• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.7
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• pp.1624-1637
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• 2013

In RFID systems, one important issue is how to effectively address tag collision, which occurs when multiple tags reply simultaneously to a reader, so that all the tags are correctly identified. However, most existing anti-collision protocols assume isotropic collisions where a reader cannot detect any of the tags from the collided signals. In practice, this assumption turns out to be too pessimistic since the capture effect may take place, in which the reader considers the strongest signal as a successful transmission and the others as interference. In this case, the reader disregards the other collided tags, and in turn, fails to read the tag(s) with weaker signal(s). In this paper, we propose a capture effect-aware anti-collision protocol, called Multi-Round Collision Tree (MRCT) protocol, which efficiently identifies the tags in real RFID environments. MRCT deals with the capture effect as well as channel error by employing a multi-round based identification algorithm. We also analyze the performance of MRCT in terms of the number of slots required for identifying all tags. The simulation results show that MRCT significantly outperforms the existing protocol especially in a practical environment where the capture effect occurs.

• The Journal of Korea Robotics Society
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• v.11 no.3
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• pp.127-132
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• 2016

For a practical mobile robot team such as carrying out a search and rescue mission in a disaster area, the localization have to be guaranteed even in an environment where the network infrastructure is destroyed or a global positioning system (GPS) is unavailable. The proposed architecture supports localizing robots seamlessly by finding their relative locations while moving from a global outdoor environment to a local indoor position. The proposed schemes use a cooperative positioning system (CPS) based on the two-way ranging (TWR) technique. In the proposed TWR-based CPS, each non-localized mobile robot act as tag, and finds its position using bilateral range measurements of all localized mobile robots. The localized mobile robots act as anchors, and support the localization of mobile robots in the GPS-shadow region such as an indoor environment. As a tag localizes its position with anchors, the position error of the anchor propagates to the tag, and the position error of the tag accumulates the position errors of the anchor. To minimize the effect of error propagation, this paper suggests the new scheme of full-mesh based CPS for improving the position accuracy. The proposed schemes assuring localization were validated through experiment results.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.5
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• pp.693-701
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• 2018

Transfer types at the Seoul Metropolitan Urban Railway Stations can be classified into transfer between lines and station transfer. Station transfer is defined as occurring when either 1) the operating line that operates the tag-in card-reader and that operating the first train boarded by the passenger are different; or 2) the line operating the final alighted train and that operating the tag-out card-reader are different. In existing research, transportation card data is used to estimate transfer volume between lines, but excludes station transfer volume which leads to underestimation of volume through transfer passages. This research applies transportation card data to a method for station transfer volume estimation. To achieve this, the passenger path choice model is made appropriate for station transfer estimation using a modified big-node based network construction and data structure method. Case study analysis is performed using about 8 million daily data inputs from the metropolitan urban railway.

• Korean Journal of Agricultural Science
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• v.39 no.3
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• pp.377-386
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• 2012

To reduce the saturation level of lard, solvent fractionation with hexane and acetone was carried out. The fatty acid compositions of lard were 1.5% myristic acid, 26.0% palmitic acid, 2.2%, palmitoleic acid, 12.1% stearic acid, 44.7% oleic acid, and 12.7% linoleic acid. Lard was fractionated by various conditions such as different fractionation temperatures (-15, 5, 10, $15^{\circ}C$), solvent ratios (1:1, 1:3, 1:5, 1:10, lard : solvent, w/v), and fractionation time (3, 6, 24 hr). At $-15^{\circ}C$, acetone was better for reducing the content (11.2%) of saturated fatty acids (SFA) than hexane (10.8%) when the 1:5 solvent ratio was used at 24 hr. Triacylglycerol (TAG) profiles were analyzed by reversed-phase high performance liquid chromatography based on the partition number (PN) of TAG molecules. The PN of major TAG species in lard were 46 (24.4%), 48 (55.7%), and 50 (19.9%). However, after fractionation (1:5, $5^{\circ}C$ and 24 hr), TAG species with a PN of 46 (34.2%), 48 (54.4%), and 50 (6.9%) were major components in acetone-fractionated lard (liquid part), while TAG species with a PN of 46 (26.0%), 48 (50.3%), and 50 (19.0%) were in hexane-fractionated lard, suggesting that fractionation with acetone resulted in maximal reduction of saturation level in lard.

• Fashion & Textile Research Journal
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• v.16 no.5
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• pp.800-810
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• 2014

In this study, the current status of product information of functional outdoor jackets in the hang-tags was investigated in perspective of consumer protection. Effectiveness and preferred alternatives to hang-tag information were also investigated. For the market survey, 1560 hang-tags from 676 functional outdoor jackets were investigated. For the effectiveness and preferred alternatives, 472 adults in their 20-60's were surveyed. The average number of hang-tags was 2.3 but 5.9% did not provide any product information. The contents included functional property of fabric; quality guarantee; brand introduction; product characteristics; instructions for care/usage; subsidiary material information, and they were different depending on end-use of jackets. Consumers strongly wanted explanations of the terms used in the hang-tag and could not accurately figure out the functions of the products from hang-tag information regardless of expression methods. The percentage of incorrect answer of 'figure/foreign language' method was extremely high. It is a noticeable feature of graph method that customers perceived that the graph was difficult to understand, but the percentage of correct answers was much higher than other methods, implying that graph method was possibly more useful at delivering accurate information to the customers who pursuit information. Customers strongly agreed to need of alternative methods and preferred an unified performance grade from selected functions based on the end-use of products. Customers also wanted to include the information of performance change after laundering. The results could provide practical insights to the consumers, companies, and the government to prepare proper guideline/policies for consumer protection.

