• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.77-82
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• 2006

Integrity plays a fundamental role in the feasibility of 'liability critical' applications. Road charging, e.g. road tolling in urban zones or on highways, represents a series of liability critical applications where a guarantee in integrity could be a true enabler: being the mechanism that prevents the incorrect charging of users and enabling the advancement of these applications using GNSS such as Galileo and EGNOS that provide integrity mechanisms. However, the integrity of the end user position is not guaranteed by the EGNOS and Galileo integrity services alone as provided. Algorithms have been developed to supply a guarantee on the performance attainable at the user level through the provision of a horizontal protection level that responds to local user conditions such as multipath or interference. In addition, an application has been developed that implements road charging mechanisms based on the availability of user-level integrity. Results obtained show that the user-level integrity algorithms provided the required level of integrity guarantee and granularity of the horizontal protection levels necessary for executing urban and rural (highway) road charging. In addition, the road charging application developed shows that the current application domain requirements can be met through the provision of guaranteed integrity and that further reductions in the horizontal protection levels along with increased signal availability will enable future road charging modalities.

• Journal of Positioning, Navigation, and Timing
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• v.12 no.3
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• pp.281-288
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• 2023

The International Maritime Organization (IMO) states that the recommended horizontal accuracy for coastal and offshore areas is 10 m, the Alert Limit (AL) is 25 m, the time to alert is 10 seconds, and the integrity risk (IR) is 10^-5 per three hours. For operations requiring high accuracy, such as tugs and pushers, icebreakers, and automated docking, the IMO dictates that a high level of positioning accuracy of less than one meter and a protection level of 0.25 meters (for automated docking) to 2.5 meters should be achieved. In this paper, we analyze a method of calculating the user-side protection level of the centimeter-level precision Global Navigation Satellite System (GNSS) that is being studied to provide augmentation information for the precision Positioning, Navigation and Timing (PNT) service. In addition, we analyze standardized integrity forms based on RTCM SC-134 to propose an integrity information form and generate a centimeter-level precise PNT service plan.

• Korean Journal of Heritage: History & Science
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• v.46 no.3
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• pp.32-47
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• 2013

The concepts of authenticity and integrity are very important standards to be satisfied in the conservation and utilization of Scenic Site (名勝), literally meaning the places of scenic beauty, as a public heritage. These concepts, which are frequently used in the conservation and utilization of the World Heritage inscribed by UNESCO, can be applied to all kinds of heritages. Recently, it has been widely recognized that the concepts of authenticity and integrity are not separable but interconnected. Accordingly, the maintenance of authenticity in Scenic Site should include not only the physical preservation but also the succession of historical tradition of enjoyment. The integrity in Scenic Site refers to the physical and social conditions under which authenticity can be satisfactorily protected. The aim of this study is to reconstruct the traditional ways of enjoying historical and cultural Scenic Site with emphasis on the Yeongnam Region and make a critical examination of cultural property protection areas that have been designated. Then, this study aims to find the ways to utilize Scenic Site to secure the standards of authenticity and integrity. As a result it was discovered that cultural property protection areas are not designated well enough to satisfy the standards of authenticity and integrity. Considering the fact that cultural property protection areas are the minimal institutional systems to maintain the original value of Scenic Site, it is necessary to pay more careful attention to the ways of securing the authenticity and integrity in Scenic Site.

• Journal of Advanced Navigation Technology
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• v.15 no.4
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• pp.510-516
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• 2011

For using Global Navigation Satellite System(GNSS) in the civil aviation, it should satisfies the Required Navigation Performances(RNPs) which are defined by International Civil Aviation Organization(ICAO). RNP defines the required accuracy, integrity, availability, continuity of each flight procedure. In order to guarantee user's integrity, user's protection level has to be overestimated. On the other hand, for improving user's availability, user's protection level has to be estimated tightly. Therefore protection level should be estimated as tight as possible while it assuring the user's integrity. This paper describes the current integrity function of Korean WAD GNSS test bed, and predicts the availability performance of Korean WAD GNSS by simulation.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.5
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• pp.1159-1168
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• 2012

Control Flow Integrity(CFI) and Control Flow Locking(CFL) prevent unintended execution of software and provide integrity in control flow. Attackers, however, can still hijack program controls since CFI and CFL does not support fine-granularity, context-sensitive protection. In this paper, we propose a new CFI scheme, Source-code CFI(SCFI), to overcome the problems. SCFI provides context-sensitive locking for control flow. Thus, the proposed approach protects software against the attacks on the previous CFI and CFL schemes and improves safety.

