• Proceedings of the Korea Information Processing Society Conference
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• 2016.04a
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• pp.897-899
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• 2016

In recent years, BLE technology has received extensive attention and has been applied to all aspects of life. The existing BLE device has two methods, one is the connection method, and the other is a non-connection method. The representative profile of the connection method is the proximity file. The most typical example of Non-connection method BLE device is a beacon. However, they are both independent and have their own shortcomings. Connection method device can provide service for only one user, others can't use. Security performance of Non-connection method BLE device is poor and the device can't be controlled by the user. In this paper, a combination-mode BLE device profile design scheme is presented, which combines with the previous two methods, and solves the defaults. And We define a dual purpose advertising package that can be used in a normal environment as well as in a disaster environment. Finally, a unidirectional Control idea is proposed. Through performance evaluation, we found that the device has strong stability and low power consumption.

• The Journal of the Korea Contents Association
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• v.15 no.5
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• pp.27-35
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• 2015

Depending on the smart device user growth and development of communication technology, the area about working environment was extended without constraints of time and places. It is introducing to work using user's devices and this environment is called 'BYOD(Bring Your On Device)'. But it is vulnerable to security threat that happened in existing wireless environment and its security threat issue which is caused by inside information leak by an inside job and lost or stolen terminal which is caused by careless user is getting heated. So we studied about access control protocol by user rights under the BYOD situation make a session key based on the user information. We make a session key based on the user information and user device information, after that we design an access control protocol. The protocol we suggest can protect from attack under the BYOD situation and wireless communication situation and also safety and security requirement from inside information leak because it controls user rights.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.6
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• pp.36-42
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• 2009

In the mobile device environment, the context-aware computing has been emerging as a core technology of ubiquitous computing. Compared with a desktop computer, a user interface and resource of mobile device is very limited. Traditional desktop-based user interface has been developed on the basis that a user's activity is static state. In contrast, mobile devices are not able to utilize representative desktop-based interaction mechanisms such as a keyboard and mouse, not only because the activity of a user is dynamic state, but mobile devices have limited resources and small LCD display. In this paper, we introduce an intelligent control system for the mobile device that can utility effectively the limited resource and complement the poor user interface by using an accelerometer being able to sense the physical activity and posture. The proposed system can estimate the user activity, static and dynamic states, and posture watching the PDA at the same time, and the proposed intelligent control system as its application, the backlight ON/OFF on the PDA, is run by the result of the user's behavior.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.1
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• pp.55-61
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• 2011

In this paper, the outage probability of device-to-device (D2D) uplink communication underlaying cellular networks is analyzed over Rayleigh fading. We assume that a D2D pair and M cellular user equipments share the same frequency resources. To prevent any harmful interference from a D2D transmitter to the BS, the maximum transmit power of the D2D transmitter is strictly limited. Under these assumptions, the outage probability is represented as a function of the interference-to-signal ratio from M cellular user equipments to a D2D receiver and the number of cellular user equipments, M. In addition, the interference-to-signal ratio is represented as a function of distances among D2D equipments, cellular user equipments and the BS. Simulation results validate these analytical results.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.2
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• pp.9-16
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• 2012

In this paper, the beamforming and user scheduling scheme for device-to-device (D2D) underlaying celullar networks with partial channel state information is investigated. In the proposed scheme, cellular users whose channels are nearly orthogonal to the channel between base station and D2D receiver are selected for unitary beamforming so as to minimize the interference to the D2D receiver. The interference caused by underlaying D2D communication can be minimized by reducing the D2D transmitter's transmission power. To enhance the cellular users' throughput further, we also investigate codebook generation method in which each code vector belongs to multiple unitary code matrices. From simulation results, we show that the proposed beamforming and user scheduling scheme mitigates D2D interference to the cellular networks and the codebook generation method improves cellular users' throughput.

• Journal of the Ergonomics Society of Korea
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• v.35 no.6
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• pp.519-533
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• 2016

Objective: This study lays its aims at the definition of relevant operation method and function by researching on the value to be brought when applying smart device that can hand carry soft and flexible materials like jelly. Background: New technology and material play a role in bringing type transformation of interface and change of operation system. Recently, importance has been increased on the study of Organic User Interface (OUI) that conducts research on the value of new method of input and output adopting soft and flexible materials for various instruments. Method: For fulfillment of the study, 27 kinds of gestures have been defined that are usable in handheld device based on existing studies. Quantitative research of survey was conducted of adult male and female of 20s through 30s and an analysis was done on the function that can be linked to gestures with highest level of satisfaction. In order to analyze needs and hurdles of users for the defined gesture, a focus group interview was conducted aiming at the groups of early adopters and ordinary users. Results: As a result, it was found that users have much value regarding usability and fun for elastic device and analysis could be conducted on preferred gesture and its linkable functions. Conclusion: What is most significant with this study is that it sheds new light on the values of a device made of elastic material. Beyond finding and defining the gestures and functions that can be applied to a handheld elastic device, the present study identified the value elements of an elastic device - 'usability and 'fun' -, which users can basically desire from using it. Application: The data that this study brought forth through preference and satisfaction test with the gestures and associated functions will help commercialize an elastic device in future.

