• The Journal of The Korea Institute of Intelligent Transport Systems
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• 제7권2호
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• pp.43-49
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• 2008

In this paper, new directional couplers for T/R switch of UHF RFID applications are proposed to overcome TX-to-RX leakage problem. The proposed method can remove TX-to-RX leakage caused by both imperfect isolation characteristic of the conventional directional coupler and the mismatch of antenna impedance. Two directional couplers are implemented using distributed elements and lumped elements respectively for the verification. The varactor tuneable circuits for compensation of the antenna mismatch is also proposed. The measurement result shows excellent TX-to-RX leakage suppression, more than 45dB in 910MHz.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• 제11권3호
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• pp.23-30
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• 2012

In this paper, we propose a new near-field reader antenna for 900 MHz RFID. The proposed antenna consists the micro-strip antenna with the periodic structure. The overall dimension of the antenna is $313mm{\times}152mm{\times}14mm$. The antenna has the uniform E-field distribution in near field region and the heart-shaped radiation beam pattern (Peak gain=-2 dBi). The transmitted power range is from 17 dBm to 23 dBm. We focus on minimizing the detected error by suppressing the reflected power from the metal, which is attached to the surface by tag, and by reducing the transmitted power from tag.

• Industrial Engineering and Management Systems
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• 제8권1호
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• pp.37-46
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• 2009

Patient safety has become a growing concern in health care. The U.S. Institute of Medicine (IOM) report "To Err Is Human: Building a Safer Health System" in 1999 included estimations that medical error is the eighth leading cause of death in the United States and results in up to 100,000 deaths annually. However, many adverse events and errors occur in surgical practice. Within all kinds of surgical adverse events, wrong-side/wrong-site, wrong-procedure, and wrong-patient adverse events are the most devastating, unacceptable, and often result in litigation. Much literature claims that systems must be put in place to render it essentially impossible or at least extremely difficult for human error to cause harm to patients. Hence, this research aims to develop a prototype system based on active RFID that detects and prevents errors in the OR. To fully comprehend the operating room (OR) process, multiple rounds of on site discussions were conducted. IDEF0 models were subsequently constructed for identifying the opportunity of improvement and performing before-after analysis. Based on the analysis, the architecture of the proposed RFID-based OR system was developed. An on-site survey conducted subsequently for better understanding the hardware requirement will then be illustrated. Finally, an RFID-enhanced system based on both the proposed architecture and test results was developed for gaining better control and improving the safety level of the surgical operations.

• Journal of Institute of Control, Robotics and Systems
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• 제12궈1호
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• pp.41-46
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• 2006

Ubiquitous location based services, offer helpful services anytime and anywhere by using real-time location information of objects based on ubiquitous network. Particularly, autonomous mobile robots can be a solution for various applications related to ubiquitous location based services, e.g. in hospitals, for cleaning, at airports or railway stations. However, a meaningful and still unsolved problem for most applications is to develop a robust and cheap positioning system. A typical example of position measurements is dead reckoning that is well known for providing a good short-term accuracy, being inexpensive and allowing very high sampling rates. However, the measurement always has some accumulated errors because the fundamental idea of dead reckoning is the integration of incremental motion information over time. The other hand, a localization system using RFID offers absolute position of robots regardless of elapsed time. We construct an absolute positioning system based on RFID and investigate how localization technique can be enhanced by RFID through experiment to measure the location of a mobile robot. Tags are placed on the floor at 5cm intervals in the shape of square in an arbitrary space and the accuracy of position measurement is investigated . To reduce the error and the variation of error, a weighting function based on Gaussian function is used. Different weighting values are applied to position data of tags since weighting values follow Gaussian function.

• Journal of Navigation and Port Research
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• 제29권9호
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• pp.789-793
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• 2005

The container terminals in Korea usually adopts both the bar code and the image recognition systems at the gate complex to capture necessary information on containers passing through the gate. With the rapid advancement of Information Technology(IT) these systems, however, seem to make the user not satisfied due to the inherent limitations such as the long process time taken, low rate of recognition etc., This paper, therefore, examines the adoption of Radio Frequency Identification (RFID) technology to container terminals, and tried to get some implication for the way to improve the productivity of the terminal. The results imply that some improvement in the gate and storage yard operation is feasible by the benefit of using the information of vehicles and containers collected in advance by RFID technology.