• Journal of Positioning, Navigation, and Timing
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• v.10 no.4
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• pp.263-269
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• 2021

The carrier-based differential global navigation satellite system (CD-GNSS) has been garnering significant attention as a promising technology for unmanned vehicles for its high accuracy. The CD-GNSS systems to be used for safety-critical applications should provide a certain level of integrity. The integrity of these systems must be analyzed under various conditions, including fault-free and satellite fault conditions. The systems should be able to detect the faults that can cause large biases on the user position errors and quantify the integrity risk by computing the protection level (PL) to protect the user against the faults that are left undetected. Prior work has derived and investigated the PL for the fault-free condition. In this study, the integrity of the CD-GNSS system under the fault condition is analyzed. The position errors caused by the satellite's fault are compared with the fault-free PL (PL_H0) to verify whether the integrity requirement can be met without computing the PLs for the fault conditions. The simulations are conducted by assuming the ephemeris fault, and the position errors are evaluated by changing the size of the ephemeris faults that missed detection. It was confirmed that the existing fault monitors do not guarantee that the position error under the fault condition does not exceed the PL_H0. Further, the impact of the faults on the position errors is discussed.

• Journal of Positioning, Navigation, and Timing
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• v.11 no.4
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• pp.317-325
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• 2022

In this paper, we developed a single frequency-based RRAIM to monitor integrity of the UAM landing vertically in urban area with only low-cost single-frequency GPS receiver. Conventional dual-frequency RRAIM eliminates ionospheric delay through a combination of frequencies. In this study, ionospheric delay was directly modeled. Drift error of residual ionospheric delay is modeled using the previously studied result on ionospheric rates of change. To verify the performance of the proposed RRAIM algorithm, a simulation of vertical landing UAM in urban area was conducted. It was assumed that the protection level at the initial position was calculated through SBAS correction data. During vertical landing, integrity monitored by receiver alone without external correction data. In the 60 sec simulation, the protection level of the proposed RRAIM compared to the conventional RRAIM was calculated to be 140% due to the accumulated ionospheric delay error. Nevertheless, it was confirmed that the final vertical protection level meeting the requirements of LPV-200, which cannot be achieved with single frequency GPS receiver alone.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.4
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• pp.372-382
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• 2009

A GNSS software for processing the SBAS correction data is developed, and Japan MSAS correction data is analyzed. MSAS orbit correction data is analyzed and compared with WAAS data. MSAS ionosphere correction data is analyzed and the effect of the equatorial anomaly on the correction accuracy is discussed. Degradation due to receive delay of correction information and effect of the degradation on protection level analyzed using partial remove of MSAS correction information. Integrity and availability for precision approch using the MSAS system analyzed.

• Journal of Information Processing Systems
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• v.12 no.3
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• pp.538-547
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• 2016

Cloud computing is a new style of computing in which dynamically scalable and reconfigurable resources are provided as a service over the internet. The MapReduce framework is currently the most dominant programming model in cloud computing. It is necessary to protect the integrity of MapReduce data processing services. Malicious workers, who can be divided into collusive workers and non-collusive workers, try to generate bad results in order to attack the cloud computing. So, figuring out how to efficiently detect the malicious workers has been very important, as existing solutions are not effective enough in defeating malicious behavior. In this paper, we propose a security protection framework to detect the malicious workers and ensure computation integrity in the map phase of MapReduce. Our simulation results show that our proposed security protection framework can efficiently detect both collusive and non-collusive workers and guarantee high computation accuracy.