• Journal of Information Technology Services
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• v.20 no.5
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• pp.89-104
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• 2021

Food delivery service combined with IT technology and HMR (Home Meal Replacement) are rapidly growing due to the COVID-19. Recently, the demand for salads along with HMR has increased among office workers in their 20s and 30s who are interested in health and beauty. Freshcode is a food startup with 6 years of experience that started selling salad products through O2O service. Freshcode applied for a patent for a service that collects orders from nearby areas and delivers them on the same day to a designated delivery address 'FCOSPOT' to save shipping costs. In March 2021, in recognition of the growth potential of the regular delivery service, Freshcode received an investment of 6 billion won in Series A. This study may have practical implications to early-stage startups and scale-up stage startups through a longitudinal case study on the growth of a single company. As for the research method, the lean startup methodology and lean canvas were used in the early stage of startup. In particular, the process of the build-measure and learn feedback-loop, which is the core of lean startup methodology, was applied to each major decision-making step. In the scale-up stage after 5 years, the business model canvas was used to schematize the growth as a food online O2O platform to verify continuous innovation. This case study has three main findings. First, the idea of 'FCOSPOT' was successfully implemented through the Lean Startup methodology. Second, Freshcode demonstrated the scalability of the differentiated business model of shared base delivery O2O. Third, a key factor of success was the digital integrated communication operation strategy that maximizes the experience for the created customers.

• Journal of the Korea Society of Computer and Information
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• v.27 no.7
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• pp.75-82
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• 2022

There are various exhibition halls, shopping malls, theme parks around us and analysis of interest in exhibits or contents is mainly done through questionnaires. These questionnaires are mainly depend on the subjective memory of the person being investigated, resulting in incorrect statistical results. Therefore, it is possible to identify an exhibition space with low interest by tracking the movement and counting the number of visitors. Based on this, it can be used as quantitative data for exhibits that need replacement. In this paper, we use deep learning-based artificial intelligence algorithms to recognize visitors, assign IDs to the recognized visitors, and continuously track them to identify the movement path. When visitors pass the counting line, the system is designed to count the number and transmit data to the server for integrated management.

• Advances in nano research
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• v.13 no.2
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• pp.187-197
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• 2022

The synthesis of organic and hybrid organic-inorganic perovskites directly from solution improves the cost- and energy-efficiency of processing. To date, numerous research efforts have been devoted to investigating the influence of the various solvent parameters for the synthesis of lead halide perovskites, focused on the effects of different single solvents on the efficiency of the resulting perovskites. In this work, we investigated the effect of solvent blends for the first time on the structure and phase of perovskites produced via the Lewis base vapor diffusion method to develop a new synthetic approach for water-stable CsPbBr₃ particles with nanometer-sized dimensions. Solvent blends prepared with DMF and water-miscible solvents with different Gutmann's donor numbers (D_N) affect the Pb ions differently, resulting in a variety of lead bromide species with various colors. The use of a DMF/isopropanol solvent mixture was found to induce the formation of the Ruddlesden-Popper perovskite based on lead bromide. This perovskite undergoes a blue color shift in the solvated state owing to the separation of nanoplatelets. In contrast, the replacement of isopropanol with DMSO, which has a high DN, induces the formation of spherical CsPbBr₃ perovskite nanoparticles that exhibit green emission. Finally, the integration of acetone in the solvent system leads to the formation of lead bromide complexes with a yellow-orange color and the perovskite CsPbBr₃.

