• Journal of Information Technology Services
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• v.8 no.2
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• pp.147-156
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• 2009

As the result of the rapid development of IT technology, an on-line diagnostic system using the field bus communication network coupled with a smart sensor module will be widely used at the nuclear power plant in the near future. The smart sensor system is very useful for the prompt understanding of abnormal state of the key equipments installed in the nuclear power plant. In this paper, it is assumed that a smart sensor system based on the fieldbus communication network for the surveillance and diagnostics of safety-critical equipments will be installed in the harsh-environment of the nuclear power plant. It means that the key components of fieldbus communication system including microprocessor, FPGA, and ASIC devices, are to be installed in the RPV (reactor pressure vessel) and the RCS (reactor coolant system) area, which is the area of a high dose-rate gamma irradiation fields. Gamma radiation constraints for the DBA (design basis accident) qualification of the RTD sensor installed in the harsh environment of nuclear power plant, are typically on the order of 4 kGy/h. In order to use a field bus communication network as an ad-hoc diagnostics sensor network in the vicinity of the RCS pump area of the nuclear power plant, the robust survivability of IT-based micro-electronic components in such intense gamma-radiation fields therefore should be verified. An intelligent CCD camera system, which are composed of advanced micro-electronics devices based on IT technology, have been gamma irradiated at the dose rate of about 4.2kGy/h during an hour UP to a total dose of 4kGy. The degradation performance of the gamma irradiated CCD camera system is explained.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.11
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• pp.1662-1668
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• 2005

This review has been done to examine sex-linked dwarf gene in broiler production in hot-humid climates. Introduction of sex-linked dwarf gene especially in hot harsh tropical environments brings a great advantage for broiler production. The heavy broiler parent suffers due to the stress of these adverse climates. Sex-linked dwarf genes reduce body weight, egg weight, but are superior for adaptability under harsh tropical environments, with a lower requirement for housing and feed, better survivability and reproductive fitness giving fewer defective eggs, more hatching eggs, better fertility, hatchability, feed conversion efficiency and resistance to disease. Overall the cost of chick production from dwarf hens is lower than from their normal siblings. Market weights of broilers from sexlinked dwarf dams is almost similar to those of broilers from normal dams with normal sires. But the net benefit of broiler production from sex-linked dwarf dams is found to be greater than that of broilers from normal dams. This will be the most important to the rural communities in Bangladesh and in other countries where the similar environment and socio-economic conditions exist. Therefore, sexlinked dwarf hens might be used in broiler breeding plan as well as broiler production in the tropics.

• Journal of Surface Science and Engineering
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• v.44 no.3
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• pp.105-116
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• 2011

Ships and offshore structures are exposed to harsh marine environments, and maintenance and repair are becoming increasingly important to the industry and the economy. The major corrosion phenomenons of metals and alloys in marine environment are pitting corrosion, stress corrosion cracking, crevice corrosion, fatigue corrosion, cavitation-erosion and etc. due to the effect of chloride ions and is quite serious. Methods of protection against corrosion can generally be divided into two groups: anodic protection and cathodic protection. Anodic protection is limited to the passivity characteristics of a material in its environment, while cathodic protection can apply methods such as sacrificial anode cathodic protection and impressed current cathodic protection. Sacrificial anode methods using Al and Zn alloys are widely used for marine structures and vessels intended for use in seawater. Impressed current cathodic protection methods are also widely used in marine environments, but tend to generate problems related to hydrogen embrittlement caused by hydrogen gas generation. Therefore, it is important to the proper maintenance and operation of the various corrosion protection systems for ship in the harsh marine environment.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.12 no.3
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• pp.250-255
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• 2012

Face recognition has wide applications in security and surveillance systems as well as in robot vision and machine interfaces. Conventional challenges in face recognition include pose, illumination, and expression, and face recognition at a distance involves additional challenges because long-distance images are often degraded due to poor focusing and motion blurring. This study investigates the effectiveness of applying photon-counting linear discriminant analysis (Pc-LDA) to face recognition in harsh environments. A related technique, Fisher linear discriminant analysis, has been found to be optimal, but it often suffers from the singularity problem because the number of available training images is generally much smaller than the number of pixels. Pc-LDA, on the other hand, realizes the Fisher criterion in high-dimensional space without any dimensionality reduction. Therefore, it provides more invariant solutions to image recognition under distortion and degradation. Two decision rules are employed: one is based on Euclidean distance; the other, on normalized correlation. In the experiments, the asymptotic equivalence of the photon-counting method to the Fisher method is verified with simulated data. Degraded facial images are employed to demonstrate the robustness of the photon-counting classifier in harsh environments. Four types of blurring point spread functions are applied to the test images in order to simulate long-distance acquisition. The results are compared with those of conventional Eigen face and Fisher face methods. The results indicate that Pc-LDA is better than conventional facial recognition techniques.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.1
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• pp.87-107
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• 2015

