• Journal of the Korea Institute of Building Construction
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• v.23 no.3
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• pp.231-240
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• 2023

In this research, our goal was to explore the potential use of cement mortar augmented with liquid red mud. To facilitate this, we neutralized liquid red mud(LR) - exhibiting a pH of 10-12 - using sulfuric acid to yield sulfuric acid neutralized red mud(SR). We then evaluated the flow, setting time, and compressive strength of the cement mortar combined with liquid red mud, while also performing a thorough examination of its chemical properties through X-ray diffraction(XRD) and scanning electron microscopy(SEM). The flow tests indicated a decrease in flow values for both MS-LR and MS-SR in comparison to the Plain. Analogously, the setting time for MS-LR and MS-SR was found to be abbreviated when juxtaposed with the Plain. With regards to compressive strength, MS-LR demonstrated a surge in strength at the 1-day mark, while MS-SR displayed a diminution at the 1-day and 3-day timepoints compared to the Plain. XRD analysis illustrated that after 28 days, the XRD patterns of Plain and MS-SR bore significant resemblance, though a new peak was detected in MS-LR. SEM imagery highlighted that the microstructures of Plain and MS-SR were alike, but MS-LR manifested a distinct microstructure, characterized by a finely fibrous formation. Based on these observations, we infer that the replacement of cement mortar with liquid red mud neutralized with sulfuric acid contributes to a noticeable enhancement in strength, thereby verifying its suitability for this application.

• Journal of Digital Convergence
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• v.20 no.1
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• pp.203-211
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• 2022

This study is to examine the causes of research misconduct such as plagiarism, forgery, redundant publication, unfair author expression, and incapacitation of the research ethics system of university researchers and to suggest improvement plan. It basically relied on literature research. In order to supplement the deficiencies in literature research, I sought advice from an expert professor who had experience working in a research-related field in university or who is currently in a position related to research ethics through the delphi-method. As a result of the study, from the perspective of individual researchers, the complacent attitude, dishonesty, and greed for research funds were identified as the main reasons. In terms of organization, it was analyzed for reasons such as lack of detail and application of regulations, lack of verification system, and performance-oriented research environment. In order to overcome research misconduct caused by the researcher's personal reasons, regularization, increase in the number of research ethics education, and strengthening personal penalties were suggested. As a way to overcome irregularities arising from institutional reasons, the reinforcement of the verification system, the reinforcement of the whistle-blower's personal protection system, the omission of promotion, and the quality and quantitative balance of research evaluation was suggested.

• Nuclear Engineering and Technology
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• v.11 no.3
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• pp.203-212
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• 1979

The thermal decomposition of simulated Magnox highly active waste and of HARVEST feed slurries (SW and SG) which include tile glass forming chemicals has been studied. The waste and the slurries are almost completely calcined by 500-55$0^{\circ}C$. The colour of the solids from the slurries varies little until about 90$0^{\circ}C$ when it darkens considerably. The slurries begin to vitrify at this temperature and are completely vitrified at 1000-105$0^{\circ}C$. On the other hand. the sulphate impurity in SN slurry causes a yellow phase to separate above 75$0^{\circ}C$. The density of the intermediate solids is fairly low until 650$^{\circ}$-$700^{\circ}C$ is reached. This temperature seems to mark the onset of fluxing as tile density rises quickly to 2g/㎤ at 700$^{\circ}$ -80$0^{\circ}C$. The strengh of the solids decreases with temperature up to 50$0^{\circ}C$, and then rises as the solids begin to sinter. Below 50$0^{\circ}C$ the SN solids are the stronger. suggesting that the impurity renders this silica more reactive.

• Korea Trade Review
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• v.41 no.5
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• pp.1-14
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• 2016

Consumers have been increasing their interests in firms' ethicality as well as in the features of the firms' products when they decide to purchase a certain product. Recently, fair trade is considered to be a type of ethical marketing in the business-to-consumer market. In this regard, the effects of fair trade-based marketing on firm performance have become the center of academic and managerial concerns. Despite this importance, few studies have investigated whether fair-trade is a source of competitive advantage or just a cost of doing business. The present research attempts to provide evidence of how fair trade-based marketing influences competitive advantage. Two experimental studies were conducted to explore consumers' purchase intention, which can be a proxy of competitive advantage, in a foreign product-consumption context. Drawing on the stakeholder theory, the first study was performed to examine the effects of fair trade marketing on consumers' purchase intention through a within-subjects design. In addition, building on the signal theory, the second study was executed to test the effects of a fair trade mark on consumers' purchase intention. The findings of the current research reveal that consumers prefer fair trade-based products to others and that when it comes to fair trade-certified products, consumers are more likely to purchase products with that certification than otherwise, even when those products are sold at higher costs than rival products. Interestingly, the results of this research present that there is a significant difference of consumers' purchase intention of a fair trade-based product between two different marketers. This implies that fair trade-based products should be differentially distributed and targeted at a certain type of consumers.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.3
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• pp.160-174
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• 2023

