• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.5
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• pp.70-81
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• 2020

Point-by-point data, which is abundantly collected by vehicles with embedded GPS (Global Positioning System), generate useful information. These data facilitate decisions by transportation jurisdictions, and private vendors can monitor and investigate micro-scale driver behavior, traffic flow, and roadway movements. The information is applied to develop app-based route guidance and business models. Of these, speed data play a vital role in developing key parameters and applying agent-based information and services. Nevertheless, link speed values require different levels of physical storage and fidelity, depending on both collecting and reporting intervals. Given these circumstances, this study aimed to establish an appropriate collection interval to efficiently utilize Space Mean Speed information by vehicles with embedded GPS. We conducted a comparison of Probe-vehicle data and Image-based vehicle data to understand PE(Percentage Error). According to the study results, the PE of the Probe-vehicle data showed a 95% confidence level within an 8-second interval, which was chosen as the appropriate collection interval for Probe-vehicle data. It is our hope that the developed guidelines facilitate C-ITS, and autonomous driving service providers will use more reliable Space Mean Speed data to develop better related C-ITS and autonomous driving services.

• KIPS Transactions on Computer and Communication Systems
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• v.7 no.8
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• pp.195-202
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• 2018

With the development of location-based applications such as smart phones and GPS navigation, active research is being conducted to protect location and trajectory privacy. To receive location-related services, users must disclose their exact location to the server. However, disclosure of users' location exposes not only their locations but also their trajectory to the server, which can lead to concerns of privacy violation. Furthermore, users request from the server not only location information but also multimedia information (photographs, reviews, etc. of the location), and this increases the processing cost of the server and the information to be received by the user. To solve these problems, this study proposes the EGTC (Enhanced Grid-based Trajectory Cloaking) technique. As with the existing GTC (Grid-based Trajectory Cloaking) technique, EGTC method divides the user trajectory into grids at the user privacy level (UPL) and creates a cloaking region in which a random query sequence is determined. In the next step, the necessary information is received as index by considering the sub-grid cell corresponding to the path through which the user wishes to move as c(x,y). The proposed method ensures the trajectory privacy as with the existing GTC method while reducing the amount of information the user must listen to. The excellence of the proposed method has been proven through experimental results.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.42 no.5
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• pp.243-250
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• 2016

Objectives: Many studies have examined histopathological factors and various prognostic scores related to inflammation to predict outcomes. Here, we examined the prognostic value of the C-reactive protein/albumin (CRP/alb) ratio in oral squamous cell carcinoma (OSCC). Materials and Methods: This retrospective study included 40 patients with OSCC. Using univariate and multivariate analyses, we focused on the correlation of the CRP/alb ratio with clinicopathological characteristics and with overall survival. We then compared five inflammation-based prognostic scores, CRP/alb ratio, modified Glasgow Prognostic Score (mGPS), neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), and prognostic nutritional index (PNI), based on receiver operating characteristic (ROC) curves. Results: The optimal cut-off value for the CRP/alb ratio was 0.085. The group with a high CRP/alb ratio had a high TNM clinical stage (P=0.002) and larger primary tumors (P=0.029), with statistically significant differences in lymph node metastasis and distant metastasis. In addition, when the CRP/alb ratio was high, multivariate analysis showed a lower survival rate (P=0.002; hazard ratio=6.078), and the ROC curve showed more outstanding discriminatory ability regarding overall survival compared to other inflammation-based prognostic scores. Conclusion: The CRP/alb ratio can be an independent prognostic factor when predicting prognosis in OSCC and has good prognostic ability.

• International Journal of Automotive Technology
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• v.7 no.4
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• pp.509-517
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• 2006

In the mid 1990s, the combination of vehicles and communication was expected to bolster the stagnant car industry by offering a flood of new revenues. In-vehicle computing systems provide safety and control systems needed to operate the vehicle as well as infotainment, edutainment, entertainment, and mobile commerce services in a safe and responsible manner. Since 1980 the word "telematics" has meant the blending of telecommunications and informatics. Lately, telematics has been used more and more to mean "automotive telematics" which use informatics and telecommunications to enhance the functionality of motor vehicles such as wireless data applications, intelligent cruise control, and GPS in vehicles. This definition identifies telecommunications transferring information as the key enabling technology to provide these advanced services. In this paper, a possible framework for future telematics, which called an Intelligent Vehicle Network(IVN), is proposed. The paper also introduces and compares a number of existing technologies and the terms of their capabilities to support a suite of services. The paper additionally the paper suggests and analyzes possible directions for future telematics from current telematics techniques.

• Journal of the Korean Institute of Navigation
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• v.15 no.4
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• pp.1-11
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• 1991

Since it is very important for an ocean-going vessel to transmit information quickly and accurately to her owner or charterer not only for the ship's safety but for economic operation of the ship, some newly-built automated vessels equipped with automatic information transmission system which consists of INMARSAT-C and specially-designed computer. This system, however, is not applicable to the existing vessel without chaging her equipments and, furthermore, is too expensive for small shipping companies to fit out such a system on their vessels. Therefore, we propose a low-priced information transmission system which consists of a personal computer and communication equipments in the existing vessel, and in this paper, as the groundwork of the proposed system, we have made up the ship's position transmission system which is composed of and IBM AT-compatible, PC, INMARSAT-A and a GPS receiver. As the test result of the system through sea trial on the training ship 'HANBADA', we confirmed that transmission of the ship's position was achieved succesfully and consequently there could be high possibility of cost-effectiveness of the proposed system.

