• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.1C
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• pp.116-128
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• 2005

The low-cost REID system is expected to be widely used in the ubiquitous computing environment as an intelligent device. Although REID systems have several advantages, they may create new threats to users' privacy. In this paper, a traceable and unlinkable REID system called 'Fair EPC system' is proposed for low-cost RFID tags. The proposed system enables the protection of users' privacy from unwanted scanning, and it is traceable to the tag by authorized administrators when necessary. The proposed system has some advantages; (1) eliminating any danger of exposing users' information via tag tracking through the cooperation between readers or back-end databases, (2) enabling the tracking of real serial number of the tag only through the cooperation of authorized administrators using a cryptographic secret sharing scheme, and (3) providing the efficiency of the proposed system reduce the computational workloads of back-end databases.

• Journal of the Korea Society of Computer and Information
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• v.12 no.5
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• pp.83-92
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• 2007

In this paper, we present a design and implementation of three dimensional pointing device using Inertial Navigation System(INS) that acquires coordinates and location information without environmental dependancy. The INS measures coordinates based on the data from gyroscope and accelerometer and corrects the measured data from accelerometer using Kalman-Filter. In order to implement the idea of three dimensional pointing device, we choose a three dimensional Space-recognition mouse and use RFIC wireless communication to send a measured data to receiver for printing out the coordinate on display equipment. Based on INS and Kalman-Filter theoretical knowledge, we design and implement a three dimensional pointing device and verified the usability as an input device that can capture a human's move. also, we describe the applicability of this device in ubiquitous computing environment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.159-162
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• 2006

In ubiquitous computing environments, which can be connected to the networks any time any where, wearable computers frequently will be changed their network connection point. Therefore, the demand of the mobility support service becomes more important. The mobility support mechanism allows a wearable computer to continue the existing services without the modification for the network configuration of wearable computer even if wearable computer changes the network connection point during its moving. In this paper, we design the component based middlewear for the mobility supports of wearable computers, propose the method of the mobility support service. This method tunnels the existing data to wearable computer using Mobile IP protocol even if a wearable computer moves to other network after recomposing dynamically the mobility support component in wearable middlewear.

• The KIPS Transactions:PartC
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• v.18C no.3
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• pp.195-198
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• 2011

Recent expansion of the ubiquitous environment and improvement of the USN give lots of U-healthcare systems. In this paper, we design and implement a wireless ECG measurement system that can send ECG signals among the sensors and collector. It can also give almost the same precision as a hospital ECG system with mobility. The most important fact of the mobile ECG system is the signal data connectivity among the sensors and device such as signal cables or wires. we can eliminate the signal cable through the Zigbee sender and collector via implementing Zigbee-SD communication system that can receive the ECG signal data. We also implement ECG app software on the smart phone that can analyze and show the data results directly. It can give lots of mobility and usability under ubiquitous environment and would be a very efficient wireless ECG system for U-healthcare service.

• Journal of the Korea Convergence Society
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• v.10 no.2
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• pp.1-6
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• 2019

The proposed model is developed to minimize the loss of information in incomplete data including missing data. The first step is to transform the learning data to compensate for the loss information using the data extension technique. In this conversion process, the attribute values of the data are filled with binary or probability values in one-hot encoding. Next, this conversion data is input to the deep learning model, where the number of entries is not constant depending on the cardinality of each attribute. Then, the entry values of each attribute are assigned to the respective input nodes, and learning proceeds. This is different from existing learning models, and has an unusual structure in which arbitrary attribute values are distributedly input to multiple nodes in the input layer. In order to evaluate the learning performance of the proposed model, various experiments are performed on the missing data and it shows that it is superior in terms of performance. The proposed model will be useful as an algorithm to minimize the loss in the ubiquitous environment.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.19 no.4
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• pp.41-49
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• 2009

In ubiquitous sensor networks, sensor nodes can be compromised by an adversary since they are deployed in hostile environments. False sensing reports can be injected into the network through these compromised nodes, which may cause not only false alarms but also the depletion of limited energy resource in the network. In the security solutions for the filtering of false reports, the choice of a security threshold value which determines the security level is important. In the existing adaptive solutions, a newly determined threshold value is broadcasted to the whole nodes, so that extra energy resource may be consumed unnecessarily. In this paper, we propose an application of the recursive contract net protocol to determine the threshold value which can provide both energy efficiency and sufficient security level. To manage the network more efficiently, the network is hierarchically grouped, and the contract net protocol is applied to each group. Through the protocol, the threshold value determined by the base station using a fuzzy logic is applied only where the security attack occurs on.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.11
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• pp.1539-1545
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• 2020

With the advent of the ubiquitous era due to the development of science and technology in the modern society, interest in data generated in the IoT environment has increased socially. However, the existing IoT platform has difficulties in processing inquiry requests that require large amounts of throughput, such as statistical processing of large amounts of data. Accordingly, in this paper, we propose an IoT platform that can flexibly accommodate requirements for inquiry requests and improve inquiry performance. The platform proposed in this paper showed a performance improvement of about 1200 times in terms of average response time by introducing a separate read database. By separating the object model into a command side and a query side, the complexity of the object is reduced to meet the various demands on the platform. It was made to allow quick acceptance of the matter.

