• Journal of Advanced Navigation Technology
• /
• v.24 no.2
• /
• pp.101-106
• /
• 2020

In order to smoothly control the speed of the induction motor, it is necessary to obtain the required rotor speed information. In order to obtain the speed information, it must be obtained using a sensor, but it can also be obtained using an appropriate algorithm without using a sensor. In order to obtain speed information, a system was designed using a model reference adaptive system (MARS). Indirect vector control, one of the speed control methods of induction motors, was calculated from the motor current and rotor parameter values. The method of obtaining the position information of the magnetic flux by combining the slip frequency with the rotor speed was used. It is possible to simply perform instantaneous current control in a wide speed range without actual magnetic flux information, and has the advantage that the structure of the controller is simple. Therefore, in this paper, the control system was constructed based on the indirect vector control method, and the speed control system of the induction motor was developed by estimating the required rotor speed information as an intelligent algorithm developed without using it as a sensor.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.20 no.12
• /
• pp.2355-2362
• /
• 2016

Seg fog removal is an important issue concerned by both computer vision and image processing. Sea fog or haze removal is widely used in lots of fields, such as automatic control system, CCTV, and image recognition. Color image dehazing techniques have been extensively studied, and expecially the dark channel prior(DCP) technique has been widely used. This paper propose a fast and efficient image prior - dark channel prior to remove seg-fog from a single digital image based on the GPU. We implement the basic parallel program and then optimize it to obtain performance acceleration with more than 250 times. While paralleling and the optimizing the algorithm, we improve some parts of the original serial program or basic parallel program according to the characteristics of several steps. The proposed GPU programming algorithm and implementation results may be used with advantages as pre-processing in many systems, such as safe navigation for ship, topographical survey, intelligent vehicles, etc.

• Convergence Security Journal
• /
• v.14 no.2
• /
• pp.35-41
• /
• 2014

With ubiquitous computing and network, the concern of government, business and academy for IT or ICT convergence has been increased. In this paper, through the analysis of keyword trend for ICT convergence services from 2000's mid, the efficient policy is proposed by estimating the understanding and concern of common people. In addition to, the concept and development step of convergence are analyzed, and the keyword analysis for the ICT convergence services defined in TTA is performed. The services are classified into smart home work transportation, Health ICT, RFID USN, M2M IoT, e-Navigation, intelligent robot, and the keywords for each service are analyzed. The analytic results indicate that the keyword trend varies in the time, and highly indexing keywords and new trend are defined. To provide the efficient ICT services, the new ICT convergence services needed for customer will be proposed with new IT technology development, IT standard, law management, and policy provisioining.

• Journal of Advanced Navigation Technology
• /
• v.18 no.1
• /
• pp.14-21
• /
• 2014

In this paper, we devise a new ontology-based context-aware system to recognize the smart car information, in which driver's intent is utilized by information of car, driver, environment as well as driving state, driver state. So proposed system can handle dynamically risk changes by adding real-time situational awareness information. We utilize the camera image recognition technology for context-aware intelligent vehicle driving information, and implement information acquisition scheme OBD-II protocol to acquire vehicle's information. Experiments confirm that the proposed advanced driver safety assist system outperforms the conventional system, which only utilizes the information of vehicle, driver, and environmental information, to support the service of a high-speed driving, lane-departure service and emergency braking situation awareness.

• Journal of Advanced Navigation Technology
• /
• v.10 no.4
• /
• pp.319-326
• /
• 2006

In this paper, a fuzzy inference control system is proposed for a turbojet engine with fuel flow control input only. The proposed control system provides a practical fuel flow control method to prevent surge or flame out during engine acceleration or deceleration. A fuzzy logic is designed to obtain the fast acceleration and deceleration of the engine under the condition that the operating point should stay between the surge line and flame out control line. With using both engine rotating speed error and surge margin as fuzzy input variables, the desired engine rotating speed can be achieved to rapidly follow the engine control line without engine stall. Computer simulation using the MATLAB is realized to prove the proposed control performance to the turbojet engine which is linear modelized using DYGABCD program package.

