• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.2
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• pp.35-46
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• 2013

As a rapid increase of mobile network usage, many studies on solution for network traffic's demand problem have been done. Especially network environment measurement area provides basis for solving network traffic's demand problem by finding causes of problems through accurate network analysis. However, as increase of demand for smartphone, we should consider effects of mobile platform's property measuring mobile network. In this paper, we design a network traffic measurement system considering mobile platform. Through the information from packets, this system calculates packet transmission delay and throughput. We minimize computation cost required for a mobile device that is a client in this system. When fully using network resources, we found that Wi-Fi has shorter transmission delay, higher maximum throughput and lower loss rate than 3G, Android has shorter transmission delay and higher maximum throughput than iOS, and UDP has longer transmission delay and higher maximum throughput through this system.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.163-163
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• 2009

Viewing angle controllable liquid crystal display (LCD) associated with fringe-field switching (FFS) mode with high image quality is proposed. In the device, one pixel is composed of main and sub pixels, in which adjacent sub pixel is patterned with pixel electrodes direction orthogonal to the adjacent one. In this way, light leakage can be generated in the all viewing angle directions except the normal direction, realizing view angle controllable LCD in both horizontal and vertical directions.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.275-278
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• 1998

In recent years, miniaturization has become the key factor in the development of mobile communication system. Portable communications and computing devices suffer from two conflicting requirements which are device size to be as small as possible and large, high resolution display. These problems can be solved by virtual display. Any display in which the user views an image through an optical system is a virtual display. It provides a display which is high resolution, appears large to the viewer and at the same time occupies little physical space. In this study, handhold units of mobile communication was investigated through use of the SLA(Scanned Linear Array). The basic SLA mechanism comprises a linear array of LED's, a magnifying lens, and a scan mirror. To optimize virtual image, we investigated optical system design and operating condition for each part.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.5
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• pp.1173-1180
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• 2012

Based on Smart Phone, this study added and implemented the mobile App to the existing IT agriculture system, which system automatically controlled green house's growth environment. Because the mobile App characterfully possesses high portability, limited resource, mobile wireless network support, enterprise mobile computing support, etc., the hybrid-App should be inevitably adopted. The hybrid App can minimize resource consumption for performing related duties and also, in spite of the mobile device's limits, it can derive high performance, in which facts the system can ensure the service-based architecture's reliance and also, implements the highly sophisticated functionality as well. Through the proposed system, the study expects to contribute to improve quality of life as well as to increase farmer's income through IT-based agriculture system development.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.2 s.332
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• pp.1-8
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• 2005

We have implemented a Jini-Agent system which enables resource-limited mobile devices to utilize the Jini connection service. The Jini-Agent system supports Jini connection technologies to mobile devices without additional client program installation in it. It also supports a dynamic service list which helps the mobile devices to search and to utilize the services through web browser in real time. A couple of examples such as a file search service and a print service with mobile devices have been demonstrated by using the Jini-Agent system.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.1
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• pp.54-60
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• 2021

AR (Augmented Reality) is a technology that provides virtual content to the real world and provides additional information to objects in real-time through 3D content. In the past, a high-performance device was required to experience AR, but it was possible to implement AR more easily by improving mobile performance and mounting various sensors such as ToF (Time-of-Flight). Also, the importance of mobile augmented reality is growing with the commercialization of high-speed wireless Internet such as 5G. Thus, this paper proposes a system that can provide AR services via GNN (Graph Neural Network) using cameras and sensors on mobile devices. ToF of mobile devices is used to capture depth maps. A 3D point cloud was created using RGB images to distinguish specific colors of objects. Point clouds created with RGB images and Depth Map perform downsampling for smooth communication between mobile and server. Point clouds sent to the server are used for 3D object detection. The detection process determines the class of objects and uses one point in the 3D bounding box as an anchor point. AR contents are provided through app and web through class and anchor of the detected object.

• Proceedings of the IEEK Conference
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• 2000.11b
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• pp.249-252
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• 2000

A new Smart rower IC's based on the Partial SOI technology was designed for such applications as mobile communication systems, high-speed HDD systems etc. A new methodology of integrating a 0.8${\mu}{\textrm}{m}$ BiCMOS compatible Smart Power technology, high voltage bipolar device, high speed SAVEN bipolar device, LDD NMOSFET and a new LDMOSFET based on the Partial SOI technology is presented in this paper. The high voltage bipolar device has a breakdown voltage of 40V for the output stage of analog circuit. The optimized Partial SOI LDMOSFET has an off-state breakdown voltage of 75 V and a specific on- resistance of 0.249mΩ.$\textrm{cm}^2$ with the drift region length of 3.5${\mu}{\textrm}{m}$. The high-speed SAVEN bipolar device shows cut-off frequency of about 21㎓. The simulator DIOS and DESSIS has been used to get these results.

• Journal of Korea Society of Digital Industry and Information Management
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• v.11 no.3
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• pp.11-19
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• 2015

Due to recent development in mobile devices, the mobile device utilization and many related applications have been increasing. Most of initial applications on mobile devices just showed simple information, but now they processes huge data. However, smart devices have certain limitations in processing massive data. Especially, if the size of data increases, the speed of data processing adversely decreases, so the performance of programs also decreases. If hardware specification of the mobile devices is not enough to handle it, response time will be drastically delayed. To overcome these drawbacks, most of application running on mobile devices communicate with their servers to manage data. XML is a proper language for data communication to send and receive data between servers and mobile devices, because it defines rules of document's format and it is a textual data format and small-sized language. However, mobile devices have limitation such as memory, CPU and wireless network to process huge data and XML also takes a lot of time to communicate with servers and devices and handle data, so it could be overhead in service time. Binary XML is an alternative of performance improvement in data processing, which has XML's benefits and minimizes the XML size by binary coding. However, most of binaryXML which are used on applications don't fit on mobile applications. In this paper, we surveyed many kinds of binaryXML, compared merits and demerits to find a binaryXML for mobile applications. We propose how to use binary XML and implemented an electronic attendance system using binary XML to overcome the limitation of XML and to reduce the load of data communications between servers and devices.

• Journal of Sensor Science and Technology
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• v.23 no.3
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• pp.149-157
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• 2014

This paper considers the ability of counting and positioning multi-targets by using a mobile UWB radar device. After a background subtraction process, distinguishing between clutters and human body signals, the position of targets will be computed using weighted Gaussian mixture methods. While computer vision offers many advantages, it has limited performance in poor visibility conditions (e.g., at night, haze, fog or smoke). UWB radar can provide a complementary technology for detecting and tracking humans, particularly in poor visibility or through-wall conditions. As we know, for 2D measurement, one method is the use of at least two receiver antennas. Another method is the use of one mobile radar receiver. This paper tried to investigate the position detection of the stationary human body using the movement of one UWB radar module.

• Journal of Sensor Science and Technology
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• v.31 no.5
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• pp.286-292
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• 2022

As mobile electronics become smarter, higher-level security systems are necessary to protect private information and property from hackers. For this, biometric authentication systems have been widely studied, where the recognition of unique biological traits of an individual, such as the face, iris, fingerprint, and voice, is required to operate the device. Among them, ultrasound fingerprint imaging technology using piezoelectric materials is one of the most promising approaches adopted by Samsung Galaxy smartphones. In this review, we summarize the recent progress on piezoelectric ultrasound micro-electro-mechanical systems (MEMS) transducers with various piezoelectric materials and provide insights to achieve the highest-level biometric authentication system for mobile electronics.