• Applied Chemistry for Engineering
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• v.34 no.5
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• pp.522-528
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• 2023

In this work, adhesive tapes were prepared for the dicing process in semiconductor manufacturing. Compounds with different numbers of photoreactive groups (f = 1 to 3) were synthesized and incorporated into acrylic copolymers to formulate UV-curable acrylic adhesives. Structural confirmation of the synthesized photoreactive compounds (f = 2 or 3) was performed using nuclear magnetic resonance (NMR) spectroscopy. The introduction of the photoreactive compounds into the acrylic adhesive was accomplished by urethane reactions, and the successful synthesis of the UV-curable acrylic adhesive was verified by Fourier transform infrared (FT-IR) measurements. To evaluate the performance of the adhesive, the peel strength was evaluated before and after UV irradiation using a silicon wafer as a substrate. The adhesive exhibited high peel strength (~2000 gf/25 mm) before UV exposure, which was significantly reduced (~5 gf/25 mm) after UV exposure. Interestingly, the adhesive containing multifunctional photoreactive compounds showed the most significant reduction in peel strength. In addition, surface residue measurements by field emission scanning electron microscopy (FE-SEM) showed minimal surface residue (~0.2%) after UV exposure. Overall, these results contribute to the understanding of the behavior of UV-curable acrylic adhesives and pave the way for potential applications in semiconductor manufacturing processes.

• Journal of the Korean Geotechnical Society
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• v.39 no.12
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• pp.47-60
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• 2023

At present, in South Korea, there is a growing concern regarding solar power facilities installed on slopes because they are prone to damage caused by natural disasters, such as heavy rainfall and typhoons. Each year, these solar power facilities experience soil erosion due to heavy rainfall and foundation damage or detachment caused by strong wind loads. Despite these challenges, the interaction between the ground and structures is not adequately considered. Current analyses primarily focus on the structural stability under external loads; the overall facility site's stability-excluding the solar structures-in relation to its surrounding slopes is neglected. Therefore, in this study, we use finite-difference method analysis to simulate the behavior of the foundation and piles to assess changes in lateral displacement and bending stress in piles, as well as the safety factor of sloped terrains, in response to various influencing factors, such as pile diameter, spacing between piles, pile-embedding depth, wind loads, and dry and wet conditions. The analysis results indicate that pile spacing and wind loads significantly influence lateral displacement and bending stress in piles, whereas pile-embedding depth strongly influences the safety factor of sloped terrains. Moreover, we found that under certain conditions, the design criteria in domestic standards may not be met.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.33 no.6
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• pp.255-260
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• 2023

As demanding the detection of explosive molecules, it is required to develop rapidly and precisely responsive sensors with ultra-high sensitivity. Since two-dimensional semiconductors have an atomically thin body nature where mobile carriers accumulate, the abrupt modulation carrier in the thin body channel can be expected. To investigate the effectiveness of WSe₂ semiconductor materials as a detection material for TNT (Trinitrotoluene) explosives, WSe₂ was synthesized using thermal chemical vapor deposition, and afterward, WSe₂ FETs (Field Effect Transistors) were fabricated using standard photo-lithograph processes. Raman Spectrum and FT-IR (Fourier-transform infrared) spectroscopy reveal that the adsorption of TNT molecules induces the structural transition of WSe₂ crystalline. The electrical properties before and after adsorption of TNT molecules on the WSe₂ surface were compared; as -50 V was applied as the back gate bias, 0.02 μA was recorded in the bare state, and the drain current increased to 0.41 μA with a dropping 0.6% (w/v) TNT while maintaining the p-type behavior. Afterward, the electrical characteristics were additionally evaluated by comparing the carrier mobility, hysteresis, and on/off ratio. Consequently, the present report provides the milestone for developing ultra-sensitive sensors with rapid response and high precision.