• The Journal of the Korea institute of electronic communication sciences
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• 제14권6호
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• pp.1077-1082
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• 2019

The development of computing technology and networking has developed into a fundamental technology of the Fourth Industrial Revolution, which provides a ubiquitous environment. In the ubiquitous environment, the IoT environment has become an issue so that various devices and the things can be actively accessed and connected. Also, the RFID system using the wireless identification code attaches an RFID tag to the object, such as the production and distribution of products. It is applied to the management very efficiently. EPCglobal is conducting a research on RFID system standardization and various security studies. Since RFID systems use wireless environment technology, there are more security threats than wire problems. In particular, failure to provide confidentiality, indistinguishability, and forward safety could expose them to various threats in the Fourth Industrial Revolution. Therefore, this study analyzes the standard method of EPCgolbal and proposes RFID security method using hash code that can consider the amount of computation.

• Tunnel and Underground Space
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• 제26권4호
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• pp.253-265
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• 2016

In this study, travel time data collection of mine equipments was conducted in an underground mine using a reverse Radio Frequency IDentification (RFID) system. In the reverse RFID system, RFID readers and antennas are mounted on mine equipments, and RFID tags are attached to the underground mine gallery. Indoor experiments were performed to analyze how RFID reader transmission power levels affect tag readable area and tag recognition rates. The results showed that travel time measurement become precise when the reader transmission power was reduced, however tag recognition rates were reduced. The field experiments indicated that setting the reader transmission power to 28 dBm maintained the tag recognition rate while minimizing the tracking location error. In addition, the results revealed that the reverse RFID system can be used successfully in an underground mine to collect the travel time data of haulage trucks.

• Journal of Korea Multimedia Society
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• 제14권3호
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• pp.423-432
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• 2011

In a warehouse, because there exist frequent changes of stock status and the quality of some contents are influenced by the environment such as temperature, fast and accurate management of the warehouse's environment is very important for Warehouse Management Systems (WMS). However, due to the absence of a unified standard for the communication protocol between RFID nodes, the connection between RFID nodes can be broken in case of movement of a RFID reader to a region with a different protocol. Moreover, centralized MAC schemes for RFID communications in previous studies have severe problems. For an example, if a cluster header disappears from the cluster due to the cluster header's movement or bad channel conditions, the RFID member nodes of the cluster waste lots of time and energy to re-elect a new cluster header. Therefore, in this paper, we propose a WiMedia Distributed MAC (D-MAC) scheme for RFID communications and its cooperative relay transmission scheme for WMS applications Simulation results show performance improvement at the RFID node by using the proposed cooperative relay transmission scheme.

• Journal of the Korea Institute of Information and Communication Engineering
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• 제14권6호
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• pp.1453-1459
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• 2010

Recently, the aim of cold storage warehouse is not only to provide preservation of the quality of perishable foods but also to use state-of-the-art information systems to rapidly move products across the cold chain. An RFID (Radio Frequency Identification) is an automatic identification method that detects signals from mobile objects, and tracks and traces movement of the objects. RFID can be used to turn a cold storage warehouses into a real-time system. In this paper, we develop an cold storage management system to support the optimized business processes with RFID system. First of all, business processes in the cold storage warehouse are analyzed. Then design factors which should be considered for incorporating RFID are defined. Design values which set to the design factors can be extracted from using RFID deployment simulator. as a result, the design values make RFID to be efficiently integrated to existing business processes.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제9권6호
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• pp.1619-1624
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• 2008

Recently, In order to provide ubiquitous service, we develop each middleware and interface for sensors networks, RFID(Radio Frequency IDentification) and GPS(Global Positioning System). We use GPS for the location-based services, RFID for identifying the distribution logistics services, sensor networks for collecting the context data such as temperature, humidity, barometric pressure. Recently, there is increasing the need of integrated interface for using these sensor elements complexly in agriculture and livestock, construction, medical applications and, etc. This paper developments a integrated common interface for supporting efficiently process of sensing data using RFID, GPS and sensor network. This interface have the filtering function, parsing function, queuing function, interface management function, access function and, etc. We present the integrated frame structure combined with the collected context data in GPS, RFID and sensor networks and, support the open interface for providing complex ubiquitous application systems. Therefore, this interface will be efficiently used the system using RFID, GPS and sensor network, and supported many ubiquitous application services.