• Annual Conference of KIPS
• /
• 2016.10a
• /
• pp.733-734
• /
• 2016

This study proposes a novel approach for ground segmentation of 3D point cloud. We combine two techniques: gradient threshold segmentation, and mean height evaluation. Acquired 3D point cloud is represented as a graph data structures by exploiting the structure of 2D reference image. The ground parts nearing the position of the sensor are segmented based on gradient threshold technique. For sparse regions, we separate the ground and nonground by using a technique called mean height evaluation. The main contribution of this study is a new ground segmentation algorithm which works well with 3D point clouds from various environments. The processing time is acceptable and it allows the algorithm running in real time.

• The Journal of the Acoustical Society of Korea
• /
• v.43 no.5
• /
• pp.475-483
• /
• 2024

This paper examines the signal processing parameters of the field differencing method, a technique for estimating the source velocity or distance using a single receiver. The constraints that must be obeyed during the application of the field differencing method and the effect of the parameters on the velocity estimation performance were analyzed. Several cases identified in this study using the SWellEX-96 experiment data show that when applying the sound field differential technique, large errors may occur in the radial source velocity estimation results depending on parameter settings. The study confirmed that the influence of the processing parameters can vary depending on the signal frequency, and presented guidelines for selecting parameter values of the field differencing method for correct radial velocity estimation.

• Journal of the Korea Society of Computer and Information
• /
• v.28 no.4
• /
• pp.113-120
• /
• 2023

Smart farms are steadily increasing in research to minimize labor, energy, and quantity put into crops as IoT technology and artificial intelligence technology are combined. However, research on efficiently managing crop growth information in smart farms has been insufficient to date. In this paper, we propose a management technique that can efficiently monitor crop growth information by applying autonomous sensors to smart farms. The proposed technique focuses on collecting crop growth information through autonomous sensors and then recycling the growth information to crop cultivation. In particular, the proposed technique allocates crop growth information to one slot and then weights each crop to perform load balancing, minimizing interference between crop growth information. In addition, when processing crop growth information in four stages (sensing detection stage, sensing transmission stage, application processing stage, data management stage, etc.), the proposed technique computerizes important crop management points in real time, so an immediate warning system works outside of the management criteria. As a result of the performance evaluation, the accuracy of the autonomous sensor was improved by 22.9% on average compared to the existing technique, and the efficiency was improved by 16.4% on average compared to the existing technique.

• Journal of IKEEE
• /
• v.12 no.4
• /
• pp.217-224
• /
• 2008

This paper provides a framework for semantic correspondence of heterogeneous databases using self- organizing map. It solves the problem of overlapping between different databases due to their different schemas. Clustering technique using self-organizing maps (SOM) is tested and evaluated to assess its performance when using different kinds of data. Preprocessing of database is performed prior to clustering using edit distance algorithm, principal component analysis (PCA), and normalization function to identify the features necessary for clustering.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 1996.04a
• /
• pp.655-657
• /
• 1996

In this study, the methods and equipment that can be used to detail the anthropomorphic data were developed. This new method that utilizes the Moire' interferometry and image processing technique is less expensive than the conventional methods. We took 36 subjects (18 years to 28 years old). The face area was calculated based on contour information. The cluster analysis about those data enables us to classify our subjects into four groups.

• Korean Journal of Remote Sensing
• /
• v.6 no.1
• /
• pp.1-9
• /
• 1990

This paper presents a method of the constructing DEM(Digital Elevation Model) from the image data acquired from a commercial map using the scanner. Data acquistion, mark elimination, linking the broken line, elevation interpolation and 3D display processing are performed and the results are satisfatory.

• Journal of Digital Convergence
• /
• v.20 no.3
• /
• pp.325-331
• /
• 2022

As IoT devices are used in various ways in an edge network environment, multiple studies are being conducted that utilizes the information collected from IoT devices in various applications. However, it is not easy to apply accurate IoT data immediately as IoT data collected according to network environment (interference, interference, etc.) are frequently missed or error occurs. In order to minimize mistakes in IoT data collected in an edge network environment, this paper proposes a management technique that ensures the reliability of IoT data by randomly generating signature values of IoT data and allocating only Security Information (SI) values to IoT data in bit form. The proposed technique binds IoT data into a blockchain by applying multiple hash chains to asymmetrically link and process data collected from IoT devices. In this case, the blockchainized IoT data uses a probability function to which a weight is applied according to a correlation index based on deep learning. In addition, the proposed technique can expand and operate grouped IoT data into an n-layer structure to lower the integrity and processing cost of IoT data.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.8 no.8
• /
• pp.2691-2707
• /
• 2014

Medium access control is critical in wireless networks for efficient spectrum utilization. In this paper, we introduce a novel collision resolution method based on the technique of known interference cancellation, and propose a new MAC protocol named as CR-MAC, in which AP tries to decode all the collided data packets by combining partial retransmissions and known interference cancellation. As the collided transmissions are fully utilized, less retransmission is required, especially in a crowded network. The NS-2simulation and MATLAB numerical results show that, under various network settings, CR-MAC performs much better than the IEEE 802.11 DCF in terms of the aggregation throughput and the expected packet delay.

• Journal of Industrial Technology
• /
• v.10
• /
• pp.15-20
• /
• 1990

A parallel processing algorithm for discrete Kalman filter, which is one of the most commonly used filtering technique in modern control, signal processing, and communication, is proposed. Previously proposed parallel algorithms to decrease the number of computations needed in the Kalman filter are the hierachical structures by distributed processing of measurements, or the systolic structures to disperse the computational burden. In this paper, a new parallel Kalman filter employing a structure similar to recursive doubling is proposed. Estimated values of state variables by the new algorithm converge with two times faster data processing speed than that of the conventional Kalman filter. Moreover it maintains the optimality of the conventional Kalman filter.

• Annual Conference of KIPS
• /
• 2003.05b
• /
• pp.1125-1128
• /
• 2003

Increased use of PDA and Laptop has accelerated the development of wireless networking. With the tendency the need to support efficient and seamless data transmission technique has also been increased. However current mobility management protocol, such as the Mobile If, which is defined in RFC 2002, does not cover well these requirements. To satisfy these requirements, we should reduce Handoff processing time occurred by the movement of MN (Mobile Node) about the other networks. This paper proposes efficient Handoff mechanism on the new Mobile IP architecture using the Extended Macro that is a group organized with subnetworks, and sewed by a new added agent.