• Resources Recycling
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• v.30 no.2
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• pp.14-23
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• 2021

To investigate the potential for leaching of heavy metals by bacteria from ores stacked on actual mining sites, leaching tests of a complex metallic ore (Pb-Zn-As ore) were conducted over 60 days using acidophile bacteria Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans under initial acidic conditions. Initially, a small amount of heavy metals was leached due to the initial acidic conditions. After 20 days, when A. thiooxidans in the reactor was adapted to the ore, the amount of leached heavy metals rapidly increased; the concentrations of leached arsenic, iron, and zinc reached a maximum of 2800, 3700, and 2500 mg/L, respectively. On the other hand, in the presence of A. ferrooxidans or in the control test without bacteria, heavy metals, except zinc, were barely detected in leaching. Through this study, it was confirmed that (i) bacteria could leach heavy metals at mining sites under acidic conditions and (ii) leaching of heavy metals from a high arsenic-containing ore by A. thiooxidans was more significant than that by A. ferrooxidans.

• Journal of vocational education research
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• v.37 no.5
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• pp.55-78
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• 2018

The purpose of this study is to investigate the recognition of the professionalism required for strengthening the effective career guidance capacity of the secondary career teachers who are required to prepare for the coming fourth industrial revolution era. Based on these research objectives, we derived the required roles(8), the required competencies(20), and the contents(23) for enhancing professionalism by the required competencies, based on this, the questionnaire was composed and 217 respondents were collected and analyzed. First, the t-test was conducted to confirm the statistically significant difference between the current level and the important level of each content item by each role. As a result, it was found that in all roles except role of 'administrator' The t-value is statistically significant and the t-value distribution is high. Second, the demand value calculation and the priority ranking using the Borich demand calculation formula were found, and as a result, the directionality between the t value and the Borich demand was in agreement. Third, as a result of prioritizing using the Locus for Focus model, the contents of all 5 (middle school 7, high school 2) education contents were given priority. Fourth, three middle schools and five high schools were derived from the subordinate. Finally, we confirmed the relevance of the contents of education to actual educational necessity. Although this study has many limitations and limitations due to the fact that there are few prior data due to the segmentation of the subject related to the 4th Industrial Revolution and career guidance, it is necessary to develop educational training program I hope to be able to use it as basic data of various follow-up studies and make some suggestions.

• Korean Journal of Environmental Agriculture
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• v.37 no.3
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• pp.197-206
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• 2018

BACKGROUND: The present study aimed to examine the crops capable of growing and adapting to the external environment and various stresses of reclaimed agriculture land for the development of high value-added agricultural utilization technology based on reclaimed land through standardization and empirical study of cultivation environment for cultivating crops. METHODS AND RESULTS: Two crops namely turnips and beets were selected for the salt tolerance test of soil environmental conditions on reclaimed land. Turnip and beet seedlings were planted on the soil collected at the 'Seokmun' reclaimed land. There are five treatments such as non-treatment, 1.0, 2.0 (control), 4.0 and $8.0dS{\cdot}m^{-1}$ of EC. The contents of betacyanin in beet roots was highest in control and decreased with increasing salt concentration. The GSL contents in the turnip roots waswere highest at EC 2.0 and decreased with increasing salt concentration, whereas those in turnip leaves waswere high both in the non-treated control and atthe EC 1.0-treatment. But, tThere was, however, no statistical differences among the treatments. CONCLUSION: The degree of salt tolerance of crops was examined, and the limit EC iswas expected to be $3.0{\sim}4.0dS{\cdot}m^{-1}$ as reported to date. If the soil improvement is performed and irrigation systems are used in the actual reclaimed land, the EC of supplied irrigation will be low, and desalination effecttreatment by the lower EC of the supplied irrigation on the soil will lead to more favorable soil condition of the rhizosphere and cultivation environment offor the crops than those in the port experiment. Therefore, monitoring the salinity, water content and ground water level will enable prediction of the rhizosphere environment, and setting up irrigation management and supplying irrigation will lead to crop cultivation results that are close to normal.

• Journal of the Korea Convergence Society
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• v.9 no.11
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• pp.61-68
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• 2018

In this paper, we propose a method of character detection by analyzing image enhancement and character type to detect characters in natural images that can be acquired in everyday life. The proposed method emphasizes the boundaries of the object part using the unsharp mask in order to improve the detection rate of the area to be recognized as a character in a natural image. By using the boundary of the enhanced object, the character candidate region of the image is detected using Maximal Stable Extermal Regions (MSER). In order to detect the region to be judged as a real character in the detected character candidate region, the shape of each region is analyzed and the non-character region other than the region having the character characteristic is removed to increase the detection rate of the actual character region. In order to compare the objective test of this paper, we compare the detection rate and the accuracy of the character region with the existing methods. Experimental results show that the proposed method improves the detection rate and accuracy of the character region over the existing character detection method.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.688-694
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• 2018

The mixture ratio of two-component liquid silicone is important for the inherent physical characteristics of the finished product. Therefore, it is necessary to uniformly control the ratio of the main material and the sub-material. In this paper, a mixing-ratio control system was designed, which consists of a digital flow meter and a flow control system to measure the flow rate of the raw materials and a pumping system to maintain constant pressure and transfer of the raw materials. In addition, a program was developed to control the organic interlocking and mixing ratio. For the verification of the developed system, we compared the actual weight of raw material with the value measured by the flow meter during pumping, and we measured the physical properties of the mixed material by making test samples with and without the application of the mixing-ratio improvement algorithm. The measured value was close to the reference value with a hardness range of 46-47 and tensile strength of 9.3-9.5 MPa. These results show that the mixing ratio of the liquid silicone is controlled within an error range of ${\pm}0.5%$.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.3
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• pp.242-250
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• 2019

