• Journal of the Institute of Electronics Engineers of Korea CI
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• v.44 no.2 s.314
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• pp.47-59
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• 2007

Recently, Healthcare system has not been standardized and has been developed as an embedded system lacking interoperability. We are finally going to face such problems as having excessive load in using network caused by the uncontrolled spread of system and un-guaranteed interoperability among the heterogeneous systems. We suggest the possibility that OSGi and JADE can be accepted as a solution for the above problems.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.10
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• pp.1-6
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• 2007

Wireless Self-Powered Temperature Sensor for UHF Sensor Tags which are basic device for construction of ubiquitous sensor network is proposed. The key parameters of the target specification are resolution of $0.1\;^{\circ}C$ per output bit, below 1.5 V of operating voltage and below 5 uW of power consumption during sensing operation. Temperature sensor circuit consists of PTAT current generator, band gap reference circuit generating both reference voltage and current, Sigma-Delta Converter, and Digital Counter. Simulated maximum resolution was $0.23\;^{\circ}C/bit$ in 11-bit output. The proposed temperature sensor was fabricated by using a 0.25 m CMOS process. The chip area is $0.32\;{\times}\;0.22\;mm$ and the operating frequency is 2 MHz. Measured resolution from fabricated temperature sensor was $4\;^{\circ}C/bit$ in 8-bit output for the temperature range from $10^{\circ}C$ to $80^{\circ}C$.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.5
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• pp.26-37
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• 2009

This paper suggests a sensor's placement method for detecting the dilemma zone problem when real-time driver's safety service is provided at signalized intersections by multiple pointed traffic sensors using USN environments. For detecting the dangerous situations from vehicles accelerating through yellow intervals, red-light running and stopping abruptly like as dilemma zone problem, VISSIM(microscopic, behavior-based multi-purpose traffic simulation program) is used to perform a real-time multiple detection situation by changing the input data like as various inflow-volume, design speed change, driver perception and response time. As a result, the optimal interval of traffic sensors is 20~27m, and the initialized sensor location from stop-line is different according to road design speed. Moreover, the pattern of detection about dilemma zone is also different according to inflow-volumes. This paper shows that the method is useful to evaluate the sensor's placement problem based on micro-simulation and the results can be used as the basic research for USN services.

• The Journal of Society for e-Business Studies
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• v.19 no.1
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• pp.145-157
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• 2014

The advent of ubiquitous connectivity from smart devices and network is changing the lifestyles of workers and work patterns. However, the smart work for the knowledge workers and mobile workers is not yet popular due to not enough services in supporting smart work and difficulties in employing smart work. For these reasons, it is necessary to study the current smart work industry to provide the bases for incubating smart work industry and increasing the smart work adoption. In this study, first, we reviewed and analyzed the smart work services. And then, we classified the smart work industry based on their services. Second, we conducted a survey study to identify the factors that affect on the adoption of smart work. Finally, we provided the current adoption rate of smart work services and discussed the Willing-To-Use, cost, and barriers from the smart work adoption.

• Journal of the Korea Society of Computer and Information
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• v.15 no.12
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• pp.237-245
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• 2010

Korea Communications Commission (KCC) has been providing the pilot service of URC(Ubiquitous Robot Companion), which is a network-based personal robot, to 1000 Korean households since 2006 to define potential users' needs and adoption behaviors. Personal innovativeness might play a critical role in adoption of URC services by users because much sophisticated and convergence technologies are incorporated into URC services. Also, defining not only perceived beliefs about URC services but also expected beliefs about them are very crucial to reduce disconfirmation between users' perception and expectation of URC services. From this point of view, this paper aimed to examine robot users' adoption behavior by considering constructs such as personal innovativeness, usefulness (perceived usefulness - expected usefulness, P-E), user attitude, and intention to use. The findings reveal that personal innovativeness is negatively related to usefulness (P-E) whereas usefulness (P-E) influences significantly and positively on user attitude. It is also shown that usefulness (P-E) and user attitude have strong positive effects on intention to use.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.5
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• pp.1011-1016
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• 2018

Ubiquitous services for the convenience and safety of human beings along with the development of society are being realized through RFID technology and sensor network, and its application range of fields is also broaden. However, since the USN contains all the information of individuals and things, all of its private spaces can be attacked by external attacks; so, that the problem of security continues to arise. We designed a one-way chaotic feedback synchronization method as a secure communication method to fit the USN composed of one sync node and n number of sensor nodes. We designed the method by which the sensor node is synchronized in one direction of the sync node. This method solves the problem that all sensor nodes need to be resynchronized when the sync node is changed, which is shown in bidirectional synchronization. This is a security method that can be effectively applied to 1:n communication such as USN.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.763-766
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• 2005

Ubiquitous Computing owes Internet and development of computer network and appeared. RFID (Radio frequency Identification) technology is noted by point technology to realize this. However, PML that present in Auto-lD Center is defined point part to describe information of object, and necessary part is to use defining extension separately in actuality application. So that can define object type that can be used for electron tag data processing in RFID application service because do fetters to Auto-lD Center's PML Core in this treatise hereupon and apply in physical distribution circulation service field, designed object information data model.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.11C
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• pp.1498-1509
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• 2004

In this paper, we evaluate the performance of a noncoherent OOK (On-Off Keying) UWB (Ultra Wide Band) system based on power detection with noise power calibration and noise power windowing for ubiquitous sensor network applications in typical indoor wireless channels. Utilizing noise power calibration and noise power windowing, the current noise information can be initially or adaptively provided to determine suitable detection threshold value for signal demodulation. Simulation results show that the noncoherent OOK UWB system using noise power calibration achieves good BER (Bit Error Rate) performance which is favorably comparable to that of the system using the ideal adaptive threshold, while maintaining simple receiver structure. However, despite the serious loss of the data transmission rate, the performance improvement by noise power windowing is not so remarkable. furthermore, these performance results are similarly maintained in BEE 802.15 Task Group 3a UWB indoor channel model, and it is also revealed that the BER performance can be significantly improved by increasing the pulse repetition rate.

• Journal of Sensor Science and Technology
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• v.19 no.3
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• pp.169-175
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• 2010

Urinalysis is an important clinical test to diagnose urinary diseases, and dipstick method with visual inspection is widely applied in practice. Automated optical devices recently developed have disadvantages of long measurement time, big size and heavy weight, accuracy degradation with time, etc. The present study proposed a new computer scanning technique, in which the test strip and the standard chart were simultaneously scanned to remove any environmental artifacts, followed by automated differentiation with the minimum distance algorithm, leading to significant enhancement of accuracy. Experiments demonstrated an accuracy of 100 % in that all test results were identical with the human visual inspection. The present technique only uses a personal computer with scanner and shortens the test time to a great degree. The results are also stored and accumulated for later use which can be transmitted to remote locations through a network, thus could be easily integrated to any ubiquitous health care systems.

• Journal of Satellite, Information and Communications
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• v.9 no.2
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• pp.85-90
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• 2014

In this paper, we propose a novel UE(User Equipment) position tracking algorithm of visible light signals, and analyze BER performance when optical beamforming scheme is applied in VLC(Visible Light Communications) system. The optical beamforming scheme as an interference mitigation method provides good optical channel conditions between UE(Rx) and LED light(Tx), and lead to better BER performance because UE is able to get a better RSSI(Received Signal strength indication) value. For the system BER, the proposed UE position tracking method for optical beamforming transmission demonstrates the performance enhancement compared to a system not applied the optical beamforming transmission scheme, and up to about 5~6dB SNR performance gain is achieved. The results of the paper can be applied to design of various VLC and LBS applications for ubiquitous home network systems.