• The Journal of Korean Institute of Communications and Information Sciences
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• v.37C no.9
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• pp.811-820
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• 2012

GNSS signal is vulnerable to jamming signal because of well-known signal structure and weak signal power. For these reasons, the need for analysis of jamming effects and anti-jamming techniques of is increasing. In this paper, a GNSS signal generator is designed which includes a radio wave propagation model for six kind of tactical environments and a body masking model for the reception environment of a vehicle. The radio wave propagation model for downtown, rural, forest, coastline, waste land and snow or ice area is designed using two-ray model. The body masking model is designed the effect which the antenna is affected by the reception environment of a vehicle and radiation pattern from a user configuration. The performance of generated signals from the GNSS signal generator considering reception environment of a vehicle is evaluated by a commercial GPS L1 receiver(NordNav) in normal and jamming environment. Also, the generated GNSS signal is compared to a commercial GPS L1 H/W based RF signal generator(STR4500). The results show that the designed GNSS signal generator in a normal environment compared to the same navigation performance. In jamming environment, it is shown that the body masking effect and GNSS signal acquisition and tracking loss in compliance with the jamming signal are precisely working in the reception environment of a vehicle.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.6
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• pp.813-826
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• 2022

AI-based image processing technologies in various fields have been widely studied. However, the lighter the board, the more difficult it is to reduce the weight of image processing algorithm due to a lot of computation. In this paper, we propose a method using deep learning for object recognition algorithm in lightweight embedded boards. We can determine the area using a deep neural network architecture algorithm that processes semantic segmentation with a relatively small amount of computation. After masking the area, by using more accurate deep learning algorithm we could operate object detection with improved accuracy for efficient neural network (ENet) and You Only Look Once (YOLO) toward executing object recognition in real time for lightweighted embedded boards. This research is expected to be used for autonomous driving applications, which have to be much lighter and cheaper than the existing approaches used for object recognition.

• Proceedings of the IEEK Conference
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• 2002.06e
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• pp.235-238
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• 2002

This paper proposes a novel scheme of designating non-cacheable addresses of memories in embedded systems of multi-master architectures without a Memory Management Unit (MMU). As a solution for data coherency problem between external memories and a cache memory, we proposes a cache masking scheme by allocating the most significant bit of address not used in 32-bit address system as indicator bit to designate non-cacheable address. As this scheme enables non-cacheable area designation every address, the simpler in the aspect of hardware and more flexible size of non-cacheable area can be obtained.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.3
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• pp.349-356
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• 2004

The automatic recognition of transport containers using image processing is very hard because of the irregular size and position of identifiers, diverse colors of background and identifiers, and the impaired shapes of identifiers caused by container damages and the bent surface of container, etc. In this paper we propose and evaluate a novel recognition algorithm for container identifiers that effectively overcomes these difficulties and recognizes identifiers from container images captured in various environments. The proposed algorithm, first, extracts the area containing only the identifiers from container images by using CANNY masking and bi-directional histogram method. The extracted identifier area is binarized by the fuzzy binarization method newly proposed in this paper. Then a contour tracking method is applied to the binarized area in order to extract the container identifiers which are the target for recognition. In this paper we also propose and apply a novel ART2-based hybrid network for recognition of container identifiers. The results of experiment for performance evaluation on the real container images showed that the proposed algorithm performs better for extraction and recognition of container identifiers compared to conventional algorithms.

• Proceedings of the KAIS Fall Conference
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• 2003.11a
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• pp.88-95
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• 2003

The automatic recognition of transport containers using image processing is very hard because of the irregular size and position of identifiers, diverse colors of background and identifiers, and the impaired shapes of identifiers caused by container damages and the bent surface of container, etc. We proposed and evaluated the novel recognition algorithm of container identifiers that overcomes effectively the hardness and recognizes identifiers from container images captured in the various environments. The proposed algorithm, first, extracts the area including only all identifiers from container images by using CANNY masking and bi-directional histogram method. The extracted identifier area is binarized by the fuzzy binarization method newly proposed in this paper and by applying contour tracking method to the binarized area, container identifiers which are targets of recognition are extracted. We proposed and applied the ART2-based RBF network for recognition of container identifiers. The results of experiment for performance evaluation on the real container images showed that the proposed algorithm has more improved performance in the extraction and recognition of container identifiers than the previous algorithms.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.1
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• pp.80-87
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• 2004