• 한국HCI학회:학술대회논문집
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• 2007.02b
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• pp.70-77
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• 2007

모바일 IT와 무선인터넷의 발달에 따라 디지털 컨텐츠를 담는 뉴미디어로서의 휴대폰의 가능성은 점차 확대되고 있으며, 모바일 컨텐츠 시장도 급속도로 성장하고 있다. 무선인터넷의 발달은 유선 인터넷 컨텐츠를 무선으로 확장하게 하였으며, 장소기반 관광 정보 (Location Based Information) 서비스가 우선적으로 구축되고 있다. 그러나, 현재 모바일 기기로 서비스되고 있는 대부분의 관광정보는 관광지에 대한 간단한 설명, 교통편, 숙박, 음식점 등 매우 실용적이고 일반적이어서 편리하긴 하지만, 그다지 사용하고 싶은 매력은 없는 정보에 그치고 있다. 본 연구는 기술적으로 진화하고 있는 유비쿼터스 도시 환경에서 모바일을 활용하여 어떠한 새로운 형태의 관광 컨텐츠가 가능해질 수 있을까 하는 질문에서 출발하였다. 본 논문은 정보통신연구 진흥원의 지원을 받아 진행했던 지역의 역사, 문화 정보 전달을 위한 모바일 투어 게임 "타임트렉" 프로토타입 개발에 관한 리서치, 컨셉, 프로세스를 정리한 것이다. "타임트렉" 프로젝트에서 추구했던 방향은 문화적, 역사적으로 중요한 장소를 투어하면서 모바일 미디어를 활용하여 보다 깊은 역사, 문화 정보를 새롭고 재미있는 방법으로 전달하고자 하는 것이었다. 특히, 사용자의 보다 적극적인 참여와 흥미유발을 위해 시간여행 능력을 가진 탐정이 과거로 시간여행을 통해 사건을 해결하는 롤플레잉 스토리 기반 게임과 물리적 장소에서 답을 찾아야 하는 오프라인 퀘스트 게임의 형식을 포함하는 모바일 투어 게임형태로 구축하였다. 이렇게 함으로써 관광객들에게 보다 그 장소에 대해 알고 싶어 하는 흥미를 유도하고 투어를 완료하게 유도함으로써 만족스럽고 새로운 관광 경험을 제공하는 것을 목적으로 하였다. 새로운 타입의 모바일 관광서비스의 프로토타입 개발에 있어 중점을 두었던 부분은 역사적으로 중요한 장소를 워킹 트레일로 구성하고 그 장소가 가지는 기본적인 문화, 역사적 정보에 오락적 요소(스토리와 게임 요소)를 자연스럽게 혼합하여 흥미로운 컨텐츠를 만들는 것이었으며, 또한 모바일이 가진 위치기반 서비스 기능을 활용하여 효과적으로 컨텐츠를 적재적소에 제시하는 인터페이스 구현에 중점을 두었다. 논문에서는 먼저, 기존의 국내외 모바일 관광정보서비스의 사례 및 연구 동향을 분석하고, 이에 따라 설정한 "타임트렉" 프로젝트의 방향성과, "타임트렉" 프로젝트에서 개발했던 프로토타입에 대하여 요약, 설명하였으며, 사용자 테스트 과정을 기술하였다. 그리고 마지막으로, 시장 세분화에 따른 관광 정보 서비스의 엔터테인먼트화 전략에 대해 논의하였다. 본 연구에서 시도했던 지역의 역사, 문화 관광을 위한 LBS 모바일 기술과 스토리, 게임 등 엔터테인먼트 요소의 결합은 관광객들에게 새로운 형태의 즐거운 관광 경험을 창출할 수 있으며, 관광 산업과 모바일 컨텐츠 산업의 결합이라는 새로운 접근의 장을 개척할 수 있을 것이다.

• Korean Journal of Cognitive Science
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• v.21 no.4
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• pp.447-458
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• 2010

Time expressions are a very important form of information in different types of data. Thus, the recognition of a time expression is an important factor in the field of information extraction. However, most previously designed systems consider only a specific domain, because time expressions do not have a regular form and frequently include different ellipsis phenomena. We present a two-level recognition method consisting of extraction and transformation phases to achieve generality and portability. In the extraction phase, time expressions are extracted by atomic time units for extensibility. Then, in the transformation phase, omitted information is restored using basis time and prior knowledge. Finally, every complete atomic time unit is transformed into a normalized form. The proposed system can be used as a general-purpose system, because it has a language- and domain-independent architecture. In addition, this system performs robustly in noisy data like SMS data, which include various errors. For SMS data, the accuracies of time-expression extraction and time-expression normalization by using the proposed system are 93.8% and 93.2%, respectively. On the basis of these experimental results, we conclude that the proposed system shows high performance in noisy data.

• Journal of KIISE:Computing Practices and Letters
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• v.12 no.2
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• pp.91-101
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• 2006

Researches on services of vehicles have been mainly focused on how to provide useful information and entertainment for an in-vehicle driver. However, the needs are appreciably increased for more advanced services that help drivers to check and manage their vehicles conveniently, without requiring drivers to attach to their vehicles. It is a sort of ubiquitous computing, providing an intelligent interactive services for human at any time and any where. In this paper, we present an intelligent vehicle information system to enable a driver to remotely diagnose and control a vehicle via CDMA communication network connected to the Internet. The system improves mobility for diagnosis and control of vehicle by implementing a cut and call back mechanism, which allows the vehicle terminal to have access to the information server on the Internet via CDMA call. No matter where the driver is, he can obtain the remote diagnosis and control services on the web browser without any additional application installation. Design methodology is introduced and evaluation results are analyzed for the CDMA-based intelligent vehicle information system. The experimental results show that the response time of the vehicle terminal to a web client request is 10.302 seconds at the beginning and 646.44ms thereafter. The average response time of CAN sensor node to a vehicle terminal request is 6.669ms.