Considering the localization estimation issue in mixed line-of-sight (LOS)/non-LOS(NLOS) environments based on received signal strength (RSS) measurements in wireless sensor networks, a grid-based correlation method based on the relationship between distance and RSS is proposed in this paper. The Maximum-Likelihood (ML) estimator is appended to further improve the localization accuracy. Furthermore, in order to reduce computation load and enhance performance, an improved recursively version with NLOS mitigation is also proposed. The most advantages of the proposed localization algorithm is that, it does not need any prior knowledge of the propagation model parameters and therefore does not need any offline calibration effort to calibrate the model parameters in harsh environments, which makes it more convenient for rapid implementation in practical applications. The simulation and experimental results evidence that the proposed localization algorithm exhibits good localization performance and flexibilities for different devices.

• Journal of Positioning, Navigation, and Timing
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• v.9 no.4
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• pp.387-395
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• 2020

Accuracy of an integrated Global Positioning System (GPS) / Inertial Navigation System (INS) relies heavily on the visibility of GPS satellites. Especially, its accuracy is dramatically degraded in urban canyon due to signal obstructions due to large structures. In this paper, we propose a new integrated positioning system that effectively combines INS, GPS, ultrasonic sensor, and barometer in GPS-denied environments. In the proposed system, the ultrasonic sensor provides velocity information along the forward direction of moving vehicle. The barometer output provides height information compensated for the pressure variation due to fast vehicle movements. To evaluate the performance of the proposed system, an experiment was carried out by mounting the proposed system on a test car. By the experiment result, it was confirmed that the proposed system bears good potential to maintain positioning accuracy in harsh urban environments.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.332-336
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• 1991

Network management is responsible for gathering information on the usage of the network media by the network devices, ensuring the correct operation of the network, and providing reports. MAP network management must provide the high reliability of the media and signaling method, even in very harsh environments, providing a very low bit error rate and minimum number of retransmission. In this paper, we analysed the framework of OSI management and MAP network management and discussed the implementation method of fault management and remote management mechanism in the Mini-MAP controller developed for IBM-PC.

• International Journal of Oral Biology
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• v.43 no.4
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• pp.171-175
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• 2018

Quorum sensing (QS) is a cell density-dependent communication mechanism between bacteria through small signaling molecules. When the number of QS signaling molecules reaches a threshold, they are transported back into the cells or recognized by membrane-bound receptors, triggering gene expression which affects various phenotypes including bioluminescence, virulence, adhesion, and biofilm formation. These phenotypes are beneficial for bacterial survival in harsh environments. This review summarizes the application of QS inhibitors for control of biofilm formation and virulence expression of periodontal pathogens.

• International Journal of Aeronautical and Space Sciences
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• v.18 no.3
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• pp.555-564
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• 2017

In this paper, a new technique for attitude and heading reference system (AHRS) using low-cost MEMS sensors of the gyroscope, accelerometer, and magnetometer is addressed particularly in vibration environments. The motion of MEMS sensors interact with the scale factor and cross-coupling errors to produce random errors by the harsh environment. A new adaptive attitude estimation algorithm based on the Kalman filter is developed to overcome these undesirable side effects by analyzing windowed measurement error covariance. The key idea is that performance degradation of accelerometers, for example, due to linear vibrations can be reduced by the proposed measurement error covariance analysis. The computed error covariance is utilized to the measurement covariance of Kalman filters adaptively. Finally, the proposed approach is verified by using numerical simulations and experiments in an acceleration phase and/or vibrating environments.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.20 no.1
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• pp.7-15
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• 2024

Environmental qualification is required for safety related electrical equipment under harsh environments located in nuclear power plants according to 10 CFR 50.49 and RG 1.89. As analog technology has recently been replaced by digital technology, NRC established RG 1.209 as a regulatory guideline for environmental qualification of safety related computer-based I&C system located in mild environments, requiring evaluation for electromagnetic compatibility, smoke exposure and type test for actual service conditions such as temperature and humidity. In this paper, the trend of environmental qualification for digital equipment is analyzed by comparing the environmental qualification requirements between digital and analog equipment.