• Journal of Positioning, Navigation, and Timing
• /
• v.6 no.4
• /
• pp.211-221
• /
• 2017

Ellipsodially referenced survey (ERS) is considered as one of the challenging issues in the hydrographic surveys due to the fact that the bathymetric data collected by this technique can be readily transformed either to the geodetic or the chart datum by application of some geoscientific models. Global Navigation Satellite Systems (GNSS) is a preferred technique to determine the ellipsoidal height of a vessel reference point (RP) because it provides cost-effective and unprecedentedly accurate positioning solutions. Especially, the GNSS-derived heights include heave and dynamic draft of a vessel, so as for the reduced bathymetric solutions to be potentially free from these corrections. Although over the last few decades, differential GNSS (DGNSS) has been widely adopted in the bathymetric surveys, it only provides limited accuracy of the vertical component. This technical barrier can be effectively overcome by adopting the so-called GNSS carrier phase (CPH) based techniques, enhancing accuracy of the height solution up to few centimeters. From the positioning algorithm standpoint, the CPH-based techniques are categorized under absolute and relative positioning in post-processing mode; the former is precise point positioning (PPP) correcting errors by the global or regional models, the latter is post-processed kinematic positioning (PPK) that uses the differencing technique to common error sources between two receivers. This study has focused on assessment of achievable accuracy of the ellipsoidal heights obtained from these CPH-based techniques with a view to their applications to hydrographic surveys where project area is, especially, few tens to hundreds kilometers away from the shore. Some field trials have been designed and performed so as to collect GNSS observables on static and kinematic mode. In this paper, details of these tests and processed results are presented and discussed.

• Progress in Medical Physics
• /
• v.13 no.4
• /
• pp.218-223
• /
• 2002

Stereotactic radiosurgery for intracranial lesion is well established since the Lars Leksell first introduced radiosurgery concept in 1951 Its use in the treatment of spinal lesion has been limited by the availability of effective immobilization devices. The first clinical experience of the spinal stereotactic radiosurgery technique was reported by Hamilton AJ. in 1995. Recently, Optic-guided patient positioning technique for extracranial stereotactic radiosurgery was developed and reported. This study is for assess the target positioning accuracy of the optic guided patient positioning system Exactrac (BrainLab., Inc, Germany). We have designed phantom for assess the accuracy of spinal stereotactic radiosurgery The infrared reflective body markers attached to the relatively immobile part of the body and a series of 2 mm CT images was taken. The image sets were transferred to the planning computer. During the radiosurgery treatment, we measure the real-time display showing the positioning values from Exactrac computer. And we compare the isocenter deviation from irradiated center point of the film which was mounted on the lesion site of the phantom and pin hole site of that film. The accuracy of the ExacTrac system in positioning a target point shows enough for the clinical applications.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.41 no.10
• /
• pp.1197-1209
• /
• 2016

As Indoor Positioning System demands due to increased penetration and utilization of smart device, Indoor Positioning System using Wi-Fi or BLE(Bluetooth Low Energy) beacon takes center stage. In this paper, a terminal location of the user is calculated through Microscopic Trilateration using RSSI based on BLE. In the next step, a fingerprinting map appling approximate value of Microscopic Trilateration increases an efficiency of computation amount and energy for Indoor Positioning System. I suggest Indoor Positioning Algorithm based on BLE fingerprinting considering efficiency of energy by conducting precise Trilateration that assure user's terminal position by using AP(Access Point) surrounding targeted fingerprinting cells. And This paper shows experiment and result based on An Suggesting Algorithm in comparison with a fingerprinting based on BLE and Wi-Fi that be used for Indoor Positioning System.

• Proceedings of the KIEE Conference
• /
• 1997.11a
• /
• pp.89-91
• /
• 1997

Conventional linear control schemes often fail to provide precise positioning of a control object under the influence of friction, deadzone, saturation, etc. This paper proposes a control scheme for a precise point-to-point positioning system, which behaves well even under the above influences. The proposed scheme is composed of a fuzzy-neural controller. The neural network is employed to improve the performance of the fuzzy logic. To illustrate the effectiveness of this scheme, experiments are carried out for the cases of a fuzzy controller, the proposed fuzzy-neural controller, and the results are compared with each other.

• Journal of the Korean Society for Precision Engineering
• /
• v.23 no.7 s.184
• /
• pp.51-58
• /
• 2006

This study analyzes the uncertainty of the compensation method of a sensing error of three-DOF measuring system. This compensation method utilizes a reference coordinate system using a three point by moving a position of an endpoint of a three-DOF manipulator. The coordinate transformation between the three-DOF manipulator and the measuring system is identified by the reference coordinate system. According to the concept of this compensation method, each positioning error at any position of the end-point of the manipulator is derived. Uncertainty analyses of the compensation values on the basis of sensitivity analysis and Monte Carlo simulation are used to investigate a feasibility and effectiveness of the compensation method.

