• Spatial Information Research
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• v.15 no.2
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• pp.95-109
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• 2007

Recently people have been offered location based services on road networks. The navigation system, one of applications, serves to find the nearest gas station or guide divers to the shortest path based 2D map. However 3D map is more important media than 2D map to make sense friendly for the real. Although 3D map's data size is huge, portable devices' storage space is small. In this paper, we define continuous perspective queries to support 3D map to mobile user on road networks and propose this queries processing method.

• International journal of advanced smart convergence
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• v.5 no.3
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• pp.16-26
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• 2016

This proposed project is about a bicycle anti theft devised system which helps people protect the bicycle from theft and helps to track the stolen bicycle's location using a smart phone. Safety bike uses two main devices to keep the bicycle secured, the vibration sensor and GPS sensor. The purpose of this project is to put all these small devices into one well connected system which will help the bicycle owner have more control over the security of his own bicycle. The whole system can be divided into two main parts. The first part is about the hardware development whereby all electronics components are connected via the circuit design using wire wrapping technique. This hardware part includes, a vibrations sensor, a GPS receiver, a toggle switch, LED light, Bluetooth and a buzzer. Wireless Bluetooth signals are used as the means of communication between the smartphone and the microcontroller. The second part is the software part which is being to program and control the whole system. The program is written using MikroBasic, a full-featured Basic compiler for microcontroller based systems. In conclusion, this system is designed to enable user to have control in securing his/her bicycle also being able to find and locate it at any time using GPS receiver and mobile android application.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.1
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• pp.189-193
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• 2014

SNS (Social Network Service) has evolved to life-friendly service with the combination of local services. Unlike exsiting mobile services, life-friendly service is expected to be personalized with gathering of local information, location information and social network service information. In the process of gathering various kinds of information, Big-data technology and Cloud technology is needed. The effective algorithem has researched for this already, however the privacy protection model hasn't researched enough in life-friendly service or big-data using circumstance. In this paper, the privacy issue is dealt with in terms of 'Structure hole', and the privacy issue comes from big-data technology of life-friendly service.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.5
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• pp.73-79
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• 2011

With increasing use of smartphone, users require a new message service to prevent security attack and provide integrated messages. Since smartphone uses data services such as 3G cell network and WiFi, it can provide reliable message transfer through various security policies. In addition, it can transfer various data collected using built-in camera and GPS. This paper proposes a smart message service platform which can provide security services such as authentication, confidentiality and integrity as well as transfer the integrated message including location, picture and text. To verity the functionality of the platform, this paper implements an iPhone app and message transfer server, and then shows the implementation results.

• Proceedings of the KIEE Conference
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• 2006.04a
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• pp.318-320
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• 2006

Inaccurate localization exposes a robot to many dangerous conditions. It could make a robot be moved to wrong direction or damaged by collision with surrounding obstacles. There are numerous approaches to self-localization, and there are different modalities as well (vision, laser range finders, ultrasonic sonars). Since sensor information is generally uncertain and contains noise, there are many researches to reduce the noise. But, the correctness is limited because most researches are based on statistical approach. The goal of our research is to measure more exact robot location by matching between built VRML 3D model and real vision image. To determine the position of mobile robot, landmark-localitzation technique has been applied. Landmarks are any detectable structure in the physical environment. Some use vertical lines, others use specially designed markers, In this paper, specially designed markers are used as landmarks. Given known focal length and a single image of three landmarks it is possible to compute the angular separation between the lines of sight of the landmarks. The image-processing and neural network pattern matching techniques are employed to recognize landmarks placed in a robot working environment. After self-localization, the 2D scene of the vision is overlaid with the VRML scene.

