• KIPS Transactions on Software and Data Engineering
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• v.11 no.7
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• pp.273-282
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• 2022

Testing approaches for configurable software product lines differs significantly from a single software testing, as it requires consideration of common parts used by all member products of a product line and variable parts shared by some or a single product. Test coverage is a measure of the adequacy of testing performed. Test coverage measurements are important to evaluate the adequacy of testing at the software product line level, as there can be hundreds of member products produced from configurable software product lines. This paper proposes a method for measuring code coverage at the product line level in configurable software product lines. The proposed method tests the member products of a product line after hierarchizing member products based on the inclusion relationship of the selected features, and quantifies SPL(Software Product Line) test coverage by synthesizing the test coverage of each product. As a result of applying the proposed method to 11 configurable software product line cases, we confirmed that the proposed method could quantitatively visualize how thoroughly the SPL testing was performed to help verify the adequacy of the SPL testing. In addition, we could check whether the newly performed testing for a member product covers the newly added code parts of a feature.

• Particle and aerosol research
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• v.18 no.2
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• pp.23-35
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• 2022

Recently, passengers using public transport are concerned about the effects of COVID-19 and fine dust. Therefore, from February 2020 to February 2021, we investigated whether SARS-CoV-2 RNA was detected even after disinfection in 55 public transportation places visited by confirmed patients in Seoul. 34 air samples and 702 object surface samples were collected and tested with RT-PCR, one surface sample was positive. In addition, preemptive investigations were conducted in 22 subway trains that passengers were being on board at that time. 1,018 preemptive tests were performed, and all were negative. Although PM-2.5 is dangerous in itself, it can be a potential carrier of viruses. It seemed that a solution was needed as one line continuously exceeded the criteria of PM-2.5. Through this study, it is judged that cluster infection in public transportation can be prevented if efforts to reduce the concentration of fine dust, appropriate disinfection management, and personal disinfection such as wearing a mask in public transportations.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.35 no.4
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• pp.398-406
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• 2022

In order to increase the electrochemical performance of thermal battery anode, LIFT anode having the same weight but a larger lithium content in electrodes was fabricated by mixing lithium, iron and titanium. By applying these electrodes, a single cell and a thermal battery were prepared, and the effect of LIFT anode on electrochemical performance was evaluated. The LIFT-applied single cell presented a better cell performance than LIFe-applied single cell at 500℃ and 550℃. The discharge performance of LIFT-applied single cell, which included the operating time (787s), specific capacity (1,683 Asg^-1), and electrode utilization (80.7%), was improved collectively compared to the LIFe applied single cell (736s, 1,245 As g^-1, and 74.6%) at 500℃. As the discharge progressed, the internal resistance of LIFT anode decreased, because the lithium migration path was formed due to the presence of large titanium particles among iron particles. These results were analyzed in terms of the microstructure of electrode using SEM. Energy density of LIFT-applied single cell also increased by 10% to 142.1 Wh kg^-1 compared to that of LIFe-applied single cell (127.4 Wh kg^-1). In addition, the LIFT-applied single cell presented a stable discharge performance for 6,500s without a short circuit which could occur by molten lithium under an open circuit voltage condition with a high pressure (4 kgf cm^-2). As observed in the high temperature thermal battery performance tests, the voltage and specific capacity of LIFT-applied thermal battery are superior to those of LIFe-applied thermal batteries, indicating that the energy density of LIFT-applied thermal batteries should remarkably increase.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.2
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• pp.133-142
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• 2022

The purpose of this study is to develop an impact crusher with a radial rotating plate installed at the bottom, which is a shock absorber that can produce high-quality recycled coarse aggregate for concrete and to verify the effect of improving the quality performance of recycled coarse aggregate and its applicability through concrete tests. As a result, it showed improved quality in all items such as absolute dry density, absorption rate, abrasion resistance, Particle shape judgment rate, amount lost in the 0.08 mm sieve passing test, alkali aggregate reaction, clay mass, stability, and impurity content, and it was found to meet the criteria of recycled aggregate quality standards. In addition, the air volume and slump of concrete to which recycled coarse aggregate is applied meet all domestic standards. According to the test results of the compressive strength characteristics by age of concrete according to the mixing ratio of the recycled coarse aggregate, it was confirmed that the mixing ratio of the recycled coarse aggregate was applicable up to 60 %.