• Journal of Industrial Convergence
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• v.21 no.12
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• pp.11-23
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• 2023

This study aims to investigate the relationship between service recovery justice, residual emotions, and customer behavior. It empirically verifies that low justice in service recovery affects residual emotions and, in turn, has an impact on customers' negative behaviors. Furthermore, this research distinguishes customer-brand relationship quality into emotional relationship quality and cognitive relationship quality and seeks to validate that the type of relationship quality may influence the extent to which the justice of recovery processes affects residual emotions. Data was collected through surveys, and hypotheses were tested using structural equation modeling. The research findings indicate that among the dimensions of service recovery justice, procedural justice and interactional justice significantly influence residual emotions. Moreover, residual emotions have a significant impact on both the intention to revisit and the intention to engage in negative word-of-mouth. In addition, the impact of distributive justice and procedural justice on residual emotions was found to be higher for cognitive relationship quality than emotional relationship quality, and the impact of interactional justice on residual emotions was found to be higher for emotional relationship quality than cognitive relationship quality.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.17 no.3
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• pp.119-133
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• 2022

The COVID-19 pandemic is rapidly changing the behavior of members of society. Typically, the strong contagious power of the virus minimizes interaction between people in the real world, and they keep interaction activities to a minimum through online activities. Recently, as people demand online activities that enhance a sense of reality, the metaverse, which strengthens the 3D technology-centered sense of presence capability, is being chosen by people. The purpose of this study is to suggest a strategic direction for the establishment of the metaverse business model of startups by presenting factors for users' use and gratification of the metaverse. In detail, this study proposes the motivation for using the metaverse by reflecting the uses and gratification theory, and suggests a method to strengthen the motivation for the metaverse by reflecting the presences provided by the metaverse plotform and individual characteristics (normtive interpersonal influence). We surveyed people over 20 years of age who experienced metaverse and obtained 314 samples. In addition, we conducted the main effect analysis using the structural equation model and the moderating effect analysis using Process 3.1. As a result of hypothesis testing, we confirmed that metaverse presence (telepresence, social presence) has a positive effect on intention to continuous use by increasing metaverse's use and satisfaction factors (information, enjoyment, social interactivity). In addition, we found that individuals' normative interpersonal influence moderated the positive relationship between uses and gratification factors(enjoyment and social interactivity) intention to continuous use. Our study suggests strategies for establishing a user-centered business model for companies related to the metaverse.

• Journal of Service Research and Studies
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• v.14 no.2
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• pp.158-177
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• 2024

This paper proposes and tests a theoretical model of the relational link between a novel form of customer-perceived fairness for a reward design (distributive peer justice climate) and C2C helping intention via community identification and online C2C interaction (friend-, neighboring customer-, audience-interaction) qualities in a collective consumption context (MMORPG). To test hypotheses, we amassed survey data within a collective consumption context (massively multiplayer online role-playing games, MMORPGs). We used structural equation modeling in analyzing the survey data. The results reveal that user-perceived distributive peer justice climate for a reward design enhances their C2C helping intention via community identification and C2C interactions in MMORPG contexts. Collective consumption-type service managers should focus on promoting the user-perceived distributive peer justice climate for their reward system to enhance users' present C2C co-creation experience (community identification, C2C interaction) and future C2C co-creation behavior (helping intention). By adopting an intra-unit level distributive justice concept (customer-perceived distributive peer justice climate) to a reward design in a collective consumption context (MMORPGs), this study informed collective consumption-type service managers of the importance of its management.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.44 no.1
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• pp.109-116
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• 2024

The Rapid Hardening Composite Mat (RHCM) is a product that improves the initial strength development speed of conventional Geosynthetic Cementitious Composite Mats (GCCM). It offers the advantage of quickly securing sufficient strength in railway slopes with insufficient formation level, and provides benefits such as preventing slope erosion and inhibiting vegetation growth. In this study, an analysis of the practical applicability of RHCM in railway settings was conducted through experimentation. The on-site applicability was assessed by categorizing it into fire resistance, durability, and stability, and conducting combustibility test, ground contact pressure test, and daily displacement analyses. In the case of South Korea, where a significant portion of the territory is composed of forested areas, the prevention of slope fires is imperative. To analyze the fire resistance of RHCM, combustibility tests were conducted as an essential measure. Durability was assessed through ground contact pressure tests to analyze the deformation and potential damage of RHCM caused by the inevitable use of small to medium-sized equipment on the construction surface. Furthermore, daily displacement analysis was conducted to evaluate the structural stability by comparing and analyzing the displacement and behavior occurring during the application of RHCM with railway slope maintenance criteria. As a result of the experiments, the RHCM was analyzed to meet the criteria for heat release rate and gas toxicity. Furthermore, the ground contact pressure was observed to be consistently above 50 kPa during the curing period of 4 to 24 hours under all conditions. Additionally, the daily displacement analyzed through field site experiments ranged from -1.7 mm to 1.01 mm, confirming compliance with the criteria.