• The KIPS Transactions:PartC
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• v.15C no.5
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• pp.343-350
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• 2008

In ubiquitous environment, a user has been provided with service and mobility using various devices. The users' network can be divided into a home network (a user belongs to the network through an authentication server) and an external network (when a user moves or external authentication server is). Users can use a mobile device or a device at an external network. In this paper, when a user has access to a service in an external network with a mobile device, there is a skim that a service is securely provided by roaming private information (encryption key etc${\cdots}$) and a skim which gives access to a home network using a device in an external network. If you use these skims, roaming is provided in order that you can use a secure service in an external network.

• 한국HCI학회:학술대회논문집
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• 2007.02b
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• pp.512-517
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• 2007

다양한 디지털 가전제품을 제조하는 회사들은 초기에 제품 하나하나에 제품의 사용경험을 담는데 비중을 높여 개발을 하였다. 하지만 제품이 알려지고 종류가 많아지면서 각 제품들을 아우르는 사용자 경험요소 통합화가 필요하게 되었다. 이에 다양한 화면 사이즈와 Input Device를 가진 Handheld Device들 간의 일관된 사용 경험(user experiences)을 제공하는 것을 목적으로 하는 연구가 진행되었다. 대상이 된 제품들은 Digital Media Broadcasting의 수신, Multimedia 파일이 재생, 파일 creation 등이 가능한 Handheld Devices였고, 각 제품들은 특정 기능에 충실한 UI를 구현하고 있다는 특징이 있다. 따라서, 기존 제품의 사용성을 저해하지 않는 수준의 표준화가 필요하며 기존 UI 사용성과 표준화 UI 사용성 간의 조화가 중요 하였다. 기존 제품의 개별 특징을 분석하고 Handheld Device의 사용자 요구사항을 조사를 통해 사용경험 요소를 발굴하고 Navigation, Menu Hierarchy, Screen Layout 등의 설계를 통해 Prototype 개발을 하고 Usability Test를 통해 보완을 하였다. Usability Test는 한국, 미국, 영국, 중국 4개국에서 광범위한 사용자 조사가 이루어졌다. 국가 선정은 제품의 주요 시장 및 각 대륙을 대표하는 기준으로 선정되었다. 사용자 그룹은 연령, 지식 수준, 성별에 구분되었고 Web Survey 1000명, Usability Test는 각 국가별 총 100명이 넘는 참석자에 의한 데이터 분석이 이루어 졌다. 이렇게 조사된 데이터를 바탕으로 UI 사용경험 요소를 정의하고 제품의 공통 가이드와 개별 가이드를 개발하는 일련의 프로세스를 확립하고 검증하였다. 본 논문을 통해 대상 제품들의 다양한 특성을 살리면서도 user Interface의 일관성 원칙을 설립하기 위해 시도했던 방법과 과정을 기술하고, 이 과정을 통해서 얻은 결과와 실제적인 경험을 소개한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.617-618
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• 2017

Recently, IoT can provide a service considering user's convenience by configuring the inside of the home as a smart environment. However, the existing system can not change the configuration of the home smart environment by the user, and there is a problem in compatibility between the server and the heterogeneous device. In this paper, we propose a system to reconfigure the relationship between the device and the server in the smart home environment to solve that. In a smart home environment, The user can add and delete devices through the application. In addition, when a new device is added, the server searches the schema for the device and establishes an automatic relationship. This makes it possible for the user to easily change the configuration of the smart home environment.

• ETRI Journal
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• v.29 no.3
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• pp.305-310
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• 2007

If a virtual object in a virtual environment represented by a stereo vision system could be touched by a user with some tactile feeling on his/her fingertip, the sense of reality would be heightened. To create a visual impression as if the user were directly pointing to a desired point on a virtual object with his/her own finger, we need to align virtual space coordinates and physical space coordinates. Also, if there is no tactile feeling when the user touches a virtual object, the virtual object would seem to be a ghost. Therefore, a haptic interface device is required to give some tactile sensation to the user. We have constructed such a human-computer interaction system in the form of a simple virtual reality game using a stereo vision system, a vibro-tactile device module, and two position/orientation sensors.