• Journal of the Earthquake Engineering Society of Korea
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• v.20 no.1
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• pp.1-8
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• 2016

Permanent deformation plays a key role in performance based earthquake resistant design. In order to estimate permanent deformation after earthquake, it is essential to secure reliable response history analysis(RHA) as well as earthquake scenario. This study focuses on permanent deformation of an inverted T-type wall under earthquake. The study is composed of two separate parts. The first one is on the verification of RHA and the second one is on an effect of input earthquake motion. The former is discussed in this paper and the latter in the companion paper. The verification is conducted via geotechnical dynamic centrifuge test in prototype scale. Response of wall stem, ground motions behind the wall obtained from RHA matched pretty well with physical test performed under centrifugal acceleration of 50g. The rigorously verified RHA is used for parametric study to investigate an effect of input earthquake motion selection in the companion paper.

• Nuclear Engineering and Technology
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• v.56 no.7
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• pp.2704-2710
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• 2024

Nuclear archaeology research provides scientific methods to reconstruct the operating histories of fissile material production facilities to account for past fissile material production. While it has typically focused on analyzing material in permanent reactor structures, spent fuel or high-level waste also hold information about the reactor operation. In this computational study, we explore a Bayesian inference framework for reconstructing the operational history from measurements of isotope ratios from a sample of nuclear waste. We investigate two different inference models. The first model discriminates between three potential reactors of origin (Magnox, PWR, and PHWR) while simultaneously reconstructing the fuel burnup, time since irradiation, initial enrichment, and average power density. The second model reconstructs the fuel burnup and time since irradiation of two batches of waste in a mixed sample. Each of the models is applied to a set of simulated test data, and the performance is evaluated by comparing the highest posterior density regions to the corresponding parameter values of the test dataset. Both models perform well on the simulated test cases, which highlights the potential of the Bayesian inference framework and opens up avenues for further investigation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.3C
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• pp.257-267
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• 2009

This paper presents a training method for neural networks and the employment of MSE (mean scare error) values as the basis of a decision regarding the identity claim of a speaker in a recurrent neural networks based speaker verification system. Recurrent neural networks (RNNs) are employed to capture temporally dynamic characteristics of speech signal. In the process of supervised learning for RNNs, target outputs are automatically generated and the generated target outputs are made to represent the temporal variation of input speech sounds. To increase the capability of discriminating between the true speaker and an impostor, a discriminative training method for RNNs is presented. This paper shows the use and the effectiveness of the MSE value, which is obtained from the Euclidean distance between the target outputs and the outputs of networks for test speech sounds of a speaker, as the basis of speaker verification. In terms of equal error rates, results of experiments, which have been performed using the Korean speech database, show that the proposed speaker verification system exhibits better performance than a conventional hidden Markov model based speaker verification system.

• Aerospace Engineering and Technology
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• v.5 no.2
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• pp.108-113
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• 2006

This paper includes the test results of KOMPSAT-2 payload downlink system which were measured for the purpose of performance verification. The antenna beam patterns which indicates the status of the interface & antenna itself, were measured as well as the antenna VSWR. The checkout of the transponder & its spectrum was followed and this made sure that there was no spurious output distinguished. Finally a test for BER verification was conducted between satellite and receiving system for their compatibility through the antenna-to-antenna connection using an antenna hat. Verification tests for an RF system should be performed after relocation, integration and test for environments in order to make sure that no degradation happens.

• JSTS:Journal of Semiconductor Technology and Science
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• v.2 no.2
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• pp.132-140
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• 2002

This paper presents an ARM-based SOC bus transaction verification IP and the usage experiences in SOC designs. The verification IP is an AMBA AHB protocol checker, which captures legal AHB transactions in FSM-style signal sequence checking routines. This checker can be considered as a reusable verification IP since it does not change unless the bus protocol changes. Our AHB protocol checker is designed to be scalable to any number of AHB masters and reusable for various AMBA-based SOC designs. The keys to the scalability and the reusability are Object-Oriented Programming (OOP), virtual port, and bind operation. This paper describes how OOP, virtual port, and bind features are used to implement AHB protocol checker. Using the AHB protocol checker, an AHB simulation monitor is constructed. The monitor checks the legal bus arbitration and detects the first cycle of an AHB transaction. Then it calls AHB protocol checker to check the expected AHB signal sequences. We integrate the AHB bus monitor into Verilog simulation environment to replace time-consuming visual waveform inspection, and it allows us to find design bugs quickly. This paper also discusses AMBA AHB bus transaction coverage metrics and AHB transaction coverage analysis. Test programs for five AHB masters of an SOC, four channel DMAs and a host interface unit are executed and transaction coverage for DMA verification is collected during simulation. These coverage results can be used to determine the weak point of test programs in terms of the number of bus transactions occurred and guide to improve the quality of the test programs. Also, the coverage results can be used to obtain bus utilization statistics since the bus cycles occupied by each AHB master can be obtained.

