• Architectural research
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• v.18 no.4
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• pp.179-184
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• 2016

The structure must be periodically checked and measures must be taken to prevent deterioration in building construction. From this point of view, a nondestructive test is essential to estimate whether the construction of buildings is proper, and whether the dimension of depositing concrete is consistent and without damage. This study estimated the thickness of the concrete component of construction framework using the ultrasonic velocity method and the impact echo method, in order to investigate reliability of the estimation of the thickness of normal strength concrete and high strength concrete, leading to the following conclusions. In the estimation of the thickness of the concrete structures, specimens of normal strength of 24MPa and specimens of high strength of 40MPa demonstrated an average error rate of 5.1% and 2.2%, respectively. The impact-echo method, one of the non-destructive tests, is verified as an efficient diagnostic technique. With this information, we will determine specific standards for the maintenance of structures, and the re-creation of lost building blueprints.

• Journal of Environmental Impact Assessment
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• v.20 no.1
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• pp.25-36
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• 2011

In this study, the accurate water quality analysis in rivers, including the non-point source is performed. First of all, watershed model, SWAT(Soil and Water Assessment Tool) was applied to analyze the impact of the non-point source in study area. And then, water quality analysis integrating the point source and the non-point source is implemented using QUALKO model. For more exact simulation, it should be the calibration and verification of variables and parameters which are needed for simulation. In addition, the importance of considering the non-point source was confirmed in river water quality simulation. BOD, TN, TP were analysed, and the results shows that BOD, TN and TP concentration was increased to 16.8%, 8.2% and 25.8% respectively. The more accurate estimate will be carried if use of reliable measurements and watershed simulation be done in models linking process. The suggested technique will improve the accuracy of the water quality analysis. The methodologies presented in this study will contribute to basin-wide water quantity and quality management.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.623-629
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• 2002

The spectrum of impulse response signal from an impulse hammer testing is widely used to obtain frequency response function(FRF) of the structure. However the FRFs obtained from impact hammer testing have not only leakage errors but also finite record length errors when the record length for the signal processing is not sufficiently long. The errors cannot be removed with the conventional signal analyzer which treats the signals as if they are always steady and periodic. Since the response signals generated by the impact hammer are transient and have damping, they are undoubtedly non-periodic. It is inevitable that the signals be acquired for limited recording time, which causes the finite record length error and the leakage error. In this paper, the errors in the frequency response function of multi degree of freedom system are formulated theoretically. And the method to remove these errors is also suggested. This method is based on the optimization technique. A numerical example of 3-dof model shows the validity of the proposed method.

• Journal of Biosystems Engineering
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• v.33 no.4
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• pp.239-247
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• 2008

Firmness is very important factor to evaluate the freshness and ripeness among the various factors, in concerning about the melon quality. This study was carried out to develop the technique using impact signal to measure the melon firmness nondestructively. Results of analyzing impulse signals of melons having different firmness levels showed that the firmness of melon affected various impulse responses including amplitude, transmitted time, maximum peak frequency, firmness index 1 ($f^2m$), and firmness index 2 ($f^2m^{2/3}$). Impulse signal amplitude was the best indicator to predict the firmness of melon because of a strong corelation ($R^2\;=\;0.9071$). Firmness index 1, firmness index 2, maximum peak frequency, and normalized transmitted time were also possible indicators with acceptable correlation values.

• Journal of the Korean Operations Research and Management Science Society
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• v.42 no.2
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• pp.35-48
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• 2017

As the technology convergence paradigm emerges, the need for "CIA techniques" to analyze the mutual effects of technology is increasing. However, since the CIA input parameter estimation is difficult, the present study suggests a "CIA input parameter setting model" to alleviate the difficulty of CIA input parameter estimation. This paper is focused on the difference of measurement difficulty by each scale which expert's estimation behavior was defined as measurement activity quantifying the judgment of future technology. Therefore, this model is designed to estimate the input variable as a sequence or isometric scale that is relatively easy to measure, and then converts it into a probability value. The input parameter setting model of the CIA technique consists of three sub-models : 'probability value derivation model', 'influence estimation model', and 'impact value calculation model', in order to develop a series of models the Thurstone V model, Regression Analysis, etc has been used.