• Journal of Advanced Navigation Technology
• /
• v.16 no.1
• /
• pp.41-53
• /
• 2012

The technologies used by the malicious codes have been being advanced and complicated through a merge of the existing techniques, while the damages by the malicious codes are moving from individuals and industries to organizations and countries. In this situation, the security experts are corresponding with the static analysis and the dynamic analysis such as signature searching and reverse engineering, respectively. However, they have had a hard time to respond against the obfuscated intelligent new zero day malicious codes. Therefore, it is required to prepare a process for a preliminary investigation and consequent detailed investigation on the infection sequence and the hiding mechanism to neutralize the malicious code. In this paper, we studied the formalization of the process against the infection sequence and the file hiding techniques with an empirical application to the Rustock malicious code that is most notorious as a spammer. Using the result, it is expected to promptly respond to newly released malicious codes.

• Journal of Advanced Navigation Technology
• /
• v.13 no.6
• /
• pp.933-942
• /
• 2009

In this paper, the WAVE technology for IT based on Intelligent Transport System(ITS) which using by IEEE 802.11a PHY, IEEE 802.11p MAC(Medium Access Control) and IEEE P1609.3 was implemented. The WAVE system was designed that has maximum 0.5km communication range for RSU(Road Side Equipment) between vehicle, 12Mbps transfer speed when downlink at maximum 120km/h vehicle speed. To verify suitableness of the WAVE system for ITS, we measured several parameters on the real road: communication range when low and high speed, link establishment time, data transfer speed, PER (Percent Error Rate), and latency. From the experiment results, we demonstrated that WAVE is a suitable technology for IT based on ITS.

• Journal of Advanced Navigation Technology
• /
• v.14 no.2
• /
• pp.151-160
• /
• 2010

For the realization of future intelligent transportation systems, fine-grained lane-by-lane traffic monitoring and control functionalities are among the most important technology barriers to overcome. To satisfy the accuracy requirement for traffic monitoring, a GNSS receiver network is designed. The designed receiver network consists of three different types of entities; reference server, broadcaster, and client. For deployment flexibility, all the entities utilize the international message standard RTCM SC-104 version 3.0. For fine-grained traffic monitoring, the client is designed to utilize position-domain carrier-smoothed-code filters to provide accurate vehicle coordinates in spite of frequent addages and outages of visible satellites. An experiment result is presented to evaluate the positioning accuracy of the proposed method.

• Journal of Advanced Navigation Technology
• /
• v.23 no.6
• /
• pp.589-596
• /
• 2019

With the proliferation of intelligent transportation system (ITS) with dedicated short-range communication (DSRC) deployment, there are various applications requiring different throughput and reliability performance. To meet the enhanced throughput requirements in newly generated applications, IEEE 802.11bd is proposed to standardize for support of enhanced throughput and latency, preserving the fairness with previously deployed WLAN V2X devices. One of the main features of IEEE 802.11 bd is 20 MHz transmission to support the high data rate. In this paper, the primary channel selection method is proposed to guarantee the fairness with frame transmissions with 10 MHz bandwith including communications in WLAN V2X devices deployed with IEEE 802.11p. Simulation shows that the proposed channel access method for 20 MHz transmission with primary selection preserves the fairness without the change of channel access method in wide-band transmission.

• Journal of Navigation and Port Research
• /
• v.29 no.1 s.97
• /
• pp.59-64
• /
• 2005

MDMG(Multiple Decision-Making Group) problems comprise those of UDMG(Unit Decision-Making Group) which contradict each other. For the evaluation problem of port competitiveness, it has the complicated evaluation characteristics of multi-strata-complex and multi-attributes. Especially, it becomes typical MDMG problems in the evaluation which a great number of decision makers such as shipping companies, freight forwarders, logistics companies and researchers participate in This evaluation of complex problems needs the compensated process of weight which rationally unites heterogeneous preferences of each of groups. In this respect, the purpose of this study is to remove the uncertainty of the UDMG using the theory of DS (Dempster-Shafer) and present the integrated weight through the level process.