LiDAR plays a key role in autonomous vehicles, and to improve its visibility, it is necessary to improve its performance and the detection objects. Accordingly, this study proposes a shape for traffic safety signs that is advantageous for self-driving vehicles to recognize. Improvement plans are also proposed using a shape-recognition algorithm based on point cloud data collected through LiDAR sensors. For the experiment, a DBSCAN-based road-sign recognition and classification algorithm, which is commonly used in point cloud research, was developed, and a 32ch LiDAR was used in an actual road environment to conduct recognition performance tests for 5 types of road signs. As a result of the study, it was possible to detect a smaller number of point clouds with a regular triangle or rectangular shape that has vertical asymmetry than a square or circle. The results showed a high classification accuracy of 83% or more. In addition, when the size of the square mark was enlarged by 1.5 times, it was possible to classify it as a square despite an increase in the measurement distance. These results are expected to be used to improve dedicated roads and traffic safety facilities for sensors in the future autonomous driving era and to develop new facilities.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.20 no.1
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• pp.23-38
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• 2009

The purpose of this study was to suggest the collection codes and simplification of call numbers for children's easy access to the children's materials. The classification schemes, author tables, expansion of classification schemes, collections codes, classification numbers used in domestic and foreign children's libraries were surveyed through questionnaires and interviewing with librarians. As a result, in foreign children's libraries, it was common practice to shelve children's materials separately into various collections and sub-collections, to mark the spine with collection code and the lead characters of the author's last name, and not to stick with their classification scheme when it comes to highly circulated children's materials such as fiction, picture book, biographies and so on. Also, in domestic children's libraries, it was found that a collection code was used a few and each call number was almost assigned by KDC number. Therefore, it was suggested that the types and codes of collection and sub-collection were divided as non-fiction, fiction, fiction/mystery, fiction/science fiction, picture book, cartoon, language, folks and fairy tales, biographies, legend, concept book, holiday, award, dinosaur, insect, DIY, transportation, tall book, pop-up, story book, board book, reference, magazine, series, new book, video, and audio and were easily expanded by combining age tables or fiction genre. Also, new simplifying methods of building call numbers with collection codes were suggested.

• The Journal of the Convergence on Culture Technology
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• v.9 no.2
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• pp.525-531
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• 2023

In Korea, which is entering a super-aged society, the number of elderly patients who have difficulty walking independently is expected to increase rapidly, and it is necessary to develop wheelchair products with various functions to improve the quality of life of people with walking disabilities. Recently, wheelchair power assist devices that provide propulsion power by being attached to a manual wheelchair has been developed and is entering the domestic and global markets. In this study, we compared and analyzed the process of obtaining medical device certification for wheelchair power assist devices in Korea, the United States, and Europe. In Korea, a Class 2 medical device certification process was developed in 2021, and in the US FDA, it corresponds to Class 2 like the existing electric wheelchair and must pass the 510k certification process. In the case of Europe, it is uniquely regulated as Class I, and the CE mark can be attached through a relatively easy self-declaration of conformity. The Korean medical device industry, which is struggling with MDR certification, a new European medical device regulation, should pay attention to the relatively easy entry into the global market for wheelchair power assist products.

• Journal of The Korean Astronomical Society
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• v.56 no.2
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• pp.169-185
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• 2023

The GMT-Consortium Large Earth Finder (G-CLEF) is the first instrument for the Giant Magellan Telescope (GMT). G-CLEF is a fiber feed, optical band echelle spectrograph that is capable of extremely precise radial velocity measurement. G-CLEF Flexure Control Camera (FCC) is included as a part in G-CLEF Front End Assembly (GCFEA), which monitors the field images focused on a fiber mirror to control the flexure and the focus errors within GCFEA. FCC consists of an optical bench on which five optical components are installed. The order of the optical train is: a collimator, neutral density filters, a focus analyzer, a reimager and a detector (Andor iKon-L 936 CCD camera). The collimator consists of a triplet lens and receives the beam reflected by a fiber mirror. The neutral density filters make it possible a broad range star brightness as a target or a guide. The focus analyzer is used to measure a focus offset. The reimager focuses the beam from the collimator onto the CCD detector focal plane. The detector module includes a linear translator and a field de-rotator. We performed thermoelastic stress analysis for lenses and their mounts to confirm the physical safety of the lens materials. We also conducted the global structure analysis for various gravitational orientations to verify the image stability requirement during the operation of the telescope and the instrument. In this article, we present the opto-mechanical detailed design of G-CLEF FCC and describe the consequence of the numerical finite element analyses for the design.