• Journal of the Society of Naval Architects of Korea
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• v.30 no.4
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• pp.61-73
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• 1993

In the present study, sloshing problem is analyzed by the application of Finite Difference Method. SOLA-SURF scheme is applied to the analysis of fluid motion considering free surface. Especially, the concept of impact buffer zone is introduced for the prediction of more realistic impact pressure on tank. Numerical computation is carried out for the typical three models, and the computed results show good agreement with experimental data. The computation is also performed for 300,000 tons VLCC as a real-ship application. From the present study, it is proved that this numerical technique is quite practical to the prediction of sloshing impact pressure.

• Journal of Environmental Impact Assessment
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• v.18 no.6
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• pp.387-392
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• 2009

As Our society's environmental awareness and concern the significant increases, the importance of the legal system for environmental conservation such as the Prior Environmental Review System, Environmental Impact Assessment is growing increasingly. but, still critical issues are present such as reliability. Though there could be various causes such as the system or procedures etc. Above all, basically the environmental data problem is the critical cause. Therefore, this study was trying to improve the environmental data accuracy using the high-resolution color aerial photography, LiDAR data and Object Oriented Classification method. And in this study, classification based on coverage percentage of a particular species was attempted through the multi-resolution segmentation and multi-level classification method. The classification result was verified by comparison with 11 points local survey data. All 11 points were classified correctly. And even though the exact coverage percentage of the particular species did not be measured, It was confirmed that the species was occupied similar portion. It is important that the environmental data which can be used for the conservation value assessment could be acquired.

• Journal of Environmental Impact Assessment
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• v.18 no.1
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• pp.11-19
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• 2009

We conducted human risk assessment due to inhalation exposure to heavy metals emitted from incinerator. The process of health impact assessment(HIA) on incinerator is as follows: The first step is to presume and calculate the amount of heavy metals emitted using emission factor. The second step is to conduct an exposure assessment using the K-SCREEN model which is used for predicting the concentration in a conservative method. The last step is to carry out a risk assessment on carcinogenic and non-carcinogenic substances. This study revealed that rank of carcinogenic human risk was $Cr^{+6}$ > As > Ni > Cd, and values of human risk assessment on carcinogenic and non-carcinogenic substances is lower than the US criteria for risk assessment except $Cr^{+6}$. It is expected that the technique of HIA, especially human risk assessment on heavy metals, would be applied to the incinerator construction project. In addition, more systematic studies are needed to overcome some weak points and limits found in this study.

• Journal of Environmental Impact Assessment
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• v.20 no.4
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• pp.565-574
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• 2011

This paper aims to design a policy-assessment tool liking the Environmental Impact Assessment(EIA) and the Cost Benefit Analysis (CBA). As a step towards the incorporation of environmental and economic considerations, the approach used herein takes the form of integrating quantitative information on environmental benefits and costs associated with implementing the project into the existing framework of the EIA. Our case study is an project appraisal of a solar energy plant. It is confirmed that the technique is operational, however, there are certain limitations for a complete assessment. The difficulty mainly originated from the omission of important information from each step of the valuation process. Alternatively stated, some environmental services are not identified, nor quantified, and nor monetized in the process. More case studies are warranted in the future along with elaboration in methodology of techniques. In addition, the construction of a database on environmental values will be required to accumulate reliable and systematized data. These are the necessary conditions to improving quality in application of techniques as well as providing comprehensive and balanced information to decision makers.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.10
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• pp.377-389
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• 2020

This research focuses on identifying and measuring key personality factors affecting the job performance of salesperson working in the machinery industry in Vietnam. A total number of 218 salesperson working in machinery industry were surveyed. After evaluating Cronbach's Alpha and using the regression analysis technique, the results show the impact level of personality trait factors affecting the job performance of salesperson working in machinery industry. Ordered from the highest to the lowest effects on job performance, these factors are: agreeableness, openness to experience, conscientiousness, extraversion, and neuroticism. Five research hypotheses are accepted. Specifically, openness to experience, conscientiousness, extraversion, and agreeableness have positive impacts on job performance of salesperson working in machinery industry in Vietnam. However, neuroticism has a negative impact on job performance of salesperson. This research results indicate the level of impact of personality traits on the sales staff performance in machinery industry. Many people apply to this profession as a career choice. Each occupation is suitable for certain personality trait, which changes very little during adulthood. Research also shows that each personality trait always has its strengths and weaknesses. The educational environment should create conditions for learners to develop their character in a natural way.