• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.10a
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• pp.765-768
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• 2001

A universal shipborne automatic identification system(AIS) uses self-organised time division multiple access(SOTDMA). The performance evaluation system of the SOTDMA algorithm for AIS is needed to implement it efficiently. This paper shows the method of designing it. Real ships access the VHF maritime mobile band but in this performance system, several ship objects access the shared memory. Real ships are designed as the object and the wireless communication channel is designed as the shared memory. This system shows several stations are assigned the transmission slot by the SOTDMA algorithm

• Proceedings of KOSOMES biannual meeting
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• 2008.05a
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• pp.173-176
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• 2008

It is very important to protect life, property at sea and marine environments from any pollution AIS, which was been carried out July 1st, 2002 by SOLAS ch. 5, is an communication system to enhance navigational safety by transmitting and receiving vessel information automatically. In this paper, we investigated the positive factors expected by introducing AIS. For this, ship's collision accidents were analyzed. Finally, we suggest methods to solve several problems related to operation in AIS.

• Journal of Korean Library and Information Science Society
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• v.12
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• pp.61-96
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• 1985

The human subject analysis of a document has some critical problems. The method results in the inconsistency in analysis process and the contradiction of two objects of the subject analysis (one is the identification of the content for the retrieval of specific items and the other is to identify the content for the grouping of related materials). Since the subject analysis by mechanized has been recognized to be the possible way to aggregate the problems of manual analysis, various a n.0, pproaches of automatic indexing have been studied and experimented. This study is to examine the automatic indexing as one of the promising subject analysis techniques by statistical, syntactical and semantic a n.0, pproaches. In conclusion, the reasonable a n.0, pplication time of the automatic indexing should be made a decision based on the through investigation on the cost verse effectiveness, and automatic indexing system should be developed in the close relationship with the on-line search which is a good retrieval system for information explosion society. From now on, since the machine-readable document-text will be envisaged to be more and more available due to the rapid development of computer technology, the more substantial research on the automatic indexing will be also possible, which can bring about the increasing of practical automatic indexing systems.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.10
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• pp.862-870
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• 2016

AIS and V-PASS, which are used for safe navigation and automatic vessel arrival and departure, are mandatory standard equipment installed on all ships. If an aircraft is equipped with a ship identification system using AIS and V-PASS, and then ship identification information is received by a vessel such as a large fishery inspection boat or a patrol ship or a ground control system, we can quickly perform maritime surveillance and disaster response. This paper describes the development of a ship identification and display system using a ship identification device for aircraft. Flight test results and a future application plan are also included.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2005.10a
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• pp.93-97
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• 2005

Recently, as a method for identifying the vessels, the technology of automatic identification system, radio frequency identification and maritime mobile has been researched and developed rapidly. In this paper, the analysis of three identification systems on coastal vessels carried out by using ten itemized check list, and the best solution would be proposed as a method for identifying small boats in coastal waters.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.2 no.6
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• pp.299-311
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• 2008

The Radio Frequency IDentification (RFID) system is a contactless automatic identification system, which comprises readers and tags. In RFID systems, a reader collision occurs when there is interference in communication between one reader and the tags, due to the signals from other readers. The reader collision problem is considered as the fundamental problem affecting high density RFID reader installations. In this paper, we analyze the existing reader anti-collision algorithms. We also propose a pulse protocol-based reader anti-collision algorithm using slot occupied probability (SOP). The implementation of this improvement is simple, yet it effectively mitigates most reader collisions in dense reader mode, as shown in our simulation. That is, the proposed algorithm reduces the identification time, and increasesthe system throughput and system efficiency compared with the conventional reader anti-collision algorithms.

• Journal of the Korean Society for Railway
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• v.8 no.6 s.31
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• pp.533-538
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• 2005

In this paper we identity the hazard using HAZOP study for ATSRX which is a subsystem of the ATP system, and we study a safety management method for the mitigation of the risk to the acceptable level. ATSRX is a device that make a train which has a ATP system operate in ATS line. For this ATSRX send a induction signal with ATS system to vehicle controller. Thus ATSRX can be said a safety equipment that makes a train operate safely. In order to identify the hazard for the internal faults in ATSRX system, we employ HAZOP study method which is recommended as hazard identification in IEC 62278, RAMS requirements in railway signal, and also it provide the detail activity in IEC 61882. Thus, in this paper we perform HAZOP study based on ATSRX related standards and using the assessment of the identified hazard we study a method to guarantee the system safety through the change of the design to mitigate the risk to the acceptable level.

• Journal of the Korean Institute of Intelligent Systems
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• v.13 no.5
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• pp.545-551
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• 2003

Henry System which is a traditional fingerprint classification model is difficult to apply to a modem Automatic Fingerprint Identification System (AFIS). To tackle this problem, this study is to apply algorithm for an An Ensemble Fingerprint Classroom System using changes of gradient of ridge in order to improve precise joining speed of a large volume of database. The existing classification system, Henry System, is useful in a captured fingerprint image of core point and delta point using paper and ink. However, the Henry System is unapplicable in modem Automatic Fingerprint Identification System (AFIS) because of problems such as size of input sensor and way of input. This study is to suggest an Ensemble Fingerprint Classroom System which can classify 5 basic patterns of Henry System in uncaptured delta image using changes of gradient of ridge. The proposed fingerprint classification technique will make an improvement of precise joining speed by reducing data volume.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.4
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• pp.410-418
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• 1999

This paper describes the use of residual and parameter identification methods for fault detection in an air handling unit. Faults can be detected by comparing expected condition with the measured faulty data using residuals. Faults can also be detected by examining unmeasurable parameter changes in a model of a controlled system using a system identification technique. In this study, AutoRegressive Moving Average with seXtrnal input(ARMAX) and AutoRegressive with eXternal input(ARX) models with both single-input/single-input and multi-input/single-input structures are examined. Model parameters are determined using the Kalman filter recursive identification method. Regression equations are calculated from normal experimental data and are used to compute expected operating variables. These approaches are tested using experimental data from a laboratory's variable-air-volume air-handling-unit.

• Journal of Sensor Science and Technology
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• v.30 no.4
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• pp.196-203
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• 2021

In this study, an optical identification system was developed, wherein visible light is used to transmit the interrogating signal, and infrared is used to send the response signal. In the reader, visible light from a light emitting diode (LED) array was modulated via modified pulse width modulation for flicker-free illumination and dimming control. Moreover, the duty factor of the dimming control time was employed to control the illumination from the LED. In the transponder, the spike signal in the output of the high-pass filter was utilized to recover the interrogating signal while preventing interference from the 120-Hz noise from adjacent lighting lamps. The illumination was controlled in 26-86% range of the constant wave LED illumination by changing the duty factor from 20% to 90%. This configuration is advantageous for the construction of optical identification systems for automatic security check and car fare calculation at toll gates or parking facilities.