• Aerospace Engineering and Technology
• /
• v.3 no.1
• /
• pp.242-250
• /
• 2004

This paper describes the detection method of wire-like obstacles using millimeter-wave radar system. Passive sensor like CCD camera can be used for the detection of high power electric cables on the hills or mountains and it can give very good quality of obstacle target information. But this system is very limited to use by bad weather condition. The detection capability for different diameters of wire targets using millimeter radar system have been accomplished. To simulate the target on the moving helicopter, rotating targets are used with fixed radar system. In the experiment 11mm, 16mm and 22mm diameter of wires have been detected in single, two and three wires in one position. The detected signal from single wire was very clear on gray level image. Three wires placed very closely together could be recognized in range, cross range image plane. For two and three wires, blur effect due to mutual scattering effect is observed.

• Journal of Digital Convergence
• /
• v.12 no.5
• /
• pp.263-269
• /
• 2014

Mobile Cloud Service will provide cloud services through mobile devices. Because storage space constraints and computing process performance limitations of mobile devices, this service will process in the cloud environment after moving works and data that have to process in mobile terminal. The obstacles of mobile cloud service activity will have concerned high about the reliability service, data security, and the confidentiality security. In particular, in convergence of mobile services and cloud services, each threats are expected to be generated complicatedly. In this paper, we define the type of mobile cloud services as well as security threats that can occur in mobile cloud. Also we suggest security countermeasures in mobile app. and enterprises countermeasures. We suggest verification of mobile applications for user information protection about security countermeasures in mobile app. Also we describe the cloud providers responsibility and user responsibility about enterprises countermeasures.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.21 no.1
• /
• pp.42-48
• /
• 2011

This paper presents the vibration reduction algorithm at the walking-will recognition sensors on the uneven terrain. Recently, concern about walking assistant aids is increasing according to the increase in population of elder and handicapped person. However, most of walking aids don't have any actuators for its movement. So, general walking aids have weakness for its movement to upward/download direction of slope. To overcome the weakness of the general walking aids, many researches for active type walking aids are being progressed. Especially, vibration analysis and impulse reduction are one of the important elements of the active-type walking aid during moving on the outdoor area because the ground has many kinds of obstacles such as speed dumps, puddles and so on. So, we analyze the influence from vibration by uneven terrain. And then, we propose the impulse reduction algorithm to overcome the vibration. All the processes are verified experimentally in an active-type walking aid.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.37 no.4B
• /
• pp.300-308
• /
• 2012

Many indoor location tracking technologies have been proposed. Generally indoor location tracking using TOA signal is used, there is a weak point that it's difficult to track the location due to obstacles like a refraction, reflection and dispersion of radio wave. In this paper, we apply ETOA(Estimated-TOA) algorithm in NLOS(Non-Line-Of-Sight) environment to solve above problem. In NLOS environment, TOA value between Beacon and Mobile node is predicted by ETOA algorithm and the tracking of indoor location is also possible to identify using two NLOS beacons of three beacons by this algorithm. We show that the proposed algorithm is accurate location tracking is accomplished using the applying the proposed algorithm to indoor moving robot and the inertia sensor of robot and Kalman filter algorithm.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.18 no.11
• /
• pp.2721-2726
• /
• 2014

In a MOG algorithm using the GMM to subtract background, the model parameter computation and the object classification to be performed at every pixel require a huge computation and are the chief obstacles to its uses. This paper proposes a fast MOG algorithm that partly adopts the simple model parameter computation and the object classification skip on the basis of the object prediction. The former is applied to the pixels that gives little effect on the model parameter and the latter is applied to the pixels whose object prediction is firmly trusted. In comparative experiment between the conventional and proposed algorithms using videos, the proposed algorithm carries out the simple model parameter computation and the object classification skip over 77.75% and 92.97%, respectively, nevertheless it retains more than 99.98% and 99.36% in terms of image and moving object-unit average classification accuracies, respectively.

