• IEMEK Journal of Embedded Systems and Applications
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• v.15 no.5
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• pp.215-225
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• 2020

Light detection and ranging (LiDAR) sensors detect the distance of the surrounding environment and objects. Conventional LiDAR sensors require a certain amount of a power because they detect objects by transmitting lasers at a regular interval depending on a constant resolution. The constant power consumption from operating multiple LiDAR sensors is detrimental to autonomous and electric vehicles using battery power. In this paper, we propose two algorithms that improve the inefficient power consumption during the constant operation of LiDAR sensors. LiDAR sensors with algorithms efficiently reduce the power consumption in two ways: (a) controlling the resolution to vary the laser transmission period (T_P) of a laser diode (LD) depending on the vehicle's speed and (b) reducing the static power consumption using a sleep mode depending on the surrounding environment. A proposed LiDAR sensor with a resolution control algorithm reduces the power consumption of the LD by 6.92% to 32.43% depending on the vehicle's speed, compared to the maximum number of laser transmissions (N_x·max). The sleep mode with a surrounding environment-sensing algorithm reduces the power consumption by 61.09%. The proposed LiDAR sensor has a risk factor for 4-cycles that does not detect objects in the sleep mode, but we consider it to be negligible because it immediately switches to an active mode when a change in surrounding conditions occurs. The proposed LiDAR sensor was tested on a commercial processor chip with the algorithm controlling the resolution according to the vehicle's speed and the surrounding environment.

• The KIPS Transactions:PartD
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• v.19D no.3
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• pp.221-228
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• 2012

This paper proposes a new forging work-in-process control system that guarantees independency of a specific device and provides cost-effectiveness. Until now, much research has been studied on improving the process productivity through efficient work-in-process or inventory controls. Especially, incorporating various IT technologies such as barcode, RFID, and image recognition has been done. However, those approaches cause many problems due to the characteristics of the forging work-in-process control environment. To overcome the limitations of the existing approaches, this paper proposes a novel forging work-in-process control system. The proposed system in this paper identifies and precisely manages positions of objects by using GPS information of smart mobile devices. Therefore, identification tags as well as specific devices for reading the tags do not been required. It resolves the problems of the previous approaches and enhances the productivity of the overall forging work-in-process control process.

• Korean Journal of Computational Design and Engineering
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• v.5 no.3
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• pp.255-262
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• 2000

A computer-aided process planning (CAPP) system for rotationally symmetric deep drawing products has been developed. The application for non-axisymmetric components, however, has not been reported yet. Therefore, this study investigates process sequence design in deep drawing process and constructs an expert system of process planning for non-axisymmetric motor frame products with elliptical shape. The system developed consists of four modules. The first one is recognition of shape module to recognize the products. The second one is a 3-D modeling module to calculate surface area for non-axisymmetric products. The third one is a blank design module that creates an oval-shaped blank with the identical surface area. The forth one is a process planning module based on production rules that play the best important role in an expert system for manufacturing. The production rules are generated and upgraded by interviewing with field engineers. The constructed system using AutoLISP language under the AutoCAD environment is baled on the knowledge base system which is involved a lot of expert's technology. Results of this system will be provide effective aids to the designer and engineer in this field.

• Journal of Korea Multimedia Society
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• v.14 no.2
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• pp.171-181
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• 2011

A vision-based method for positioning and orienting of pallets is presented in this paper, which guides autonomous forklifts to engage pallets automatically. The method uses a single camera mounted on the fork carriage instead of two cameras for stereo vision that is conventionally used for positioning objects in 3D space. An image back-projection technique for determining the orient of a pallet without any fiducial marks is suggested in tins paper, which projects two feature lines on the front plane of the pallet backward onto a virtual plane that can be rotated around a given axis in 3D space. We show the fact that the rotation angle of the virtual plane on which the back-projected feature lines are parallel can be used to describe the orient of the pallet front plane. The position of the pallet is determined by using ratio of the distance between the back-projected feature lines and their real distance on the pallet front plane. Through a test on real pallet images, we found that the proposed method was applicable to real environment practically in real-time.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.40 no.2
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• pp.91-108
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• 2022

In most cases, optical images have been used as training data of DL (Deep Learning) models for object detection, recognition, identification, classification, semantic segmentation, and instance segmentation. However, properties of 3D objects in the real-world could not be fully explored with 2D images. One of the major sources of the 3D geospatial information is DSM (Digital Surface Model). In this matter, characteristic information derived from DSM would be effective to analyze 3D terrain features. Especially, man-made objects such as buildings having geometrically unique shape could be described by geometric elements that are obtained from 3D geospatial data. The background and motivation of this paper were drawn from concept of the intrinsic image that is involved in high-level visual information processing. This paper aims to extract buildings after classifying terrain features by training DL model with DSM-derived information including slope, aspect, and SRI (Shaded Relief Image). The experiments were carried out using DSM and label dataset provided by ISPRS (International Society for Photogrammetry and Remote Sensing) for CNN-based SegNet model. In particular, experiments focus on combining multi-source information to improve training performance and synergistic effect of the DL model. The results demonstrate that buildings were effectively classified and extracted by the proposed approach.

