• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.9
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• pp.760-770
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• 2012

In order to provide precision approach service based on GBAS, air navigation service providers should validate the GBAS system performance against international standard requirements and receive approval. The GBAS manufacturer should define integrity threat, analyze the integrity monitors and evaluate performance of the implemented monitors to verify integrity performance which is critical to the aircraft safety. This paper describes a statistical test result to evaluate performance of the code carrier divergence monitors implemented in KARI Integrity Monitor System software. The paper introduces analysis and test procedure which is developed for the performance evaluation and describes the analysis, the test scenario generation and the test results. The results show that the implemented monitors can detect the expected minimum detectable errors with satisfying the probability of missed detection requirements.

• The Journal of the Korea Contents Association
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• v.8 no.8
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• pp.47-56
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• 2008

MC(Mission Computer) performs important function in avionics system which tactic data processing, image processing and managing navigation system etc. In general, the fault of SPOF(Single Point Of Failure) in unity system can lead to failure of whole system. It can cause a failure of a mission and also can threaten to the life of the pilot. So, in this paper, we design the HA(Hight-availability) system so that dealing with the failure. And we use HA software like Heartbeat, Fake, DRBD and Bonding to manage HA system. Also we analyze the performance of HA system using the FDT(Fault Detection Time) for fast fault detection and MTTR(Mean Time To Repair) for mission continuity.

• Journal of Digital Convergence
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• v.15 no.9
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• pp.223-230
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• 2017

In the current wireless Internet environment, using a mobile device to quickly access a web site is closely related to measuring the performance of a website. When accessing a website, the user has a long time to access the website and has no access to the website.In this case, the performance of the web site should be improved by measuring and analyzing the performance of the connection delay due to a problem of the web site.Among the performance measurement factors of Web sites, Web page loading time is a very important factor for a successful service business in the situation where most of e-commerce business is being developed as a web-based service.An open source tool was analyzed to analyze the performance of the e-commerce web page to present problems, software optimization methods and hardware optimization methods. Applying two optimization methods to suit the environment will enable stable and e-commerce websites.

• Journal of Industrial Convergence
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• v.18 no.1
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• pp.79-85
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• 2020

Recently, the RPAS(Remote Piloted Aircraft System), by remote control and autonomous navigation, has been increasing in interest and utilization in various industries and public organizations along with delivery drones, fire drones, ambulances, agricultural drones, and others. The problems of the stability of unmanned drones, which can be self-controlled, are also the biggest challenge to be solved along the development of the drone industry. drones should be able to fly in the specified path the autonomous flight control system sets, and perform automatically an accurate landing at the destination. This study proposes a technique to check arrival by landing point images and control landing at the correct point, compensating for errors in location data of the drone sensors and GPS. Receiving from the Google Map API and learning from the destination video, taking images of the landing point with a drone equipped with a NAVIO2 and Raspberry Pi, camera, sending them to the server, adjusting the location of the drone in line with threshold, Drones can automatically land at the landing point.

• KIPS Transactions on Software and Data Engineering
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• v.3 no.5
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• pp.179-186
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• 2014

Current networks such as social network, web page link, traffic network are big data which have the large numbers of nodes and edges. Many applications such as social network services and navigation systems use these networks. Since big networks are not fit into the memory, existing in-memory based analysis techniques cannot provide high performance. Frontier-Expansion-Merge (FEM) framework for graph search operations using three corresponding operators in the relational database (RDB) context. FEM exploits an index table that stores pre-computed partial paths for efficient shortest path discovery. However, the index table of FEM has low hit ratio because the indices are determined by distances of indices rather than the possibility of containing a shortest path. In this paper, we propose an method that construct index table using high degree nodes having high hit ratio for efficient shortest path discovery. We experimentally verify that our index technique can support shortest path discovery efficiently in real-world datasets.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.10
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• pp.906-915
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• 2016

In this study, a network monitoring system, including a secure 460-Network and a 460-Gateway, is designed and developed according with the requirements of the IEC (International Electro-Technical Commission) 61162-460 network standard for the safety and security of networks on board ships. At present, internal or external unauthorized access to or malicious attack on a ship's on board systems are possible threats to the safe operation of a ship's network. To secure the ship's network, a 460-Network was designed and implemented by using a 460-Switch, 460-Nodes, and a 460-Gateway that contains firewalls and a DMZ (Demilitarized Zone) with various application servers. In addition, a 460-firewall was used to block all traffic from unauthorized networks. 460-NMS (Network Monitoring System) is a network-monitoring software application that was developed by using an simple network management protocol (SNMP) SharpNet library with the .Net 4.5 framework and a backhand SQLite database management system, which is used to manage network information. 460-NMS receives network information from a 460-Switch by utilizing SNMP, SNMP Trap, and Syslog. 460-NMS monitors the 460-Network load, traffic flow, current network status, network failure, and unknown devices connected to the network. It notifies the network administrator via alarms, notifications, or warnings in case any network problem occurs. Once developed, 460-NMS was tested both in a laboratory environment and for a real ship network that had been installed by the manufacturer and was confirmed to comply with the IEC 61162-460 requirements. Network safety and security issues onboard ships could be solved by designing a secure 460-Network along with a 460-Gateway and by constantly monitoring the 460-Network according to the requirements of the IEC 61162-460 network standard.