• Fashion & Textile Research Journal
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• v.24 no.2
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• pp.249-259
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• 2022

To analyze recent changes in designer-specific garment composition, detail, and design elements of jackets, we classified jackets from the Paris Haute Couture Collection from 2000 S/S to 2019 F/W according to their designers and examined their characteristics. Our analysis of the jackets by Armani, Chanel, Dior, Jean-Paul Gaultier, and Valentino shows that the hour-glass silhouette was most common in Armani, Chanel, Dior, Jean-Paul Gaultier and Valentino jackets; Chanel used more straight silhouettes compared to other designers. Most jackets, regardless of the designer, had midlength waist-to-bottom, tight sleeves fitted to the body, natural shoulder shape, and solid color. Moreover, woven fabric was the most common material. Jackets with no collar were the most common for Armani, tailored collars for Dior and Jean-Paul Gaultier, and standing collars for Chanel and Valentino. For the closure method, Armani used hook-and-eye, Chanel, Jean-Paul Gaultier, Valentino used button closures, and Dior used snap closures the most. New design attempts by designers are bringing details and design elements together. In an era characterized by an abundance of designs and frequent replacement of each brand's creative designers, it is important to create and maintain a brand's unique design identity and philosophy that can meet consumers' elevated standards, which tend to be biased towards new and stimulating designs due to the development of the IT industry.

• Clinical and Experimental Pediatrics
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• v.65 no.4
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• pp.188-193
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• 2022

Background: Respiratory distress syndrome (RDS) is a common cause of hospitalization and death in preterm infants who require surfactant treatment and respiratory support. Purpose: This study aimed to compare the clinical outcomes of minimally invasive surfactant therapy (MIST) and the INtubation, SURfactant administration, and Extubation (INSURE) technique in preterm infants with RDS. Methods: In this clinical trial, 112 preterm infants born at 28-36 weeks of gestation and diagnosed with RDS randomly received 200-mg/kg surfactant by MIST or the INSURE method. In the MIST group, surfactant was administered using a thin catheter (5F feeding tube); in the INSURE group, surfactant was administered after intubation using a feeding tube and the tracheal tube was removed after positive pressure ventilation was started. Nasal continuous positive airway pressure was applied in both groups for respiratory support and the postprocedure clinical outcomes were compared. Results: The mean hospitalization time was shorter for infants in the MIST group than for those in the INSURE group (9.19±1.72 days vs. 10.21±2.15 days, P=0.006). Patent ductus arteriosus was less frequent in the MIST group (14.3% vs. 30.4%, P=0.041). Desaturation during surfactant administration occurred less commonly in the MIST group (19.6% vs. 39.3%, P=0.023). There were no significant intergroup differences in other early or late complications. Conclusion: These results suggest that surfactant administration using MIST could be a good replacement for INSURE in preterm infants with RDS since its use reduced the hospitalization time and the number of side effects.

• Biomedical Science Letters
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• v.28 no.3
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• pp.195-199
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• 2022

The use of copper antibacterial films as an effective infection prevention method is increasing owing to its ability to reduce the risk of pathogen transmission. In this study, we evaluated the bacterial contamination of the antibacterial copper membrane attached to a door handle at a university over time. Six mounting locations with high floating population were selected. In three sites, the door handles with the antibacterial film were exposed, while the remaining three were not attached with the antibacterial films. On days 7 and 14, isolated bacterial strains were inoculated in BHI broth and agar, respectively. Colony-forming units (CFU) were determined after incubation. Strain identification was performed using bacterial 16s rRNA PCR and sequencing. Results showed that the bacterial population on day 14 significantly increased from 6 × 10⁹ CFU/mL (day 7) to 2 × 10¹⁰ CFU/mL. Furthermore, strain distribution was not different between the on and off the copper antibacterial film groups. In conclusion, although copper has an antibacterial activity, microbial contamination may occur with prolonged use.

• Food Science of Animal Resources
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• v.43 no.3
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• pp.428-440
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• 2023

