• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.9
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• pp.208-214
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• 2014

Vehicle dynamic states used in various advanced driving safety systems are influenced by road geometry. Among the road geometry information, the vehicle pitch angle influenced by road slope and acceleration-deceleration is essential parameter used in pose estimation including the navigation system, advanced adaptive cruise control and others on sag road. Although the road slope data is essential parameter, the method measuring the parameter is not commercialized. The digital map including the road geometry data and high-precision DGPS system such as DGPS(Differential Global Positioning System) based RTK(Real-Time Kinematics) are used unusually. In this paper, low-cost cascade extended Kalman filter(CEKF) based road slope estimation method is proposed. It use cascade two EKFs. The EKFs use several measured vehicle states such as yaw rate, longitudinal acceleration, lateral acceleration and wheel speed of the rear tires and 3 D.O.F(Degree Of Freedom) vehicle dynamics model. The performance of proposed estimation algorithm is evaluated by simulation based on Carsim dynamics tool and T-car based experiment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.4C
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• pp.362-369
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• 2007

APSK (Amplitude Phase Shift Keying) digital modulation is characterized by the circular positioning of the transmission symbols in the constellation diagram. Due to such structural characteristics, the peak-to-average power ratio of the APSK modulation is lower than that of the QAM (Quadrature Amplitude Modulation), and the amount of performance degradation over nonlinear channels can be mitigated. The APSK modulation scheme has recently been adopted as satellite communication system standards including the DVB-S2 (Digital Video Broadcasting - Satellite, Version 2). In this paper, a BER (Bit Error Rate) upper bound approximation formula is derived using the channel model with the output power saturation characteristics, and its accuracy is demonstrated. Using the derived formula, the input power level that minimizes the BER is determined. The optimized performance based on the radii ratio of the 16APSK constellation and the channel saturation level is also presented.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.7
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• pp.550-557
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• 2017

Ionospheric delay, which affect the accuracy of GNSS positioning, is generated by electrons in Ionosphere. Solar activity level, region and time could make change of this delay level. Dual frequency receiver could effectively eliminate the delay using difference of refractive index between L1 to L2 frequency. But, Single frequency receiver have to use limited correction such as ionospheric model in standalone GNSS or PRC(pseudorange correction) in Differential GNSS. Generally, these corrections is effective in normal condition. but, they might be useless, when TEC(total electron content) extremely increase in local area. In this paper, monitoring algorithm is proposed for local ionospheric anomaly using multiple reference stations. For verification, the algorithm was performed with specific measurement data in Ionospheric storm day (20. Nov. 2003). this algorithm would detect local ionospheric anomaly and improve reliability of ionospheric corrections for standalone receiver.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.2
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• pp.149-157
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• 2009

Tracking technologies which provide real-time and customized information through various information collecting and processing for pedestrians who use traffic connective and transferring center have been being examined. However some problems are caused due to the wide-range positioning error for some services as device installation and service place. It is also difficult to be applied to traffic linkage and transfer services because many situations can be barren. In the testbed, Gwangmyoung Station, we got some results in bad conditions such as a lot of steel construction and another communication device. Practically, conditions of the place which will be built can be worse than Gwangmyoung station. Therefore, we researched suitable Location correction algorithm as a method for accuracy to traffic connective and transferring system. And its algorithm is designed through grid coordinates, map-matching, modeling coordinates and Kalman filtering and is being implemented continuously. Also preparing for optimization of various transferring center model, we designed for simulator type algorithm what is available for deciding algorithm factor.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.10
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• pp.13-19
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• 2007

Location awareness is one of the key functions to build U-city. Recently, many of works for location-aware systems are emerging to commercially apply to on-going large-scale apartment complex. As dwellers or cars being attached with active tags are moving in the U-city complex, the active tags periodically broadcast their own identifiers mu routers fixed along the street or in a building use those information to calculate location of thorn. There are several issues to be considered for such an environment. In this paper we propose i) a new architecture for location-aware system considering such issues ii) technical issues to implement it using active tags, and iii) a mathematical analytic model to investigate overall performance and verify it by comparing with actual experimental results. Through mathematical analysis, we can show that it is more efficient for the routers to send location signals than the tags do. We also show that there are several additional services available in the apartment complex. We conduscted several experiments hi a real ease parking lot to show that our system can locate the location of dwellers or cars.

