• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.5
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• pp.157-171
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• 2021

As smartphones spread and ICT technologies develop, taxi services have changed from hovering to platform-based calls and reservations. This has improved the mobility and accessibility of taxi users but caused problems, such as digital observing (no-responses to calls) for either short-distance services or services during the peak-demand periods. Digital Observing means ignoring and not accepting calls when they occur, which require improvement. Therefore, this study aims to derive measures to mitigate discrepancies in taxi supply and demand by adjusting the expected revenue of each taxi service using reinforcement learning based on the Taxi operation data. The results confirmed that the average complete response rate to calls would increase from 50.29% to 54.24% when incentives are applied, and an improvement of 5.86% can be achieved in short-distance sections of less than 5,000 won incentives. It is expected that the improvement will increase profitability for drivers, reduce the waiting time for passengers, and improve satisfaction with taxi services overall.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.2
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• pp.301-306
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• 2021

In the field of year-based interpretation of important data, memory laws can be used as a way to enhance educational effectiveness. Studies related to how to remember numbers are conducted in the form of increasing memory rates by presenting information in the form of conventional simple images. We attempt to supplement the method proposed in the paper of numerical algorithm for modifying errors based on mnemonic system in mobile environments. We want to complement the error correction numerical algorithm proposed in previous work. The study was a way to compensate the errors that occur when users enter numerical information in the apps they use. In this work, we want to increase the memory rate based on two-dimensional information by imposing the concept of angles, rather than simply showing data to help recall memories from mistakes. To this end, we propose a problem-solving process using developed app, and implement and evaluate the short distance valid algorithms.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.4 no.4
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• pp.159-176
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• 2023

The conservation of the raccoon dog (Nyctereutes procyonoides) in South Korea requires the protection and preservation of natural habitats while additionally ensuring coexistence with human activities. Applying habitat map modeling techniques provides information regarding the distributional patterns of raccoon dogs and assists in the development of future conservation strategies. The purpose of this study is to generate potential habitat distribution maps for the raccoon dog in South Korea using geospatial technology-based models. These models include the frequency ratio (FR) as a bivariate statistical approach, the group method of data handling (GMDH) as a machine learning algorithm, and convolutional neural network (CNN) and long short-term memory (LSTM) as deep learning algorithms. Moreover, the imperialist competitive algorithm (ICA) is used to fine-tune the hyperparameters of the machine learning and deep learning models. Moreover, there are 14 habitat characteristics used for developing the models: elevation, slope, valley depth, topographic wetness index, terrain roughness index, slope height, surface area, slope length and steepness factor (LS factor), normalized difference vegetation index, normalized difference water index, distance to drainage, distance to roads, drainage density, and morphometric features. The accuracy of prediction is evaluated using the area under the receiver operating characteristic curve. The results indicate comparable performances of all models. However, the CNN demonstrates superior capacity for prediction, achieving accuracies of 76.3% and 75.7% for the training and validation processes, respectively. The maps of potential habitat distribution are generated for five different levels of potentiality: very low, low, moderate, high, and very high.

• Journal of Advanced Navigation Technology
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• v.26 no.3
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• pp.160-165
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• 2022

In this paper, we have proposed a magnetic resonant 6.78MHz WPT(wireless power transfer) technique which can be applied to a fixed transmitter and a receiver of varying relative distance and coil alignment, Power transmission characteristics are studied with the relative distance and misalignment ration of coil area between the transmitting and receiving coils. The coils are designed with the size of 60×80mm² by direct feeding method, and the characteristics are derived with the maximum relative distance of 50mm and horizontal area misalignment state of 0-40mm misalignment of coil center axis in the XY plane. The power transmission characteristics are compared between the 3D EM simulation and the measured data, and the power transmission shows larger than -3dB performance with the vertical distance of up to 30mm and 50% area misalignmment ratio. This work showsthe transmission characteristics according to relative distance and misalignment state between the cols and that direct feeding has advantage for the short relative distance and small misalignment ratio.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.12
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• pp.1609-1613
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• 2009

The objective of this study was to estimate genetic parameters for racing performance traits of thoroughbredracehorses, using a total of 58,124 racing records of 4,200 horses at Gwacheon Racing Park collected from January 2002 to December 2006. This study measured start one furlong time, last three and last one furlong times, and the resulting furlong time averages were 14.2 seconds, 39.9 seconds and 13.9 seconds, respectively. Furlong time means a split time measured based on a 1/8-mile (or approximately 201 m) distance and finished time means total racing time measured from start position to finish line. In the shortest distance races of 1,000 m, the average last three and last one furlong time was fastest at 38.7 seconds and 13.6 seconds, respectively. The correlation between finished time and start one furlong time decreased as the race distance increased, and the same trend was recognized from the correlation between finished time and last three furlong time. In short distance races of 1,400 m or less, the starting ability was found to be an important trait. The average speed was highest at 56 km/h for a 1,000 m race and lowest at 53.2 km/h for a 1,700 m race. Heritabilities of the start one furlong time, the last three and last one furlong time were estimated to be 0.337, 0.245 and 0.210, respectively; and repeatabilities for them were 0.452, 0.353 and 0.309, respectively. Phenotypic and genetic correlations between the start and the last one furlong time were negative at -0.141 and -0.155, respectively.