• The Journal of Korean Association of Computer Education
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• v.5 no.1
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• pp.85-98
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• 2002

In this study, We are developed learner traits analysis and profile management software modules to develop learnable courseware fits to learner's individual traits in cyber learning system. We specified learner's personal information, performance information, preference information and portfolio information as learner's traits variables in this study, these four types of information are managed in learner profile management DB based on elaborate analysis to learner's traits. And we consists of curriculum sequencing module using high and low level sequencing technology, these are used in organizing learning contents sequencing with learning topic and specific learning task. The advice algorithm module developed based on adaptive navigational support and rule based technology. This Result of Research are able to be used for develop learnable courseware fits to learner's individual traits in cyber learning systems.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.36 no.4
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• pp.245-254
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• 2018

Impact of tropospheric correction techniques on accuracy of the GPS (Global Positioning System) derived ellipsoidal heights has been experimentally assessed in this paper. To this end, 247 baselines were constructed from a total of 88 CORS (Continuously Operating Reference Stations) in Korea. The GPS measurements for seven days, acquired from the so-called integrated GNSS (Global Navigation Satellite Systems) data center via internet connection, have been processed by two baseline processing software packages with an application of the empirical models, such as Hopfield, modified Hopfield and Saastamoinen, and the estimation techniques based on the DD (Double-Differenced) measurements and the PPP (Precise Point Positioning) technique; hence a total number of the baseline processed and tested was 8,645. Accuracy and precision of the estimated heights from the various correction schemes were analyzed about baseline lengths and height differences of the testing baselines. Details of these results are summarized with a view to hopefully providing an overall guideline of a suitable selection of the modeling scheme with respect to processing conditions, such as the baseline length and the height differences.

• Journal of Fashion Business
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• v.19 no.5
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• pp.63-76
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• 2015

The purpose of this study was to design a training program for utilization of 3D special makeup mask program. This study was conducted with a 3D computer graphics software program, for special makeup mask using a variety of creative educational models and case study with comparative analysis. The makeup program applied to the majors and liberal arts classes for program design. Inthis study, the selected major courses included ' stage make up ', make up application', and illustrations and color '. Students were required to take a class targeted to questionnaire completion and analysis. The research method included literature search, and Internet navigation, of experimental research. The research targeted select college students attending a 4-year university located in Dae-jeon, Korea. ETRI's "3D mask special makeup simulation program" was used in support. A survey of the study conducted from September 1, 2013, to August 30, 2014, showed a total of 94 additional statistical analyses. First, grade 3 44.6% was attained by 91.7% of the first year student majoring in liberal arts classes, Second, students' in the 3D special dress up mask program Interestingly, attained high recognition in its mastering, usability, and creativity. Furthermore, the major student satisfaction was higher for the '3D special makeup mask program. Third, students '3D special dress up was one of the biggest advantages of the program', the mask ' that models 3D ' faces. In addition, the student's delicate dress called for critical technology skills. It is thought to be suitable for practical training and improving the efficiency and performance if applied to universities and beauty schools, such as the regular high school curriculum through research.

• Journal of Ocean Engineering and Technology
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• v.32 no.5
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• pp.402-409
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• 2018

This paper describes the plan and procedure of a development test and evaluation that will be performed to verify the performance and technology of multi-mission unmanned surface vehicles (MMUSVs). In order to verify the design requirement of MMUSVs, we designed and manufactured the common platform of MMUSVs, which have an overall length of8.4 m, a displacement of 3,100 kg, and a speed of more than35 kts. The platform is equipped with several sub-systems, including radar and an EOTS/IRS. The EOTS/IRS, along with the search radar, is used for effective detection, identification, and targeting. The core technologies of MMUSV for DT&E will be investigated. The common platform design technologies, remote operating and control system technologies, autonomous navigation technologies, and unmanned operational technology of sensors and equipment will be studied for the development of the MMUSV's core technologies. The system will be able to make precise observations and track targets both manually and automatically during day and night conditions. Currently, the verification tests for each of the technologies and for the integrated system are in the pipeline for DT&E, which will be performed next year. Also, software reliability and life tests will be performed.