• Nuclear Engineering and Technology
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• v.49 no.5
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• pp.989-995
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• 2017

Distributed Control System (DCS) communication networks, which use Fast Ethernet with redundant networks for the transmission of information, have been installed in digitalized nuclear power plants. Normally, failover tests are performed to verify the reliability of redundant networks during design and manufacturing phases; however, systematic integrity tests of DCS networks cannot be fully performed during these phases because all relevant equipment is not installed completely during these two phases. In additions, practical verification tests are insufficient, and there is a need to test the actual failover function of DCS redundant networks in the target environment. The purpose of this study is to verify that the failover functions works correctly in certain abnormal conditions during installation and commissioning phase and identify the influence of network failover on the entire DCS. To quantify the effects of network failover in the DCS, the packets (Protocol Data Units) must be collected and resource usage of the system has to be monitored and analyzed. This study introduces the use of a new methodology for verification of DCS network failover during the installation and commissioning phases. This study is expected to provide insight into verification methodology and the failover effects from DCS redundant networks. It also provides test results of network performance from DCS network failover in digitalized domestic nuclear power plants (NPPs).

• The Journal of the Acoustical Society of Korea
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• v.22 no.1
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• pp.42-47
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• 2003

This paper proposes the method to generate new test data using the sample shift of the start frame for SPRT(sequential probability ratio test) in speaker verification. The SPRT method is a effective algorithm that can reduce the test computational complexity. However, in making the decision procedure, SPRT can be executed on the assumption that the input samples are usually to be i.i.d. (Independent and Identically Distributed) samples from a probability density function (pdf), also it's not suitable method to apply for the short utterance. The proposed method can achieve SPRT regardless of the utterance length of the test data because it is method to generate the new test data through the sample shift of start frame. Also, the correlation property of data to be considered in the SPRT method can be effectively removed by employing the principal component analysis. Experimental results show that the proposed method increased the computational complexity of data for sample shift a little, but it has a good performance result more than a conventional method above the average 0.7% in EER (equal error rate).

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.5
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• pp.446-453
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• 2012

As part of the integration phases in developing a UAV, a System Integration Laboratory (SIL) has been developed to provide integrated test capability for the verification of avionics system requirements. The SIL has realized primary functions that are common in manned aircraft SIL's, and specialized laying stress on test data visualization and test automation under the closed-loop structure of the ground control simulation, aircraft simulation and flight simulation components. Those design results have led to easy and sure verification of lots of complex requirements of the UAV avionics system. The functions and performances of the SIL have been proved in four gradational test steps and checked to operate successfully in aircraft System Integration Test Environment for the integration of UAV ground station and aircraft.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.11a
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• pp.155-158
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• 2007

As a secondary stage of the liquid rocket engine development test, turbopump-gas generator powerpack tests are being performed. The schematics of the test hardware and the test facility for the TP+GG coupled test are presented. The results of a preliminary test results for the verification of the propellant supply system of the test facility are also presented. Based on the preliminary tests results, the verification of the propellants supply systems of the facility system was performed.

• Journal of Positioning, Navigation, and Timing
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• v.13 no.3
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• pp.257-268
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• 2024

The Korea Augmentation Satellite System (KASS) satellite was successfully launched and service is being started. By receiving messages transmitted from the KASS satellite, users can employ the messages to improve positioning accuracy or to verify the integrity of Global Positioning System (GPS). In this paper, we propose a test method for a beam-formed GPS receiver developed to improve the survivability of KASS augmented messages that can enhance positioning accuracy even in an environment with jamming or interfering signals. Through the test method proposed in this paper, quantitative verification is performed for a beam-formed GPS receiver aimed at maintaining the augmented navigation solution to which KASS augmented messages are applied by tracking the KASS signal as much as possible under conditions where the jamming signal strength is gradually increasing. In addition, the proposed test method includes three conditions; first, a static lab test method for repeated verification of functions under the same conditions; second, a static outdoor test method for performance verification in an operating environment of a platform equipped with the beam-formed GPS receiver; and finally, a dynamic lab test method for performance verification of a moving platform equipped with the beam-formed GPS receiver toward a jammer. In this paper, we propose a method for simulating the jamming signal incident direction through the phase delay of an RF cable designed to prevent unintentional jamming signal emission in both lab and outdoor tests, and a method of applying test software for injecting a jamming signal to compare the survivability performance consistently according to the presence or absence of beamforming signal processing. Through the proposed test method, it was verified that the augmented navigation solution could be output for a longer time period when the beamforming signal processing was applied to the KASS satellite signal in the beam-formed GPS receiver.