• Proceedings of the Korea Multimedia Society Conference
• /
• 2012.05a
• /
• pp.83-85
• /
• 2012

Gait analysis through wearable sensors is becoming a key research topic in mobile. In gait analysis, step detection is one of the most important processes that will lay down the foundation for future implementation. In this paper, we will propose a simpler algorithm to determine and analyze the steps using accelerometer sensor built-in mobile phone that physically placed into the trouser pocket. This is the location where most of mobile devices are. With 5 volunteers walking in 160 seconds, the accuracy of this method is approximately 98.5%.

• Proceedings of the IEEK Conference
• /
• 2003.07e
• /
• pp.2092-2095
• /
• 2003

In this paper, we propose an algorithm to extract rectangular object area such 3s Data Matrix two-dimensional barcode using edge tracing-based linear feature detection. Hough transform is usually employed to detect lines of edge map. However, it requires parametric image space, and does not find the location of end points of the detected lines. Our algorithm detects end points of the detected lines using edge tracing and extracts object area using its shape information.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2009.10a
• /
• pp.991-994
• /
• 2009

This paper reports of camera detection of Mura. The type, location, size, orientation and amplitude are found. As the luminance variation in Mura is down to less than app. 0.3 %, measurement apparatus, techniques and algorithms are developed to measure low noise data and to extract the Mura from data with the residual noise in the same magnitude as the Mura.

• Journal of Internet Computing and Services
• /
• v.12 no.6
• /
• pp.73-82
• /
• 2011

The location-based service is emerging again to the public attention. The location recognition environment up-to-now has been studied with its focus only on a person, an object or a moving object. However, this study proposes a location recognition model that serves to recognize and track, in real time, multiple passengers in a moving vehicle. Identifying the locations of passengers can be classified into two classes: one is to use the high price terminal with GPS function, and the other is to use the economic price compact terminal without GPS function. Our model enables the simple compact terminal to provide effective location recognition under the on-boarding situation by transmitting messages through an interface device and sensor networks for a vehicle equipped with GPS. This technology reduces transmission traffic after detecting the condition of a vehicle (being parked or running), because it does not require transmission/receiving of information on the locations of passengers who are confined in a vehicle when the vehicle is running. Also it extends battery life by saving power consumption of the compact terminal. Hence, we carried out experiments to verify its serviceability by materializing the efficient tracking system for passengers with the detection algorithm of a stopping vehicle proposed in this study. Moreover, about 200 experiments using the system designed with this technology proved successful recognition on on-boarding and alighting of passengers with the maximum transmission distance of 12 km. In addition to this, the running recognition tests showed the test with the detection algorithm of a stopping vehicle has reduced transmission traffic by 41.6% compared to the algorithm without our model.

• Nuclear Engineering and Technology
• /
• v.54 no.8
• /
• pp.3006-3016
• /
• 2022

In this study, the images of specific prompt gamma (PG)-rays of 719 keV emitted from proton-boron reactions were analyzed using single-photon emission computed tomography (SPECT). Quantitative evaluation of the images verified the detection of anatomical changes in tumors, one of the important factors in daily adaptive proton therapy (DAPT) and verified the possibility of application of the PG-ray images to DAPT. Six scenarios were considered based on various sizes and locations compared to the reference virtual tumor to observe the anatomical alterations in the virtual tumor. Subsequently, PG-rays SPECT images were acquired using the modified ordered subset expectation-maximization algorithm, and these were evaluated using quantitative analysis methods. The results confirmed that the pixel range and location of the highest value of the normalized pixel in the PG-rays SPECT image profile changed according to the size and location of the virtual tumor. Moreover, the alterations in the virtual tumor size and location in the PG-rays SPECT images were similar to the true size and location alterations set in the phantom. Based on the above results, the tumor anatomical alterations in DAPT could be adequately detected and verified through SPECT imaging using the 719 keV PG-rays acquired during treatment.