• Journal of KIISE
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• v.42 no.5
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• pp.637-641
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• 2015

Due to the recent increasement of user created contents like SNS, blog posts, and so on, broadcast contents are actively re-construction by its users. Especially, on some genres like drama, movie, various information from cars and film sites to clothes and watches in a content is spreaded out to other users through blog postings. Since such information can be an additional information for the content, they can be used for providing high-quality broadcast services. For this purpose, in this paper, we propose timeline tag cloud generation method for broadcasting contents. In the proposed method, blog postings on the target contents are first gathered and then, images and words around images are extracted from a blog post as a tag set. An extracted tag set is tagged on a specific timeline of the target content. In experiments, to prove the efficiency of the proposed method, we evaluated the performances of the proposed image matching and tag cloud generation methods.

• Journal of the Institute of Convergence Signal Processing
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• v.9 no.1
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• pp.46-53
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• 2008

This paper presents a 13.56 MHz RFID reader that can be used as a door-lock system for smart home security. The RFID reader consists of a transmitter, a receiver, and a data processing block. To verify the operation of the developed RFID reader, we present both a PSPICE simulation for transmitter/receiver and a digital simulation for data processing block. In particular, a CRC block for error detection of received data and a Manchester decoding block for position detection of collided data are designed using VHDL. In addition, we applied a binary search algorithm for multi-tag anti-collision. The anti-collision procedure is carried out by PIC microcontroller on software. The experimental results show that the developed reader can provide the right multi-tag recognition.

• Journal of Ship and Ocean Technology
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• v.12 no.3
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• pp.26-35
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• 2008

Recognition of real time locations of crews for a naval ship is important, not only for the operation efficiency but also for the safety of onboard crews in the ship. More than 100 crews are dwelling in a modem naval ship and they are involved in various duties. Moreover many visitors come in and out frequently while the ship is moored in a harbor. It sometimes requires considerable time and efforts to find a person for urgent mission. It would enhance the operational efficiency if locations of onboard crews are recognized and monitored in real time. An active type RFID tag, which has a specific ID number, is distributed to each crew member, which should be carried during his stay in the ship. A number of fixed type RFID readers are to be located at the major passages of the ship, which are connected to the main computer via Local Area Network. The location of a crew would be identified by the ID number of his RFID tag and the location of the RFID reader which detected the RFID tag. A middleware is needed to process the collected data in the main computer. The data is fed to application softwares, which actually display locations of the concerned crews. The software is coded using GUI (Graphic User Interface) for better user friendliness, which has the function of storing the location history of a crew, and sending warning messages to appropriate persons, if unallowable behavior is detected. An auxiliary naval ship is selected for an experimental application study of the proposed system. It turns out that the required budget and time for the realization of the system is within the allowable limits. But complementary measures to protect the privacy of onboard crews should be considered and adopted, before the application of the system is realized.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.2
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• pp.302-312
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• 2012

In this paper, small-area and high-reliability design techniques of a 512-bit EEPROM are designed for UHF RFID tag chips. For a small-area technique, there are a WL driver circuit simplifying its decoding logic and a VREF generator using a resistor divider instead of a BGR. The layout size of the designed 512-bit EEPROM IP with MagnaChip's $0.18{\mu}m$ EEPROM is $59.465{\mu}m{\times}366.76{\mu}m$ which is 16.7% smaller than the conventional counterpart. Also, we solve a problem of breaking 5V devices by keeping VDDP voltage constant since a boosted output from a DC-DC converter is made discharge to the common ground VSS instead of VDDP (=3.15V) in getting out of the write mode.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.51 no.2
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• pp.227-234
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• 2015

To obtain geographical range and growth-kinetics parameters of mottled sake (Beringraja pulchra) populations in the Yellow Sea, three mark-recapture experiments were carried out. Overall, 991 tagged individuals were released, and 4.1% of them were recaptured with the mean release period of 339 d (range, 8-1,420 d) and the mean growth rate of $1.4cm\;mon^{-1}$ (female, $1.5cm\;mon^{-1}$; male $1.3cm\;mon^{-1}$). In the first experiment, 667 individuals were released at Heuksan Island from April to June, 2007-2009, and 30 individuals were recaptured mainly at the north and the north-east coasts of the island, indicating absence of migration to the south of the island. In the second experiment, 323 individuals were released at several fishing grounds scattered in the Yellow Sea in 2010-2013, and 11 individuals were recaptured at points deviated to all directions from the releasing points. As the last, one individual was released with pop-up satellite archival tag at a costal point ($34^{\circ}37.2$'N, $124^{\circ}59.3$'E) off Hong Island on May 21, 2010. The tagged individual migrated to a north-east location ($35^{\circ}50.4$'N, $126^{\circ}03.6$'E) of Eocheong Island by Aug. 25, 2010. The data archived for the three months in the tag indicated that the migration path had depths of 48-80 m and temperature of $12.6-14.4^{\circ}C$. The results indicated that mottled sake populations had a localized habitat ranges at the north of Heuksan Island and the west of Hong Island while growing at the rate of $1.4cm\;mon^{-1}$.