In this paper we proposed the novel feature extraction method that is able to extract the individual characters from the license plate area of the car image more precisely by using the RGB color information and the fuzzy binarization newly proposed. The proposed method, first, extracts from the original image the areas that the pixels with the colors around the green are concentrated on as the candidate areas of the license plate, and selects the area with the most intensive distribution of pixels with the white color among the candidate areas as the license plate area. Second the noises of the license plate area should be removed by using 34{\times}$3 Sobel masking, and the fuzzy binarization method are proposed and applied to the license plate area to generate the binarized image of the license plate area. Lastly, the application of the contour tracking algorithm to the binarized area extracts the individual characters from the license plate area. The experiment on a variety of the real car images showed that the proposed method generates the higher rate of success for character extraction than the previous methods.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.3
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• pp.815-820
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• 2010

Fuel spray characteristics of the gasoline engine injector has been studied experimentally. Wall wetting fuel stream of the 4-hole and 12-hole injectors has been tested and measured with various installation angle and port masking shapes. Spray visualization has been performed to analyze spray formation, spray angle, and penetration length. Test result shows that wall wetting is greatly influenced by the induction air flow and injector installation angle. Wall wetting amount decreased as injector installation angle decreased. Masking decreased wall wetting amount by increasing local intake-air flow velocity due to the decreased section area. Spray visualization showed that the 12-hole injector has robust performance characteristics compared with the 4-hole injector.

• Journal of Preventive Medicine and Public Health
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• v.6 no.1
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• pp.43-49
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• 1973

In this study noise source in a ward at four general hospitals in Seoul area has been investigated and analysed. The degree of reaction against noise by 171 randomly has also been examined. The results of the study have shown that the source of noise is the speakers of wired broadcasting or from visiting guests in two hospitals located in residential area. The patients at the two other hospitals located at commercial site have been suffered more from traffic noise. However, because of their separated living at hospital from their ordinary houselife, sixty one percent of the inpatients have wished a music sound of around 60 dB (A). After having considered the results of the investigation and wishes of the inpatients, following suggestions have been made: 1. Reduce the number of guests or their length of stay. 2. Wired broadcasting system should be substitued by wireless one, or if it's unavoidable, it should be used in office rooms only. 3. Since the stops and starts of vehicles induce much noise, Seoul City Government be requested to prepare an appropriate administrative measure for the vehicles around hospital area and it should prevent the establishment of new hospitals along high way site. 4. By using earphone, inpatients can choose a wireless channel according to each individual's taste. This through the masking effect, would cover up the noise source. 5. Rooms along the streets should be utilized as offices, otherwise double windows should be set up for inpatient's wards.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.2
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• pp.173-180
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• 2000

During the last decade many researches have been working on multiple target tracking problem in the area of radar application, Various approaches have been proposed to solve the tracking problem and the concept of sensor fusion was established as an effort. In this paper utilization of geographic information for ground target tracking is investigated and performance comparison with the results of applying sensor fusion is described. Geographic information is used in three aspects: association masking target measurement and re-striction of removing true target. Simulation results indicate that using two sensors shows better performance with respect to tracking but a single with geographic information is a winner in reducing the number of false tracks.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.05
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• pp.241-244
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• 1997

23 hallux valgus patients were evaluated with clinical examinations and plantar pressure distribution measurements. A masking method for detailed plantar pressure distribution analyses was suggested. With higher grade of hallux valgus, pressure, contact length & area, and impulse on metartasus were significantly increased. Localized pressure concentration is very important in foot diseases and appropriate plantar pressure distributions should be considered on any shoe design.