• Journal of the Korean Society for Precision Engineering
• /
• v.30 no.1
• /
• pp.47-52
• /
• 2013

In order to operate a search and rescue robot in hazardous area, the robot requires high mobility and adaptable locomotion for moving in unpredictable environments. In this paper, we propose the deformable soft wheel robot that can produce three kinds of driving modes; caterpillar driving mode, normal wheel driving mode, legged-wheel driving mode. The robot changes its driving mode as it faces the various obstacles such as a small gap, stairs etc. Soft film and composite materials are used for fabrication of deformable wheel structure and Shape Memory Alloy (SMA) coil spring actuators are attached on the structure as an artificial muscle. Film lamination and an composite manufacturing process is introduced and the robot design is required to be modified and compromised to applying the manufacturing process. The prototype is developed and tested for verifying feasibility of the deformable wheel locomotion.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.25 no.6
• /
• pp.785-791
• /
• 2021

In this paper, we propose a methodology for estimating the optimal traversable destination from the location-based information of the object recognized by the mobile robot to perform the object delivery service. The location estimation process is to apply the generalized Voronoi graph to the grid map to create an initial topology map composed of nodes and links, recognize objects and extract location data using RGB-D sensors, and collect the shape and distance information of obstacles. Then, by applying the hybrid approach that combines the center of gravity and thinning method, the optimal moving position for the service robot to perform the task of grabbing is estimated. And then, the optimal node information for the robot's work destination is updated by comparing the geometric distance between the estimated position and the existing node according to the node update rule.

• The Journal of the Convergence on Culture Technology
• /
• v.9 no.4
• /
• pp.569-576
• /
• 2023

An agricultural drones are gradually increasing in utilization due to economic efficiency, and consist of a main frame in charge of flying spray system in charge of moving pesticide to control targets. Therefore, the environment and characteristics of crops should be considered when controlling pesticides using drones and conditions such as systematic flying altitude of flight, speed, and spray time should be changed accordingly. However, pest control work using agricultural drones has different spray effects depending on level the operation proficiency and spray impact. In addition, there are variations in operating standards and control efficiency for agricultural drones, which hinder the distribution of agricultural control drones in the field of pest control work. Therefore, this study attempts to identify the spraying characteristics of agricultural drones, apply the effective spraying time, interval and experimentally verify the system that can calculation of spray area compared to previous studies. Through this experimental verification, it is intended to apply the optimal control process by minimizing the obstacles to pest control work by applying the operation method and systematic figures to agricultural drones.

• The Journal of Korean society of community based occupational therapy
• /
• v.9 no.2
• /
• pp.23-31
• /
• 2019

Objective : The purpose of this study is to repeatedly conduct task-oriented training in scopolamine-induced dementia rats and as a result observe changes in the content of acetylcholine, a marker of cognitive function and central nervous system plasticity, to identify the improvement effect of dementia. Methods : It consisted of two groups. One group I was that did not perform task-oriented training in scopolamine-induced dementia rats and the other group II was that performed task-oriented training. Task-oriented training involved stretching, grasping and moving arms and walking obstacles on the legs. We performed a quantified passive avoidance test in the measurement of memory for cognitive function and compared the change in the content of acetylcholine for the plasticity of the central nervous system. Results : The results of the study are as follows: First, there was a significant improvement in cognitive function since the 4th days after task-oriented training of scopolamine-induced dementia rats(.00). Second, task-oriented training applied to scopolamine-induced dementia rats showed a significant increase in acetylcholine content. Conclusion : In this study, task-oriented training, which is often performed on senile dementia patients during occupational therapy intervention, was scientifically demonstrated in scopolamine-induced dementia rats by enhancement of cognitive function through memory improvement and increase in the content of acetylcholine confirming central nervous system plasticity.

• Journal of Korea Multimedia Society
• /
• v.9 no.11
• /
• pp.1483-1495
• /
• 2006

The navigation mesh represents a terrain as a set of triangles on which characters may move around. The navigation mesh cab be generated automatically, and it is more flexible in representing 3D surface. The number of triangles to represent a terrain may vary according to the structure of the terrain. As characters are moving around on a navigation mesh, the path planning can be performed more easily by projecting the 3D surfaces into 2D space. However, when the terrain is represented with an elaborated mesh of large number of triangles to achieve more realistic movements, the path finding can be very inefficient because there are too many states(triangles) to be searched. In this paper, we propose an efficient method of path finding in 3D games where the terrain is represented by navigation meshes. Our method uses the visibility tests. When the graph-based search is applied to elaborated polygonal meshes for detailed terrain representation, the path finding can be very inefficient because there are too many states(polygons) to be searched. In our method, we reduce the search space by using visibility tests so that the search can be fast even on the detailed terrain with large number of polygons. First we find the visible vertices of the obstacles, and define the heuristic function as the distance to the goal through those vertices. By doing that, the number of states that the graph-based search visits can be substantially reduced compared to the plane search with straight-line distance heuristic.