• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.6
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• pp.903-908
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• 2011

The purpose of this paper is to provider an indoor location measuring method, apparatus and Service available for mobile wireless network. This paper introduces positioning technology such as Basic Technology Element and QoS(Quality of Service) etc. of WPS(WiFi Positioning System) for mobile wireless network. An apparatus for sectionalizing an indoor area for indoor location measurement includes several steps. For example, a sector number input step, a sectionalization calculating step, a storing unit step etc. Also, This paper show advance Indoor positioning result.

• Journal of Korea Society of Digital Industry and Information Management
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• v.17 no.2
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• pp.1-11
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• 2021

Salt and pepper is a type of impulse noise. It may appear due to an error in the image transmission process and image storage memory. This noise changes the pixel value at any position in the image to 0 (in case of pepper noise) or 255 (in case of salt noise). In this paper, we present an algorithm for SAP noise reduction. The proposed method consists of three steps. In the first step, the location of the SAP noise is detected, and in the second step, the pixel value of the detected location is restored using a weighted average of the surrounding pixel values. In the last step, a reliability matrix around the reconstructed pixels is constructed, and additional correction is performed with a weighted average using this. As a result of the experiment, the proposed method appears to have similar or higher objective and subjective image quality than previous methods for almost all SAP noise ratios.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.9
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• pp.2056-2063
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• 2012

In a port terminal, containers are stored and transshipped by yard tractors and crane vehicles. For operation efficiency of the terminal, location information of these vehicles is an essential factor. However, most of port terminals try to estimate location of these assets using indirect methods such as event tracking of shipping or unshipping containers. Because these kinds of events are rarely occurred, location of the event includes seriously locating error compared to a real location of vehicle. In this paper, we propose a real-time asset tracking system to obtain accurate and reliable location of terminal assets. The proposed system overcomes a location estimation error caused by container stacks which interrupt wireless communication. In order to mitigate uncertainty and increase accuracy of location estimation, we designed hardwares and multi-step locating system to resolve additional preblems. We implemented system components, and installed these at a port environment for evaluation. The result shows superiority of the system that the accuracy is approximately 5.87 meters (CEP).

• Journal of the Korean Geographical Society
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• v.47 no.3
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• pp.426-439
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• 2012

The goal of this study is to propose a new method to capture the qualitative person spatial behavior. Beyond tracking or indexing the change of the location of a person, the changes in the relationships between a person and its environment are considered as the main source for the formal model of this study. Specifically, this paper focuses on the movement behavior of a person near the boundary of a region. To capture the behavior of person near the boundary of regions, a new formal approach for integrating an object's scope of influence is described. Such an object, a spatio-temporally extended point (STEP), is considered here by addressing its scope of influence as potential events or interactions area in conjunction with its location. The formalism presented is based on a topological data model and introduces a 12-intersection model to represent the topological relations between a region and the STEP in 2-dimensional space. From the perspective of STEP concept, a prototype analysis results are provided by using GPS tracking data in real world.

• ETRI Journal
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• v.29 no.1
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• pp.107-109
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• 2007

In location-based services, most trigger technologies have been implemented on the server side by periodically requesting the locations of mobile phones from mobile network servers. However, bottlenecks and communication interruptions occur when the servers are overloaded by trigger requests. In this letter, we propose a new multilevel location trigger specification which distributes the event detecting role to mobile phones and redesigns the location triggering into a multilevel step. Our suggested location trigger specification can reduce bottlenecks caused by triggers in a mobile core network and reduce power consumption caused by embedded GPS devices in mobile phones.