• International conference on construction engineering and project management
• /
• 2022.06a
• /
• pp.328-335
• /
• 2022

With the advance of robot capabilities and functionalities, construction robots assisting construction workers have been increasingly deployed on construction sites to improve safety, efficiency and productivity. For close-proximity human-robot collaboration in construction sites, robots need to be aware of the context, especially construction worker's behavior, in real-time to avoid collision with workers. To recognize human behavior, most previous studies obtained 3D human poses using a single camera or an RGB-depth (RGB-D) camera. However, single-camera detection has limitations such as occlusions, detection failure, and sensor malfunction, and an RGB-D camera may suffer from interference from lighting conditions and surface material. To address these issues, this study proposes a novel method of 3D human pose estimation by extracting 2D location of each joint from multiple images captured at the same time from different viewpoints, fusing each joint's 2D locations, and estimating the 3D joint location. For higher accuracy, the probabilistic representation is used to extract the 2D location of the joints, considering each joint location extracted from images as a noisy partial observation. Then, this study estimates the 3D human pose by fusing the probabilistic 2D joint locations to maximize the likelihood. The proposed method was evaluated in both simulation and laboratory settings, and the results demonstrated the accuracy of estimation and the feasibility in practice. This study contributes to ensuring human safety in close-proximity human-robot collaboration by providing a novel method of 3D human pose estimation.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.27 no.5
• /
• pp.49-56
• /
• 2023

This study proposed a damage location estimation method for automated image-based port infrastructure inspection. Memory efficiency was improved by calculating the homography matrix using feature detection technology and outlier removal technology, without going through the 3D modeling process and storing only damage information. To develop an algorithm specialized for port infrastructure, the algorithm was optimized through ground-truth coordinate pairs created using images of port infrastructure. The location errors obtained by applying this to the sample and concrete wall were (X: 6.5cm, Y: 1.3cm) and (X: 12.7cm, Y: 6.4cm), respectively. In addition, by applying the algorithm to the concrete wall and displaying it in the form of an exterior damage map, the possibility of field application was demonstrated.

• Proceedings of the IEEK Conference
• /
• 2000.11d
• /
• pp.25-28
• /
• 2000

Gaze detection is to find out the position on a monitor screen where a user is looking at, using the computer vision processing. This System can help the handicapped to use a computer, substitute a touch screen which is expensive, and navigate the virtual reality. There are basically two main types of the study of gaze detection. The first is to find out the location by face movement, and the second is by eye movement. In the gaze detection by eye movement, we find out the position with special devices, or the methode of image processing. In this paper, we detect not the iris but the pupil from the image captured by Head-Mounted Camera with infra-red light, and accurately locate the position where a user looking at by A(fine Transform.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.26 no.8
• /
• pp.1599-1607
• /
• 2002

The purpose of this work is to suggest a new non-contact damage detection method for rotating ferromagnetic shafts. The presence and the location of a damage in rotating shafts are assessed by means of longitudinal elastic waves propagating along the shafts. These waves are measured by non-contact magnetostrictive sensors consisting of a coil and bias magnets. This paper shows the effectiveness of the sensors in the damage detection of rotating shafts. Several issues occurring in the application of the sensors to rotating shafts are carefully investigated.

• Proceedings of the KSRS Conference
• /
• 2005.10a
• /
• pp.126-129
• /
• 2005

Change detections is carried out under the assumption that pixel boundaries of geometrically corrected time series satellite images cover the same location. However that assumption can be wrong when shifts in the pointing direction of a satellite sensor occurs. Currently, although the influence of misregistration on landcover change detection has been investigated, there has been little research on the influence of pointing direction shifts of a satellite sensor. In this study, a simple method for reducing the effects of pointing direction shifts of a satellite sensor is proposed: the classification of two ASTER images was carried out using the linear spectral mixture analysis, the two classification results were resampled into a geometrically fixed grid, and then the change detection of the two ASTER images was carried out by comparing the resampled classification results of the two images. The proposed method showed high performance in discriminating between changed areas and unchanged areas by removing the pointing direction shifts of a satellite sensor.