• Ocean Systems Engineering
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• v.9 no.4
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• pp.391-407
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• 2019

Tracking the location (position) of a surface or underwater marine vehicle is important as part of guidance and navigation. While the Global Positioning System (GPS) works well in an open sea environment but its use is limited whenever testing scaled-down models of such vehicles in the laboratory environment. This paper presents the design, development and implementation of a low energy ultrasonic augmented single beacon-based localization technique suitable for such requirements. The strategy consists of applying Extended Kalman Filter (EKF) to achieve location tracking from basic dynamic distance measurements of the moving model from a fixed beacon, while on-board motion sensor measures heading angle and velocity. Iterative application of the Extended Kalman Filter yields x and y co-ordinate positions of the moving model. Tests performed on a free-running ship model in a wave basin facility of dimension 30 m by 30 m by 3 m water depth validate the proposed model. The test results show quick convergence with an error of few centimeters in the estimated position of the ship model. The proposed technique has application in the real field scenario by replacing the ultrasonic sensor with industrial grade long range acoustic modem. As compared with the existing systems such as LBL, SBL, USBL and others localization techniques, the proposed technique can save deployment cost and also cut the cost on number of acoustic modems involved.

• Korean Journal of Geomatics
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• v.4 no.2
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• pp.59-65
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• 2004

Recently, a lot of interest focuses on DGPS with which it is possible to obtain 3D geographic information in real time. There are some methods to transmit corrected signals which use ground based systems as beacon, as well as wireless and TV broadcasting media. However, these methods require a large number of stations. Therefore, when the distance from station to user is increased, there is a range limit to the transmission of corrected signals. In order to solve these problems, WADGPS method using Geo-satellite is being investigated. In this study, static and kinematic tests were performed by using Satloc SLX WADGPS and Ashtech receivers. The results showed that SA was affected most among corrected signals of WADGPS; it was followed by ionospheric delay, tropospheric delay and satellite orbit errors. The accuracy of static observation was approx. $\pm$1m on SA-on. This was ten times as accurate as that of absolute observation by common receiver on SA-off. In the SA-off, the accuracy of WADGPS can be improved further. The result of kinematic tests by WADGPS acted in concert with that of standard DGPS by C/A code. It was concluded that the application of W ADGPS could improve considerably navigation and the construction of geographic information.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.375-381
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• 2022

Safety accidents are of concern during construction projects, even given the recent innovations in digital technologies. These projects remain focused on overcoming specific and limited applications on construction sites. For this reason, the development of an inclusive safety management system has become crucial. This study aims to build a Big Data platform to inform decisions on how to proactively eliminate worker hazards on construction sites. The platform consists of about 100,000 real records and a real-time monitored database featuring various safety indices, such as workers' altitudes, heart rates, and fatigability during construction, which are determined through various wearable devices. The data types are customized and integrated by a research team in accordance with the characteristics of a specific project using hypertext transfer protocol (HTTP). The results can be helpful as efficient tools to ensure successful safety management in complex construction situations. This study is expected to provide three significant contributions to the field, including real-time fatigability analysis and tracking of workers on-site; providing early GPS-based warnings to workers who might be accessing dangerous spaces or places; and monitoring the workers' health indices, based on details from 100,000 cases.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.3
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• pp.278-287
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• 2013

Modern information technologies continue to provide industries with new and improved methods. With the rapid development of Machine to Machine (M2M) communication, a smart container supply chain management is formed based on high performance sensors, computer vision, Global Positioning System (GPS) satellites, and Globle System for Mobile (GSM) communication. Existing supply chain management has limitation to real time container tracking. This paper focuses on the studies and implementation of real time container chain management with the development of the container identification system and automatic alert system for interrupts and for normal periodical alerts. The concept and methods of smart container modeling are introduced together with the structure explained prior to the implementation of smart container tracking alert system. Firstly, the paper introduces the container code identification and recognition algorithm implemented in visual studio 2010 with Opencv (computer vision library) and Tesseract (OCR engine) for real time operation. Secondly it discusses the current automatic alert system provided for real time container tracking and the limitations of those systems. Finally the paper summarizes the challenges and the possibilities for the future work for real time container tracking solutions with the ubiquitous mobile and satellite network together with the high performance sensors and computer vision. All of those components combine to provide an excellent delivery of supply chain management with outstanding operation and security.

• Journal of Navigation and Port Research
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• v.34 no.8
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• pp.603-607
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• 2010

The LORAN system had been used widely and it was an essential navigation aid for ships in the ocean until the GPS is adopted actively. In particular, it was essential functionality for the ships to sail the oceans. According to the advancement of industry, however, the current accuracy of traditional Loran is insufficient for the utilization of harbour approach, land navigation, and the field of survey and timing. Therefore it is necessary that the study on the improvement of the positioning accuracy of Loran. The one of the improving methods is to measure and compensate the propagation time delay between the transmitter and user's receiver, which is called as additional secondary factor (ASF). In this study, we measured the ASF between the Pohang master transmitting station (9930M) and four points where locate within 33 km apart from the transmitting station, using the measuring technique of the absolute time delay without a time of coincidence (TOC) table. As the result of measurement, the ranging error caused by the propagation delay was about 210 m at 33 km, however it can be reduced up to 40 m with ASF compensation.