• Journal of the Korea Society of Computer and Information
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• v.27 no.7
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• pp.1-7
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• 2022

Recently, as the use of applications such as big data programs and machine learning programs that are driven while generating large amounts of data in the program itself becomes common, the existing main memory alone lacks memory, making it difficult to execute the program quickly. In particular, the need to derive results more quickly has emerged in a situation where it is necessary to analyze whether the entire sequence is genetically altered due to the outbreak of the coronavirus. As a result of measuring performance by applying large-capacity data to a computing system equipped with a self-developed memory pool MOCA host adapter instead of processing large-capacity data from an existing SSD, performance improved by 16% compared to the existing SSD system. In addition, in various other benchmark tests, IO performance was 92.8%, 80.6%, and 32.8% faster than SSD in computing systems equipped with memory pool MOCA host adapters such as SortSampleBam, ApplyBQSR, and GatherBamFiles by task of workflow. When analyzing large amounts of data, such as electrical dielectric pipeline analysis, it is judged that the measurement delay occurring at runtime can be reduced in the computing system equipped with the memory pool MOCA host adapter developed in this research.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.4
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• pp.1-10
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• 2022

In this study, to evaluate the possibility of using a steel spring as a displacement-dependent damping device, tensile loading and cyclic loading tests were performed. The main experimental variables were the type of steel (SAE9254 and SS275), the spring constant (700 N/mm, 1,000 N/mm, and 1,400 N/mm), and the presence or absence of heat treatment for SAE9254. As a result of the tensile test, the ratios of the measured spring constant to the design spring constant of the steel springs made with SAE9254 ranged from 1.08 to 1.13, while the ratios of the design spring constant and the measured spring constant of the steel springs made with SS275 ranged from 0.86 to 0.97. After yielding, the slope values of the load-displacement curve of the SAE9254 with/without heat treatment were about 240~251 N/mm and 92 N/mm, respectively, but the slope values of the load-displacement response of SS275 were almost zero. According to the uniaxial cyclic loading test results, all specimens were satisfied with three conditions for a displacement-dependent damping device in KDS 41 17 00 (2019): the maximum force and minimum force at zero displacement, the maximum force and minimum force at the maximum displacement, and the energy dissipation capacity. In addition, the equivalent damping ratios of steel springs made with SAE9254(non-heat treatment) and SS275 were approximately 2.8 times and 1.9 times greater, respectively, than that of steel springs made with SAE9254.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.4
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• pp.20-29
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• 2022

The operational modal analysis (OMA) technique, which extracts the modal parameters of a structural system using ambient vibrations, has been actively developed as a field of structural health monitoring of cable-supported bridges. In this paper, the short and long-term modal parameters of a cable-stayed bridge were evaluated using the acceleration data obtained from the two ambient vibration tests (AVTs) and three years of continuous measurements. A total of 27 vertical modes and 1 lateral mode in the range 0.1 ~ 2.5 Hz were extracted from the high-resolution AVTs which were conducted in the 6th and 19th years after its completion. Existing OMA methods such as Peak-Picking (PP), Eigensystem Realization Algorithm with Data Correlation (ERADC), Frequency Domain Decomposition (FDD) and Time Domain Decomposition (TDD) were applied for modal parameters extraction, and it was confirmed that there was no significant difference between the applied methods. From the correlation analysis between long-term natural frequencies and environmental factors, it was confirmed that temperature change is the dominant factor influencing natural frequency fluctuations. It was revealed that the decreased natural frequencies of the bridge were not due to changes in structural performance and integrity, but to the environmental effects caused by the temperature difference between the two AVTs. In addition, when the TDD technique is applied, the accuracy of extracted mode shapes is improved by adding a proposed algorithm that normalizes the sequence so that the autocorrelations at zero lag equal 1.