In this paper, we propose a method to predict the failure of industrial robot using Seq2Seq (Sequence to Sequence) model, which is a model for transforming time series data among Artificial Neural Network models. The proposed method uses the data of the joint current and angular value, which can be measured by the robot itself, without additional sensor for fault diagnosis. After preprocessing the measured data for the model to learn, the Seq2Seq model was trained to convert the current to angle. Abnormal degree for fault diagnosis uses RMSE (Root Mean Squared Error) during unit time between predicted angle and actual angle. The performance evaluation of the proposed method was performed using the test data measured under different conditions of normal and defective condition of the robot. When the Abnormal degree exceed the threshold, it was classified as a fault, and the accuracy of the fault diagnosis was 96.67% from the experiment. The proposed method has the merit that it can perform fault prediction without additional sensor, and it has been confirmed from the experiment that high diagnostic performance and efficiency are available without requiring deep expert knowledge of the robot.

• The Journal of the Korea Contents Association
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• v.18 no.12
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• pp.25-34
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• 2018

With the higher competition of university environment, universities has been adapted Customer Satisfaction Index (CSI). However, the problem of CSI focuses on score and ranking announcement. In public sectors, PCSI model is used because of increasing its strategic utilization by providing diagnosis of the phenomenon and direction for future improvement through causal model analysis. The purpose of this research is to develop a measurements of university satisfaction using PCSI. This research demonstrates validity and reliability of PCSI using test-retest method using multi-group confirmatory factor analysis. The results of this research indicate that the reliability and validity of the PCSI model is verified. Service product quality, service delivery quality, environment quality and social quality have positive effects on customer satisfaction. In turn, customer satisfaction have positve effects on university performance and social performance. In conclusion, service quality, PCSI, and service performance are clarified to be appropriate components of the satisfaction survey. These results can be used to measure the satisfaction level of education at actual universities. It is expected that practical basic data can be obtained to improve the quality of university education.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.36 no.6
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• pp.457-467
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• 2018

Currently, the regulation and rules for public surveying and the UCPs (Unified Control Points) adapts those of the triangulated traverse surveying. In addition, such regulations do not take account of the unique characteristics of GNSS (Global Navigation Satellite System) surveying, thus there are difficulties in field work and data processing afterwards. A detailed procesure of GNSS processing has not yet been described either, and the verification of accuracy does not follow the generic standards. In order to propose an appropriate procedure for field surveys, we processed a short session (30 minutes) based on the scenarios similar to actual situations. The reference network in Seoul was used to process the same data span for 3 days. The temporal variation during the day was evaluated as well. We analyzed the accuracy of the estimated coordinates depending on the parameterization of tropospheric delay, which was compared with the 24-hr static processing results. Estimating the tropospheric delay is advantageous for the accuracy and stability of the coordinates, resulting in about 5 mm and 10 mm of RMSE (Root Mean Squared Error) for horizontal and vertical components, respectively. Based on the test results, we propose a procedure to estimate the daily solution and then combine them to estimate the final solution by applying the minimum constraints (no-net-translation condition). It is necessary to develop a web-based processing system using a high-end softwares. Additionally, it is also required to standardize the ID of the public control points and the UCPs for the automatic GNSS processing.

• Journal of the Korean Wood Science and Technology
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• v.47 no.2
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• pp.129-144
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• 2019

This study aimed at developing an accelerated collection method that reduces measurement and collection time by improving and complementing the desiccator method, which is mainly used for quality control in wood-based panels and furniture production sites. First, this study measured the formaldehyde emissions from the wood-based panels by grade using the desiccator method. Further, this study compared the desiccator method with the developed process and analyzed the correlation in optimal temperature, time, and exposed area. The results showed that the developed process resulted in relatively similar outcomes in comparison to the desiccator method when the temperature was $100^{\circ}C$, the time was 1 h, and two specimens were used, at which the correlation was high. To verify the developed process, this study commissioned Korea Conformity Laboratories with the standardized temperature, time, and the number of specimens to compare them with the specimen that was not used in the actual test. As a result, the correlation to the desiccator method was shown to be very high. However, the formaldehyde emission measured by the accelerated collection process was mostly higher than that measured by the desiccator method. The formaldehyde emission grades from several specimens were one level higher. However, from the perspectives of quality control, it was determined that the accelerated collection method developed in this study could be sufficiently used.

• 재활복지
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• v.21 no.3
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• pp.165-186
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• 2017

The purpose of this study was to compare adults' with intellectual disabilities voice pitch between who have choir experiences and those who do not. Participants were a total of 21 male adults with intellectual disabilities (12 choir group members and 9 non-choir group). Praat test was conducted to compare the characteristics of pitch, produced by the participants while they were singing in their comfortable pitch range. The results showed that the range of melodic contour in the choir group was broader and higher than those of the non choir group. Participants in the choir group produced a lower pitch in the beginning note, and they produced a higher pitch compared to the non-choir group on the highest and lowest note of the song. An analysis on the pitch of the individual note that the participants produced revealed a gap between the expected pitch notes and the actual notes produced while singing. In all syllables of the song, participants in the choir group showed higher accuracy of the pitch production, and significantly more accurate on the perfect fifth and eighth intervals. Regarding to the relative pitch, participants in the choir group produced significantly more accurate notes on perfect fifth, perfect fourth, and perfect eighth intervals. Findings of the study suggest that constant singing experience enable them to have pitch training. It also implies for further studies regarding to singing abilities of adults with intellectual disabilities.