• Journal of Trauma and Injury
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• v.37 no.1
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• pp.60-66
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• 2024

Purpose: This study investigated changes in interpersonal violence and utilization of trauma recovery services during the COVID-19 pandemic. At an urban level I trauma center, trauma recovery services (TRS) provide education, counseling, peer support, and coordination of rehabilitation and recovery to address social and mental health needs. The COVID-19 pandemic prompted considerable changes in hospital services and increases in interpersonal victimization. Methods: A retrospective analysis was conducted between September 6, 2018 and December 20, 2020 for 1,908 victim-of-crime patients, including 574 victims of interpersonal violence. Outcomes included length of stay associated with initial TRS presentation, number of subsequent emergency department visits, number of outpatient appointments, and utilization of specific specialties within the year following the initial traumatic event. Results: Patients were primarily female (59.4%), single (80.1%), non-Hispanic (86.7%), and Black (59.2%). The mean age was 33.0 years, and 247 patients (49.2%) presented due to physical assault, 132 (26.3%) due to gunshot wounds, and 76 (15.1%) due to sexual assault. The perpetrators were primarily partners (27.9%) or strangers (23.3%). During the study period, 266 patients (mean, 14.9 patients per month) presented before the declaration of COVID-19 as a national emergency on March 13, 2020, while 236 patients (mean, 25.9 patients per month) presented afterward, representing a 74.6% increase in victim-of-crime patients treated. Interactions with TRS decreased during the COVID-19 period, with an average of 3.0 interactions per patient before COVID-19 versus 1.9 after emergency declaration (P<0.01). Similarly, reductions in length of stay were noted; the pre-COVID-19 average was 3.6 days, compared to 2.1 days post-COVID-19 (P=0.01). Conclusions: While interpersonal violence increased, TRS interactions decreased during the COVID-19 pandemic, reflecting interruption of services, COVID-19 precautions, and postponement/cancellation of elective visits. Future direction of hospital policy to enable resource and service delivery to this population, despite internal and external challenges, appears warranted.

• Korean Journal of Radiology
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• v.20 no.5
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• pp.709-718
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• 2019

Objective: To investigate the association of myocardial blood flow (MBF) quantified by dynamic computed tomography (CT) myocardial perfusion imaging (MPI) with troponin level and left ventricle (LV) function in patients with ST-segment elevated myocardial infarction (STEMI). Materials and Methods: Thirty-five STEMI patients who successfully had undergone reperfusion treatment within 1 week of their infarction were consecutively enrolled. All patients were referred for dynamic CT-MPI. Serial high-sensitivity troponin T (hs-TnT) levels and left ventricular ejection fraction (LVEF) measured by echocardiography were recorded. Twenty-six patients with 427 segments were included for analysis. Various quantitative parameters derived from dynamic CT-MPI were analyzed to determine if there was a correlation between hs-TnT levels and LVEF on admission and again at the 6-month mark. Results: The mean radiation dose for dynamic CT-MPI was 3.2 ± 1.1 mSv. Infarcted territories had significantly lower MBF (30.5 ± 7.4 mL/min/100 mL versus 73.4 ± 8.1 mL/min/100 mL, p < 0.001) and myocardial blood volume (MBV) (2.8 ± 0.9 mL/100 mL versus 4.2 ± 1.1 mL/100 mL, p = 0.044) compared with those of reference territories. MBF showed the best correlation with the level of peak hs-TnT (r = -0.682, p < 0.001), and MBV showed a moderate correlation with the level of peak hs-TnT (r = -0.437, p = 0.026); however, the other parameters did not show any significant correlation with hs-TnT levels. As for the association with LV function, only MBF was significantly correlated with LVEF at the time of admission (r = 0.469, p = 0.016) and at 6 months (r = 0.585, p = 0.001). Conclusion: MBF quantified by dynamic CT-MPI is significantly inversely correlated with the level of peak hs-TnT. In addition, patients with lower MBF tended to have impaired LV function at the time of their admission and at 6 months.