• Journal of Electrical Engineering and Technology
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• v.12 no.6
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• pp.2106-2117
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• 2017

An effective statistical feature extraction approach of data sampling of fault in the combined transmission system is presented in this paper. The proposed algorithm leads to high accuracy at minimum cost to predict fault location and fault type classification. This algorithm requires impedance measurement data from one end of the transmission line. Modal decomposition is used to extract positive sequence impedance. Then, the fault signal is decomposed by using discrete wavelet transform. Statistical sampling is used to extract appropriate fault features as benchmark of decomposed signal to train classifier. Support Vector Machine (SVM) is used to illustrate the performance of statistical sampling performance. The overall time of sampling is not exceeding 1 1/4 cycles, taking into account the interval time. The proposed method takes two steps of sampling. The first step takes 3/4 cycle of during-fault and the second step takes 1/4 cycle of post fault impedance. The interval time between the two steps is assumed to be 1/4 cycle. Extensive studies using MATLAB software show accurate fault location estimation and fault type classification of the proposed method. The classifier result is presented and compared with well-established travelling wave methods and the performance of the algorithms are analyzed and discussed.

• Journal of the Korean Society of Physical Medicine
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• v.10 no.3
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• pp.73-79
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• 2015

PURPOSE: This study aims to examine the impact of the location of a walker-aid pocket that is attached to the walker while walking. METHODS: The research subjects included 10 male adults and 10 elderly people. The subjects used a two-wheeled walker for the walking analysis, and a firm velcro-type pocket that can be attached to the walker aid was used for weight loading. The size of the external loads was set at 2kg, which corresponds to approximately 2.5% of the mean body weight of the subjects. The pocket was attached to the left, center, and right sides of the walker aid. Stride length, stride, step width, and time were investigated according to the location change. RESULTS: No statistical differences were observed in all the walking factors among the adults and elderly people regardless of the changes in the location of the walker pocket. In cases of no weight and the 2kg walker pocket, stride length and strides were longer for the adults, while the step width was greater and walking time was longer for the elderly people. CONCLUSION: The weight of the walker pocket turn out to retard walking speed, although the location of the walker pocket is not affect walking with the walker-aid.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.111.3-111
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• 2001

Automative system and robot are operated by motor. Recently, automative system and robot need correct operation and control for precise task. Therefore they need precise motor control technology. In present, controller needs precise motor control technology in automative system and robot. Usual step motor driver that has 200 steps per revolution is not proper. So we need micro step motor driver that is more precise then usual step motor driver. In this paper, micro step motor driver is used for precise control of step motor. The goal is precise operation and location control. This micro step motor driver is A3972SB that is made in Alloegro Company. It has serial port that receives two 6-bits linear DAC value. Almost all systems generate DAC value with micro processer and ...

• Proceedings of the Korean Information Science Society Conference
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• 2003.10c
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• pp.616-618
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• 2003

대부분의 Ad hoc 라우팅 프로토콜은 네트워크의 규모에 비례하여 경로 설정에 따른 오버헤드가 증가한다. 이에 반해 Geographic 라우팅 프로토콜은 노드의 지리적인 위치만을 이용하여 패킷을 forwarding하기 때문에 각각의 노드는 자신의 이웃 노드에 대한 정보만 유지하면 된다. 따라서 Geographic 라우팅 프로토콜이 큰 규모의 Ad hoc 네트워크 환경에 적합하다. 이러한 Geographic 라우팅은 목적지의 위치를 얻기 위해 Location service를 필요로 한다. 본 논문에서는 Geographic 라우팅 프로토콜을 큰 규모의 네트워크 환경에 적용할 수 있도록. 효율적인 Location service를 제공하는 TLD를 제안한다.

• Korean Journal of Remote Sensing
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• v.27 no.2
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• pp.99-105
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• 2011

This research presents the correction method to correct the location error of cloud caused by parallax error, and how the method can reduce the position error. The procedure has two steps: first step is to retrieve the corrected satellite zenith angle from the original satellite zenith angle. Second step is to adjust the location of the cloud with azimuth angle and the corrected satellite zenith angle retrieved from the first step. The position error due to parallax error can be as large as 60km in case of 70 degree of satellite zenith angle and 15 km of cloud height. The validation results by MODIS(Moderate-Resolution Imaging Spectrometer) show that the correction method in this study properly adjusts the original cloud position error and can increase the utilization of geostationary satellite data.