Global meat consumption is increasing worldwide, however, supply remains lacking. Several alternative protein sources, such as cultured meat, plant-based protein production, and edible insects, have been proposed to overcome this shortage. Interestingly, edible insects are characterized by superior digestive and absorptive qualities that make them the ideal replacement for traditional protein production. This study aims to further the processing ability of insect protein by investigating the effects of various pre-treatment methods, such as blanching (HB), roasting (HR), and superheated steam (HS), on the nutritional properties and physicochemical characteristics of proteins extracted from Hermetia illucens larvae. The drying rate, pH value, color analysis, amino and fatty acid profile, as well as bulk density, shear force, and rehydration ratios of the above pre-treatment methods, were explored. HS was found to have the highest drying rate and pH value analysis showed that HB and HS samples have significantly higher values compared to the other modalities. Raw edible insects had the highest value in the sum of essential amino acid (EAA) and EAA index when compared to EAAs. HB and HS showed significantly lower bulk density results, and HS showed the highest shear force and the highest value in rehydration ratio, regardless of immersion time. Therefore, taking the above results together, it was found that blanching and superheated steam blanching pre-treatment were the most effective methods to improve the processing properties of H. illucens after hot-air drying.

• Steel and Composite Structures
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• v.45 no.3
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• pp.389-408
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• 2022

Residual capacity is defined as the load carrying capacity of an RC column after undergoing severe damage. Evaluation of residual capacity of RC columns is necessary to avoid damage initiation in RC structures. The central aspect of the current research is to propose an empirical formula to estimate the residual capacity of RC columns after undergoing severe damage. This formula facilitates decision making of whether a replacement or a repair of the damaged column is adequate for further use. Available literature mainly focused on the simulation of explosion loads by using simplified pressure time histories to develop residual capacity of RC columns and rarely simulated the actual explosive. Therefore, there is a gap in the literature concerning general relation between blast damage of columns with different explosive loading conditions for a reliable and quick evaluation of column behavior subjected to blast loading. In this paper, the Arbitrary Lagrangian Eulerian (ALE) technique is implemented to simulate high fidelity blast pressure propagations. LS-DYNA software is utilized to solve the finite element (FE) model. The FE model is validated against the practical blast tests, and outcomes are in good agreement with test results. Multivariate linear regression (MLR) method is utilized to derive an analytical formula. The analytical formula predicts the residual capacity of RC columns as functions of structural element parameters. Based on intensive numerical simulation data, it is found that column depth, longitudinal reinforcement ratio, concrete strength and column width have significant effects on the residual axial load carrying capacity of reinforced concrete column under blast loads. Increasing column depth and longitudinal reinforcement ratio that provides better confinement to concrete are very effective in the residual capacity of RC column subjected to blast loads. Data obtained with this study can broaden the knowledge of structural response to blast and improve FE models to simulate the blast performance of concrete structures.

• Journal of the Korean Geotechnical Society
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• v.26 no.12
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• pp.61-70
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• 2010

A series of shaking table tests were conducted to estimate the seismic performance of soft ground deposits improved by stone column. The amplification of acceleration, shear strain, and shear wave velocity were evaluated to compare the seismic response of unimproved ground deposits with that of improved ground deposits. From the test results, it was shown that the stone column can prevent large shear deformation in ground deposits. However, it was also found that the acceleration of improved ground deposits may be amplified more than that of unimproved ground deposits when it was subjected to short periodic seismic wave. The results suggest that it is necessary to perform the ground response analysis with model experiments for both unimproved and improved ground deposits to evaluate the effect of stone column on the seismic performance of improved ground deposits.

• Journal of the Korea Institute of Building Construction
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• v.23 no.4
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• pp.359-367
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• 2023

This experimental study investigates the replacement of conventional Portland cement and sand with non-sintered cement and ferro-nickel slag to formulate eco-friendly cement mortar. The examination aimed to understand the strength properties of non-sintered cement mortar using ferro-nickel slag as fine aggregate by classifying mortar production types, fine aggregates, and curing methodologies. From flexural and compressive strength tests, it was observed that non-sintered cement mortars, incorporating ferro-nickel slag as fine aggregate, exhibited superior strength when compared to both plain mortar and steam-cured non-sintered mortar. This increased strength is attributed to the influence of the particle size, density, and absorption capabilities of the ferro-nickel slag. Furthermore, X-ray Diffraction(XRD) analyses of the mortars verified the presence of MgO, a component of ferro-nickel slag, in the form of a composite oxide. This finding substantiates the consistent strength manifestation of non-sintered cement mortars utilizing ferro-nickel slag as a fine aggregate.