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 1995.10b
• /
• pp.211-217
• /
• 1995

Conventional linear control fails to provide precise positioning of a control object under the influence of friction, deadzone, saturation, etc. This paper proposes a high-precision control scheme for a precise point-to-point positioning system, called an X-Y table, even under the same influences above. The proposed scheme is composed of a fuzzy precompensator and a PD controller. The fuzzy precompensator is employed to improve the performance of the PD controller. Its fuzzy rules are obtained from experimental evolutionary programming (EP), not from an expert. The effectiveness of the scheme is demonstrated by experiments on the X-Y table. with a positioning error of within 1$\mu\textrm{m}$.

• Journal of Electrical Engineering and Technology
• /
• v.12 no.3
• /
• pp.1286-1291
• /
• 2017

In this paper, we propose an indoor positioning system that makes use of the attenuation model for IEEE 802.11 Channel State Information (CSI) in order to determine its distance from an Access Point (AP) at a fixed position. With the use of CSI, we can mitigate the problems present in the use of Received Signal Strength Indicator (RSSI) data and increase the accuracy of the estimated mobile device's location. For the experiments we performed, we made use of the Intel 5300 Series Network Interface Card (NIC) in order to receive the channel frequency response. The Intel 5300 NIC differs from its counterparts in that it can obtain not only the RSSI but also the CSI between an access point and a mobile device. We can obtain the signal strengths and phases from subcarriers of a system which in turn means making use of this data in the estimation of a mobile device's position.

• Korean Institute of Interior Design Journal
• /
• v.22 no.6
• /
• pp.40-48
• /
• 2013

Utilization of CCTV in crime prevention for public safety is accepted as the most effective measure in terms of crime prevention and control. Also, it is frequently used as a device that shows evidence of an unexpected situation or record on public social relationship. However, it is rare to find a study that qualitatively accessed the monitoring performance of a certain space depending on the choice and positioning of CCTVs. Thus, this study suggested a technology that can quantitatively compare and assess the monitoring performance of CCTVs depending on view angle and effective sight range of cameras as well as the monitoring performance depending on positioning measures. For the analysis, the concept of 3-dimensional surveillance field in the form of a frustum was suggested while deriving 3-dimensional range of sight and quantitative monitoring performance by applying Isovist theory. For the analysis technology, space of analysis subject, point of view (camera), and target point (measurement node) were installed at a 3-dimensional space and in use of ray-tracing algorithm, the line segment that was visually connected between the point of view and target point was extracted and accumulated. For such verification, analysis application was constructed and then applied to four alternative models on view angle and distance as well as four alternatives on positioning in order to verify its efficacy. Through the experiment, it was possible to compare and assess visibility depending on alternatives while quantifying the results by understanding the shadow areas beyond the monitoring range.

• Journal of IKEEE
• /
• v.18 no.4
• /
• pp.478-484
• /
• 2014

In this paper, we propose new algorithm for positioning of mouse cursor using fingertip direction on kinect depth camera. The proposed algorithm uses center of parm points from distance transform when fingertip point toward screen. Otherwise, algorithm use fingertip points. After image preprocessing, the center of parm points is calculated from distance transform results. If the direction of the finger towards the camera becomes close to the distance between the fingertip point and center of parm point, it is possible to improve the accuracy of positioning by using the center of parm point. After remove arm on image, the fingertip points is obtained by using a pixel on the long distance from the center of the image. To calculate accuracy of mouse positioning, we selected any 5 points. Also, we calculated error rate between reference points and mouse points by performed 500 times. The error rate results could be confirmed the accuracy of our algorithm indicated an average error rate of less than 11%.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.30 no.3
• /
• pp.249-258
• /
• 2012

In this study, the epoch adjustment model was developed to correct GPS precise point positioning result to be suitable for the current geodetic datum of Korea which is tied at past epoch statically. The model is based on the formula describing crustal movements, and the formula is composed of several parameters. To determine the parameters, the data gathered at 14 permanent GPS stations for 10 years, from 2000 to 2011, were processed using GIPSY-OASIS II. It was possible to determine the position of permanent GPS stations with an error range of 16mm and the position of check points with an error range of 12mm by appling the model to GPS precise point positioning result. It is considered that more precise model could be calculated by using GPS data of more permanent GPS stations.