• Journal of the Korean Society of Clothing and Textiles
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• v.23 no.1
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• pp.78-89
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• 1999

Clothes enhance visual images through the interaction between space and background of the wearer. The influence of background is important as that of the clothes when the observer understands the images. We look at fashion pictures used as important as that various backgrounds are presented depending on the image of the clothes. The clothing the model wears in the pictures takes on shape and space which supports the clothes. The background interact to from the whole image. The background has an important influence on the delivery of image for the clothes. However when the clothes are presented in the background there are some cases that all or parts of clothes can be shown. We must consider the composition ratio of the clothes and background which influences the whole image of the clothing. These interactions and influences on the whole image in regards to clothing background and the ratio will be the focus of this study. clothing was Modern Mannish Casual, Feminine, Ground was decided artificial setting 1 natural setting 1, indoor setting 1, artificial setting 2, natural setting 2, indoor setting 2, Percentage of Clothing was 80% , 140%, 200%,. Thus visual stimulus were 72 pictures that were combined Clothing Ground and Percentage of Clothing, the main survey of questionary consisted of their evaluation of the Picture image combined Clothing and Ground by 30 semantic differential bi-polar scales and the subjects were 50 students majoring in clothing and textile. The data analyzed by factor analysis MCA, MDS, The major finding were as follows : 1) As a result of factor analysis, 5 factors -Attractiveness Hardness and softness Cuteness Attention Cool and Warm factor were found out as constructing factors the Picture image combined Clothing and Ground 2) According to multidimensional positioning map were presented in a stimulus position the perceptive image differed in degree of similarity as a ground construction of stimulus in spite of same clothing image. It will aid in choosing the most beneficial background for any clothing brand. It will enhance the picture images to their full potential in any advertising medium.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.3
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• pp.292-300
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• 2011

Control systems in machinery equipment provide correction signals to motion units in order to reduce or cancel out the mismatches between sensor feedback signals and command or desired values. In this paper, we introduce a simulator for control characteristics of machinery equipment. The purpose of the simulator development is to provide mechanical system designers with the ability to estimate how much dynamic performance can be achieved from their design parameters and selected devices at the designing phase. The simulator has a database for commercial parts, so that the designers can choose appropriate components for servo controllers, motors, motor drives, and guide ways, etc. and then tune governing parameters such as controller gains and friction coefficients. The simulator simulates the closed-loop control system which is built and parameter-tuned by the designer and shows dynamic responses of the control system. The simulator treats the moving table as a 6 degrees-of-freedom rigid body and considers the motion guide blocks stiffness, damping and their locations as well as sensor locations. The simulator has been under development for one and a half years and has a few years to go before the public release. The primary achievements and features will be presented in this paper.

• Journal of the Korean Society of Radiology
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• v.11 no.7
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• pp.589-595
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• 2017

This study evaluated the effect of gadolinium contrast agents on the spectrum of metabolites during $^1H-MRS$ of brain and to investigate whether the contrast agents injected before MR spectroscopy significantly affect the estimated peaks of MRS. From January to May 2017, brain MR spectroscopy was performed on 30 patients to compare the spectrum before and after contrast injection of the brain white matter tissue. As a result, the spectrum of metabolites decreased after the paramagnetic contrast agents injected. However, it was not statistically significant which indicated that the use of contrast agent did not meaningfully affect the spectrum of metabolites. In conclusion, the use of the paramagnetic contrast before the acquisition of the spectroscopy may aid voxel positioning especially when it is difficult to determine the exact location of the lesion or the contrast is low.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.348-353
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• 2008

Despite the increasing popularity of wireless sensor network, indoor positioning using low power IEEE 802.15.4 compliant radio had attracted an interest of many researchers in the last decade. Old fashionable indoor location sensing information has been presented in dull and unpleasant 2D image standard. This paper focused on visualizing high precision 3 dimensional RSSI-based (received signal strength indication) spatial sensing information in an interactive virtual reality on PDA. The developed system operates by capturing and extracting signal strength information at multiple pre-defined reference nodes to provide information in the area of interest, thus updating user's location in 3D indoor virtual map. VRML (Virtual Reality Modeling Language) which specifically developed for 3D objects modeling is utilized to design 3D indoor environment.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11b
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• pp.124-131
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• 2000

In this study, the NEURAL NETWORK (hereinafter referred to as NN) was applied to control of the nonlinear factors for turning movement of the crawler vehicle and experiment was carried out using a small model of crawler vehicle in order to inspect an application of NN. Furthermore, CHAOS NEURAL NETWORK (hereinafter referred to as CNN) was also applied to this control so as to compare with conventional NN. CNN is especially effective for plane in many variables with local minimum which conventional NN is apt to fall into, and it is relatively useful to nonlinear factors. Experiment of turning on the slope of crawler vehicle was performed in order to estimate an adaptability of nonlinear problems by NN and CNN. The inclination angles of the road surface which the vehicles travel on, were respectively 4deg, 8deg, 12deg. These field conditions were selected by the object for changing nonlinear magnitude in turning phenomenon of vehicle. Learning of NN and CNN was carried out by referring to positioning data obtained from measurement at every 15deg in turning. After learning, the sampling data at every 15deg were interpolated based on the constructed learning system of NN and CNN. Learning and simulation programs of NN and CNN were made by C language ("Association of research for algorithm of calculating machine (1992)"). As a result, conventional NN and CNN were available for interpolation of sampling data. Moreover, when nonlinear intensity is not so large under the field condition of small slope, interpolation performance of CNN was a little not so better than NN. However, when nonlinear intensity is large under the field condition of large slope, interpolation performance of CNN was relatively better than NN.