• The Journal of Korean Association of Computer Education
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• v.18 no.6
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• pp.33-42
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• 2015

Based on the Construal Level Theory, this study aims to investigate how information security vaccine users' selection intentions differ from each other according to the selection time of information security vaccine, advertisement message types, and information security knowledge levels. For the foregoing, this study conducted an experiment by applying an experimental design of 2(knowledge level: high/low) ${\times}2$(temporal distances: short distance/long distance) ${\times}2$(advertisement message types: how(concrete)/why(abstract)) on computer security vaccine softwares. As a result, this study confirmed that the selection intentions about information security vaccines differed from each other according to the temporal distance and advertisement message type, and also varied according to the information security knowledge level. In conclusion, this study provides an implication that the consideration of well-timed persuasive message is especially important for the users at the high level of knowledge. Also, this research implies the necessity of development of abstract thinking ability based on temporal distance for the users at the low level of knowledge.

• International Journal of Internet, Broadcasting and Communication
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• v.9 no.2
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• pp.64-69
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• 2017

The abstract should summarize the contents of the paper and written below the author information. Use th In Wide-area Wireless Sensor Networks, network lifetime is short due to energy consumption due to transmission distance. To improve this, we divide the sensor field into layers and reduce transmission distance through multi-hop transmission. However, there is a problem in that the transmission rate drops because there is no Cluster Head in the layer, or the transmission distance increases due to the layer, and energy is wasted. There are DL-LEACH and EDL-LEACH as Protocols to improve this. DL-LEACH uses either single-hop transmission or multi-hop transmission depending on the situation. As a result, the transmission distance is optimized, thereby reducing energy consumption. In case of EDL-LEACH, it is proposed to improve the data rate in DL-LEACH. It is the same as DL-LEACH, but the Cluster Head is mandatory for all layers to improve the transmission rate. Although there is no Cluster Head for each layer, the transmission rate is improved, but the network life is shortened. In this paper, we try to improve the network lifetime while maintaining the EDL-LEACH transmission rate. The shortened network lifetime is due to Cluster Head overload near the base station. To improve this, the Cluster Head distribution method is improved and the network lifetime is improved.

• Journal of Aquaculture
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• v.17 no.1
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• pp.12-23
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• 2004

Genomic DNAs were extracted from the muscle of twenty-two specimens of two shortnecked clam, Ruditapes phifippinarum populations collected in Anmyeondo and Seocheon. Genetic differences within and between populations were analysed by random amplified polymorphic DNAs-polymerase chain reaction (RAPD-PCR) using twenty arbitrary decamer primers. Out of 20 primers, 6 generated a total of 1,111 major and minor RAPD bands from individuals of two sites, producing approximately 4.2 average polymorphic bands per primer in individuals from Anmyeondo and ranging in size from less than 50 to larger than 1,500 base pairs (bp). The electrophoretic analysis of RAPD products amplified showed moderate levels of similarity among the different individuals in Seo-cheon population. The average bandsharing values (BS value) of the samples within population from Anmyeondo ranged from 0.155 to 0.684, whereas it was 0.143∼0.782 within population from Seocheon. The average BS value between individuals No. 13 and No. 14 from Seocheon was 0.782 which was higher than that of those from Anmyeondo. The single linkage dendrogram resulted from three primers (OPA-08, -09 and -20), indicating six genetic groupings composed of group 1 (No.4, 8 and 10), group 2 (No. 18), group 3 (No.2, 5 and 7), group 4 (No. 1, 3, 6, 9, 11, 12, 13, 14, 15 and 17), group 5 (16, 19 and 20) and group 6 (No. 21 and 22). In the Seocheon population, the individual No. 18 clustered distinctly from the others of this population. The observed genetic distance between the two populations from Anmyeondo and Seocheon was more than 0.209 (0.247 and 0.275). The shortest genetic distance (0.094) displaying significant molecular differences was between individuals No. 13 and No. 14. Especially, the genetic distance between individuals No. 22 and the remnants among individuals in two geographical populations was highest (0.275). This result illustrated that individual No.22 is distinct from other individuals within two shortnecked populations. The different geographical features of two sites may have caused the genetic diversity in two shortnecked clam populations.

• The Journal of the Acoustical Society of Korea
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• v.19 no.8
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• pp.68-77
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• 2000

Line special frequency (LSF) parameters have been widely used in low bit-rate speech coding due to their efficiency for representing the short-time speech spectrum. In this paper, a new distance measure based on the masking properties of human ear is proposed for quantizing LSF parameters whereas most conventional quantization methods are based on the weighted Euclidean distance measure. The proposed method derives the perceptual distance measure from the definition of noise-to-mask ratio (NMR) which has high correspondence with the actual distortion received in the human ear and uses it for quantizing LSF parameters. In addition, we propose an adaptive bit allocation scheme, which allocates minimal bits to LSF parameters maintaining the perceptual transparency of given speech frame for reducing the average bit-rates. For the performance evaluation, we has shown the ratio of perceptually transparent frames and the corresponding average bit-rates for the conventional and proposed methods. By jointly combining the proposed distance measure and adaptive bit allocation scheme, the proposed system requires only 770 bps for obtaining 95.5% perceptually transparent frames, while the conventional systems produce 89.9% at even 1800 bps.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.3
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• pp.47-53
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• 2017

There is a difficulty in preventing drunken driving by enforcing alcohol control on the sea due to the environment of Marine transportation rather than roads. In the previous study, we proposed the algorithm, that was developed to identify the voices changed according to be drunk. Using the developed algorithm, it became possible to know the possibility of drinking by long distance ship operators and crew members. In that method drinking can be measured in real time, no matter how far the distance is, if the interception is through a voice that can be transmitted over a distance, rather than a short distance. When communicating voice using the VTS wireless devices, clipping occurs when that environment is uneven, and the rate of judgment of the possibility of drinking may be lowered. Therefore, in this paper, we proposed an enhanced method to compensate the signal in order to reduce the error rate of the possibility of drinking due to distortion of the speech signal.