• Information Systems Review
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• v.21 no.4
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• pp.175-195
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• 2019

This study conducted both big data and netnography analysis to analyze consumer needs and behaviors of online consumer community. Big data analysis is easy to identify correlations, but causality is difficult to identify. To overcome this limitation, we used netnography analysis together. The netnography methodology is excellent for context grasping. However, there is a limit in that it is time and costly to analyze a large amount of data accumulated for a long time. Therefore, in this study, we searched for patterns of overall data through big data analysis and discovered outliers that require netnography analysis, and then performed netnography analysis only before and after outliers. As a result of analysis, the cause of the phenomenon shown through big data analysis could be explained through netnography analysis. In addition, it was able to identify the internal structural changes of the community, which are not easily revealed by big data analysis. Therefore, this study was able to effectively explain much of online consumer behavior that was difficult to understand as well as contextual semantics from the unstructured data missed by big data. The big data-netnography integrated model proposed in this study can be used as a good tool to discover new consumer needs in the online environment.

• Journal of the Korea Concrete Institute
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• v.25 no.5
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• pp.485-496
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• 2013

In recent years, frequent terror or military attacks by explosion or impact accidents have occurred. Examplary case of these attacks were World Trade Center collapse and US Department of Defense Pentagon attack on Sept. 11 of 2001. These attacks of the civil infrastructure have induced numerous casualties and property damage, which raised public concerns and anxiety of potential terrorist attacks. However, a existing design procedure for civil infrastructures do not consider a protective design for extreme loading scenario. Also, the extreme loading researches of prestressed concrete (PSC) member, which widely used for nuclear containment vessel, gas tank, bridges, and tunnel, are insufficient due to experimental limitations of loading characteristics. To protect concrete structures against extreme loading such as explosion and impact with high strain rate, understanding of the effect, characteristic, and propagation mechanism of extreme loadings on structures is needed. Therefore, in this paper, to evaluate the impact resistance capacity and its protective performance of bi-directional unbonded prestressed concrete member, impact tests were carried out on $1400mm{\times}1000mm{\times}300mm$ for reinforced concrete (RC), prestressed concrete without rebar (PS), prestressed concrete with rebar (PSR, general PSC) specimens. According to test site conditions, impact tests were performed with 14 kN impactor with drop height of 10 m, 5 m, 4 m for preliminary tests and 3.5 m for main tests. Also, in this study, the procedure, layout, and measurement system of impact tests were established. The impact resistance capacity was measured using crack patterns, damage rates, measuring value such as displacement, acceleration, and residual structural strength. The results can be used as basic research references for related research areas, which include protective design and impact numerical simulation under impact loading.

• Journal of the East Asian Society of Dietary Life
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• v.22 no.1
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• pp.133-146
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• 2012

University dining services have received less attention than commercial food services or other institutional food services. Marketing practitioners and researchers recognize the major impact that perceived value has on consumer behavior. The mediating role of value has not been verified in relation to satisfaction in university dining establishments, including Korea. This study intends to investigate the relationships among value, satisfaction and revisit intention of university dining attributes. This study also examines whether university dining service attributes dimensions influence value. Further, this study verifies the role of value as a mediator in the formation of customer satisfaction and revisit intention. Structural Equation Modeling has been applied to the collected data from students of three universities in Korea. The study resulted in that university dining attributes, such as food, menu and convenience, positively affected value of the university dining services. Further analysis with examination of indirect effects confirmed the positive impact of value on satisfaction in university dining services. This study verified the mediating role of value on satisfaction as student's satisfaction is enhanced through the elevation of value of university food services. Enhanced satisfaction via value also led to improvement in revisit intention. This study contributes to the academia by verifying the mediating role of value in the formation of customer satisfaction in a university dining context. This study also offers practical implications to the industry, such as suggestions on developing strategies for value-added products and services to the university dining establishments. This value research for university dining services is also meaningful by triggering future research on market segmentation, product differentiation and positioning policies. In the long run, improving value and satisfaction with university dining services need to be realized to enhance overall college experiences and other competitive advantages, such as student recruitment and enrollment, student academic evaluations, and university reputation.