• The Journal of the Korea Contents Association
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• v.18 no.3
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• pp.11-18
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• 2018

To interact with a virtual object in immersive virtual environment, the target object should be selected quickly and accurately. Conventional 3D ray casting method using a direction of user's hand or head allows the user to select an object quickly. However, accuracy problem occurs when selecting an object using conventional methods among occlusion of objects. In this paper, we propose a region of interest based selection method that enables to select an object among occlusion of objects using a combination of gaze tracking and hand gesture recognition. When a user looks at a group of occlusion of objects, the proposed method recognizes user's gaze input, and then region of interest is set by gaze input. If the user wants to select an object among them, the user gives an activation hand gesture. Then, the proposed system relocates and visualizes all objects on a virtual active window. The user can select an object by a selecting hand gesture. Our experiment verified that the user can select an object correctly and accurately.

• International Journal of Internet, Broadcasting and Communication
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• v.9 no.3
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• pp.1-8
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• 2017

Recently, the development of the head mounted display (HMD) device has attracted a great deal of attention to the actual contents. Especially, Augmented Reality (AR), which is a mixture of actual information and virtual world information, is focused on. AR HMD is able to interact by arranging virtual objects in real space through spatial recognition using depth camera. In order to naturally mix virtual space with real space, it is necessary to develop a technology for realizing spatial mapping information with high accuracy. The purpose of this paper is to evaluate the optimal configuration of augmented reality application program by realizing accurate spatial mapping information when mapping a real space and an object placement environment using HoloLens. To do this, we changed the spatial mapping information in real space to three levels, which are the number of meshes used in cubic meters to scan step by step. After that, it was compared with the 3D model obtained by changing the actual space and mesh number. Experimental result shows that the higher the number of meshes used in cubic meters, the higher the accuracy between real space and spatial mapping. This paper is expected to be applied to augmented reality application programs that require scanning of highly mapped spatial mapping information.

• Journal of Korean society of Dental Hygiene
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• v.9 no.2
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• pp.207-220
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• 2009

This study researched into literature materials in order to utilize basic data on job importance in dental coordinator, and analyzed questionnaire on job importance in dental coordinator for about 2 months from August and September in 2008 targeting dental hygienists and other manpower for dental hospitals & clinics where are located in D region and neighboring region. The following are the results: 1. Dental hospital & clinics where dental coordinators work were surveyed to be totally 66.9%. Dental coordinators were indicated to be 71.1% as for dental hospital$^{\circ}{\S}$clinic(women), and to be 28.4% as for a case with none. There was significant difference according to final academic degree and working place(P<.001). 2. License holders(women) for dental hygienist as dental coordinator accounted for 39.8%. The opposite case accounted for 60.2%. A case of doing duty of dental coordinator given not dental hygienist was indicated to be high. There was significant difference according to working place(p<.01). 3. The task importance on job that a dental coordinator directly performs was indicated to be averagely 3.24, thereby having been recognized to be important. 4. As for the recognition on job importance according to working-year number, it was indicated to have higher recognition on task importance in the more working-year number regarding customer management(p<.01), organization management(p<.05), and self-management(p<.01). 5. Given seeing difference in recognition on task importance according to medical institution, it was indicated to be 3.34 for dental clinic and 3.25 for dental hospital. Thus, the task importance was indicated to be slightly high in a person who works for dental clinic. There was no significant difference. In light of the above results, in order to educate dental coordinator who can successfully perform a role at dental hospital & clinic, a dental hygienist is required who is equipped with dental-clinic career rather than a person without a major. A professionally educational program for dental coordinator needs to be developed. Even in a dental coordinator's task, there is necessity for the curricular development and the specialized education.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.327-332
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• 2017

As Internet of Things (IoT) technology advances, there is a growing demand for location-based services (LBSs) to identify users' mobility and identity. The initial LBS system was mainly used to measure position information by measuring the phase of a signal transmitted from a global positioning system (GPS) satellite or by measuring distance to a satellite by tracking the code of a carrier signal. However, the use of GPS satellites is ineffective, because it is difficult to receive satellite signals indoors. Therefore, research on wireless communications systems like ultra-wide band (UWB), radio frequency identification (RFID), and ZigBee are being actively pursued for location recognition technology that can be utilized in an indoor environment. In this paper, we propose an LBS system that includes the 2.45GHz band for chirp spread spectrum (CSS), and the 3.1-10.6GHz band and the 250-750MHz bands for UWB using the IEEE 802.15.4a standard for low power-based location recognition. As a result, we confirmed that the 2.45GHz Industrial, Scientific and Medical (ISM) band RF transceiver and the ranging function can be realized in the hardware and has 0dBm output power.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.11
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• pp.1029-1035
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• 2013

This paper proposes a real time lane detection algorithm using LRF (Laser Range Finder) for autonomous navigation of a mobile robot. There are many technologies for safety of the vehicles such as airbags, ABS, EPS etc. The real time lane detection is a fundamental requirement for an automobile system that utilizes outside information of automobiles. Representative methods of lane recognition are vision-based and LRF-based systems. By the vision-based system, recognition of environment for three dimensional space becomes excellent only in good conditions for capturing images. However there are so many unexpected barriers such as bad illumination, occlusions, and vibrations that the vision cannot be used for satisfying the fundamental requirement. In this paper, we introduce a three dimensional lane detection algorithm using LRF, which is very robust against the illumination. For the three dimensional lane detections, the laser reflection difference between the asphalt and lane according to the color and distance has been utilized with the extraction of feature points. Also a stable tracking algorithm is introduced empirically in this research. The performance of the proposed algorithm of lane detection and tracking has been verified through the real experiments.