• Journal of Korean Institute of Industrial Engineers
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• v.36 no.1
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• pp.52-58
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• 2010

The level of competition has reached the limits in cellular phone market and the cellular phone manufacture companies started to focus their solution in user interface. Design issues with controllability led the development and renovation of such products to the use of the touch-screen phone. Depending upon the readability, technical advances, portability and controllability, user satisfaction of touch-screen phones could vary significantly. In this research, the controllability was dealt in regard to various grip postures, in order to improve menu layout which fits for using the thumbs of both hands and a thumbs of single hand. Regression models are found to the suggest the location of buttons on the screen by redesigning the menu layout, it is expected to improve both controllability and satisfaction of the user. This result can be applicable not only to mobile phone design, but also to the design of various hand-held devices using a touch screen.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1298-1299
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• 2015

이동 로봇의 자기 위치 인식 방법으로 GPS를 많이 이용하지만 건물 내부공간에서는 위성신호 수신 장애가 있기 때문에 GPS 사용이 어렵다. 이에 대한 대안으로 다양한 형태의 실내 측위 기술에 관한 연구가 진행되어왔다. 최근에는 WiFi를 이용한 방법이 일부 상용화 되고 있으나 정밀도가 3~5m라는 한계가 있으며, LED 조명을 이용한 방법은 실용화 단계에 이르지는 못했지만 많은 연구가 진행되고 있다. 당 연구실에서도 LED조명을 기반으로 한 실내위치 인식 시스템을 개발하였으며, 지난 연구에서는 이를 이용한 이동로봇의 자율주행을 연구하였다. 본 연구에서는 지난 연구에 덧붙여 두개의 수신부를 이용하여 로봇의 방향인식오류 개선 및 이동 로봇의 자율주행을 보여주고자 한다. 제시된 시스템은 이동로봇, 조명제어장치 그리고 컴퓨터로 구성된다. 이동로봇은 상용화된 마이크로 마우스에 탑재된 조명신호 수신장치를 통하여 자신의 위치와 방향을 감지하며, 컴퓨터와의 Wi-Fi 통신으로 자신의 위치를 컴퓨터에 전송하거나 위치 명령을 수신한다. 컴퓨터에서는 수신 받은 이동로봇의 위치를 실시간으로 화면에 표시하며, 이동로봇에 전달할 위치명령을 사용자가 입력하는 기능을 제공한다. 사용자가 이동경로를 설정한 후 이동로봇으로 명령을 보내면 로봇은 자신의 위치와 목적지를 비교하며 자율주행을 하게 된다. 실험을 통하여 확인한 결과 지난연구의 방향인식의 문제점이 해결되어 제시된 시스템으로 실내공간에서도 이동로봇의 자율주행이 원만히 이루어짐을 확인하였다.

• The Journal of the Korea Contents Association
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• v.20 no.2
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• pp.114-126
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• 2020

With the growth of information technology, people consume online video contents via mobile phone without time and location constraints. Drawing upon uses and gratification theory, this study examines the effects of usage motives and affinity on user activities on YouTube. Specifically, user activities are subdivided into pre-viewing and during-viewing activities in this study. Results show that convenient entertainment and social interaction are the significant indicators for pre-viewing activities, whereas five different motives significantly influence during-viewing activities. Furthermore, affinity is the significant determinant of the both activities. The theoretical and practical implications are also discussed.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.5
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• pp.457-461
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• 2008

Previous studies on overlay ad hoc multi-casting are mainly divided into two categories: hierarchical structure-based multicast schemes and non-hierarchical structure-based multicast schemes. They do not reflect their real-time location information for routing updates. This can be a cause of low performance on energy consumption, throughput, and latency. For improving the problems, we propose an implicit cluster based overlay ad hoc multicast scheme with analysis of related work, and then we evaluate performance through computer simulation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.601-603
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• 2013

The nodes of Ad-hoc network are made up of location registration for sending informations and a great number of packet transmissions to maintain routing route among the nodes. Under this environment, a huge number of traffics would be generated as mobility variable occurs more than in physical network. Hence, in this paper, focused on to study the relationship of nodes to analyze the extent of the traffic in order to control the traffics of the multi-hop in Ad-hoc.