• Korean Journal of Optics and Photonics
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• v.33 no.5
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• pp.218-229
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• 2022

We have investigated reliable inspection methods for finding the defects generated during the manufacturing process of lightweight, large-aperture satellite telescope mirrors using silicon carbide, and we have measured the basic physical properties of the mirrors. We applied the advanced ceramic material (ACM) method, a combined method using liquid-silicon penetration sintering and chemical vapor deposition for the carbon molded body, to manufacture four SiC mirrors of different sizes and shapes. We have provided the defect standards for the reflectors systematically by classifying the defects according to the size and shape of the mirrors, and have suggested effective nondestructive methods for mirror surface inspection and internal defect detection. In addition, we have analyzed the measurements of 14 physical parameters (including density, modulus of elasticity, specific heat, and heat-transfer coefficient) that are required to design the mirrors and to predict the mechanical and thermal stability of the final products. In particular, we have studied the detailed measurement methods and results for the elastic modulus, thermal expansion coefficient, and flexural strength to improve the reliability of mechanical property tests.

• The Journal of the Acoustical Society of Korea
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• v.40 no.3
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• pp.201-212
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• 2021

The present study was conducted as a pilot investigation to suggest the standards of acoustic performance for classrooms suitable for incomplete hearing people such as children under 9 years of age. Subjective evaluations such as questionnaire and speech intelligibility test were conducted to 264 students at two elementary schools in Cheong-ju in order to analyze the characteristics of the listening environment in the classrooms of the lower grades in elementary school. The survey was undertaken with a total of 264 students at two elementary schools in Cheong-ju, and investigated their satisfaction with the classroom listening environment. As a result, students responded that the most helpful information type for understanding class content is the voice of teacher. In addition, the volume of the current teacher's voice is normal, and the level of clarity is highly satisfactory. As for the acoustic performance of the classroom, the opinion that the noise was normal and the reverberation was very short was found to be dominant in overall satisfaction with the listening environment. Meanwhile, as a result of speech intelligibility test using the word list selected for the lower grade students of elementary school, it could be inferred that the longitudinal axis distance from the sound source in the case of 8-year-olds is a factor that affects speech recognition.

• Journal of Life Science
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• v.31 no.12
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• pp.1100-1109
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• 2021

The halophyte Artemisia scoparia is an edible medicinal plant, with insecticidal, anti-inflammatory, anticholesterol, antipyretic, and antibacterial effects. The aim of this study was to assess the inhibitory effect of crude extract and solvent-partitioned fractions obtained from A. scoparia on MMP-2 and MMP-9 activity in phorbol-12-myristate-13-acetate (PMA)-stimulated human fibrosarcoma HT-1080 cells using four different activity tests: gelatin zymography, MMP enzyme-linked immunosorbent assay (ELISA), wound healing assay, reverse transcription-polymerase chain reaction (RT-PCR), and Western blot assay. A. scoparia samples were extracted twice with methylene chloride (MC) and twice with methanol (MeOH). After the MC and MeOH crude extracts were combined, the combined crude extracts showed a significant inhibitory effect against MMP-2 and MMP-9 enzymes. They were then fractionated into n-hexane, 85% (v/v) aqueous methanol (85% (v/v) aq.MeOH), n-butanol, and water according to solvent polarity. Among the four solvent-partitioned fractions, n-hexane and 85% (v/v) aq. MeOH fractions significantly inhibited MMP-2 and MMP-9 activity and cell mobility. In addition, the n-hexane and 85% (v/v) aq.MeOH fractions effectively inhibited MMP-2 and -9 activity in the gelatin zymography and MMP ELISA assay. In the wound healing assay, RT-PCR, and Western blot assay, all solvent-partitioned fractions, except the H₂O fraction, significantly suppressed cell migration, as well as the expression levels of MMP-2 and -9 mRNA and proteins.