
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• 제13권1호
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• pp.53-61
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• 2017

Recently, the Social Internet of Things (IoT), the follow-up of the IoT, has been studied to expand the existing IoT services, by integrating devices into the social network of people. In the Social IoT environment, humans, devices and digital contents are connected with social relationships, to guarantee the network navigability and establish levels of trustworthiness. However, this environment handles massive data, including social data of humans (e.g., profile, interest and relationship), profiles of IoT devices, and digital contents. Hence, users and service providers in the Social IoT are exposed to arbitrary data when searching for specific information. A study about the recommender system for the Social IoT environment is therefore needed, to provide the required information only. In this paper, we propose the Social correlation group based Recommender System (SRS). The SRS generates a target group, depending on the social correlation of the service requirement. To generate the target group, we have designed an architecture, and proposed a procedure of the SRS based on features of social interest similarity and principles of the Collaborative Filtering and the Content-based Recommender System. With simulation results of the target scenario, we present the possibility of the SRS to be adapted to various Social IoT services.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권10호
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• pp.4948-4967
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• 2017

On mobile devices, image sequences are widely used for multimedia applications such as computer vision, video enhancement, and augmented reality. However, the real-time processing of mobile devices is still a challenge because of constraints and demands for higher resolution images. Recently, heterogeneous computing methods that utilize both a central processing unit (CPU) and a graphics processing unit (GPU) have been researched to accelerate the image sequence processing. This paper deals with various optimizing techniques such as parallel processing by the CPU and GPU, distributed processing on the CPU, frame buffer object, and double buffering for parallel and/or distributed tasks. Using the optimizing techniques both individually and combined, several heterogeneous computing structures were implemented and their effectiveness were analyzed. The experimental results show that the heterogeneous computing facilitates executions up to 3.5 times faster than CPU-only processing.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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• pp.256-259
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• 2004

Recently, Location-based services(LBS) allow consumers to receive services based on their geographic location data. Users want to take services based location information with portable devices. And Point of Interest(POI) information's usage is increasing with mobile device's development and user's interest. And this paper shows that we connect the multimedia POI database(DB), provide the multimedia services through the portable devices and search POI using location and direction information. The multimedia POI is consisted of sound, image, moving image and animation with location information. When we search POI, we find POI in DB using the area zone and direction information.[l]

• 대한임베디드공학회논문지
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• 제2권1호
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• pp.1-8
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• 2007

In this paper, we developed a file system architecture for portable multimedia devices. To enhance user convenience, the information about the stored files should be easily retrieved and organized. We defined NMD (Networked MetaData), which can organize the files in networked fashion by attaching user-defined attributes and relation between files. The NMD is stored in flash memory to utilize its nonvolatile property and low-power consumption, while multimedia files are stored in hard disk, an inexpensive mass storage. The experimental implementation showed that this architecture was able to save about 10% power compared to the hard disk NMD-store.

• 한국멀티미디어학회논문지
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• 제20권11호
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• pp.1842-1848
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• 2017

Recently, user motion estimation methods using various wearable devices have been actively studied. In this paper, we propose a motion estimation system using Myo, which is one of the wearable devices, using two Myo and their dependency relations. The estimated motion is used as a command for remotely controlling the robot. Myo's Orientation and EMG signals are used for motion estimation. These two type data sets are used complementarily to increase the accuracy of motion estimation. We design and implement the system according to the proposed method and analyze the results through experiments. As a result of comparison with previous studies, the accuracy of motion estimation can be improved by about 12.3%.

• 한국멀티미디어학회논문지
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• 제23권12호
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• pp.1531-1539
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• 2020

Searching for portable baggage through the system before boarding an airplane at an airport is important because it prevents many risks. In addition to these dangerous items, personal and confidential information leaks are occurring at airports through data storage devices. In the airport search system, there is a need for a system that searches not only dangerous items but also devices that can leak data. In this paper, we proposed a model that searches for a data storage device by improving the existing model. A comparative evaluation was conducted using existing algorithms. As a result, it was confirmed that the performance of the proposed model is 74 in the training data and 46.73 in the test data, which is superior to the existing model.