• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.28 no.5
• /
• pp.171-177
• /
• 2016

Plate heat exchangers have been widely used in various fields because of their high heat transfer coefficients, small area of installation, and ease of maintenance compared to other heat exchangers. However, when plate heat exchanger is used for a long time, leak can occur due to inner crack. Therefore, it is important to understand the inner flow characteristics in plate heat exchangers. In this study, the inner flow characteristics and flow rate of plate heat exchanger were evaluated using various flow directions, pin-hole sizes, and Reynolds numbers. In downflow, initially most water flowed to the opposite of the inlet due to distribution region. Then it gradually had a uniform distribution due to chevron configuration. In upflow, it had a uniform flow consistently due to the dominant gravity effect. As the Reynolds number increased, the leak rate was decreased due to the inertia effect regardless of the flow direction.

• Progress in Superconductivity
• /
• v.5 no.2
• /
• pp.149-152
• /
• 2004

The design and the fabrication of a 1 MVA single-phase HTS transformer are presented in this paper, The rated voltages are 22.9 ㎸ for primary and 6.6 ㎸ for secondary, and the rated currents are 44 A and 152 A respectively. The transformer has HTS double pancake type windings. This type of winding has many advantages such as ease of fabrication and maintenance, good distribution of surge voltage and insulation of windings. Single HTS wire was used for primary winding and four HTS parallel wires were used for secondary winding. These windings are arranged reciprocally with the shell type iron core. An FRP cryostat with room temperature bore was fabricated to isolate the iron core from the coolant. The winding will be cooled down to 65 K with sub-cooled liquid nitrogen using a GM-cryocooler. The sub-cooled liquid nitrogen has advantages of good insulation because of no bubbles as well as increased current capacity of HTS wire.

• The Journal of Industrial Distribution & Business
• /
• v.9 no.1
• /
• pp.51-65
• /
• 2018

Purpose - This paper aims to identify factors that influence the users' word-of-mouth intention (WOMI) regarding mobile apps, focussing on the impacts of technology acceptance model (TAM) and social network theory. Research design, data and methodology - Based on TAM, this study integrates social network theory into the research model. The 317 sets of data collected in a survey were tested against the model using SmartPLS. Results - Our findings suggest the following: 1) Personal innovativeness positively influences perceived usefulness (PU), perceived ease of use (PEU) and perceived enjoyment (PE); 2) PEU affects PU and PE; 3) Both PU and Satisfaction are directly correlated with WOMI. Although PEU and PE has no direct impact on WOMI, they may indirectly affect WOMI via Satisfaction, as PU, PEU and PE all positively influence satisfaction; 4) Network density and network centrality both play a mediating role in the relation between PEU and WOMI. Referral Reward Program have a positive moderating effect on the relation between PU and WOMI. Conclusions - The findings of this study illustrate the traits of Apps that can promote users' WOMI, as well as the characteristics of people who are more likely to participate in the word-of-mouth process. The findings provide a theoretical basis for app developers to make word-of-mouth a marketing strategy.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.25 no.8
• /
• pp.450-456
• /
• 2013

The composite electric oven is one of the fixing utensil, various functions are required. Steam generating function, which is one of its functions, and allows various food cooking. The location of the outlet of the steam generator is designed around ease of installation, consideration of internal fluid is not. Distribution of the steam can not be non-uniformly. Accordingly, cooking time becomes longer, the energy consumption increases. As a result of the analysis, it was confirmed stagnation phenomenon of the internal flow through the interpretation of the calculations for the position of the outlet of the steam generator existing. Further, by computing the analysis of various locations of the outlet of the steam generator, we investigated the distribution and characteristics of the internal flow.

• Journal of Soil and Groundwater Environment
• /
• v.25 no.4
• /
• pp.87-97
• /
• 2020

In this study, the applicability of the geostatistical evolution strategy as an inverse analysis method of estimating hydraulic properties of small-scale basin was tested. The geostatistical evolution strategy is a type of data assimilation method that can effectively estimate aquifer hydraulic conductivity by combining a global optimization model of the evolution strategy and a local optimization model of the ensemble Kalman filtering. In the applicability test, the geometry, hydraulic boundary conditions, and the distribution of groundwater monitoring wells of Hanlim-Eup were employed. On the other hand, a synthetic hydraulic conductivity distribution was generated and used as the reference property for ease of estimation quality assessment. In the estimations, two different cases were tested where, in Case I, both groundwater levels and hydraulic conductivity measurements were assumed to be available, and only the groundwater levels were available, in Case II. In both cases, the reference and estimated hydraulic conductivity fields were found to show reasonable similarity, even though the prior information for estimation was not accurate. The ability to estimate hydraulic conductivity without accurate prior information suggests that this method can be used effectively to estimate mathematical properties in real-world cases, many of which little prior information is available for the aquifer conditions.

• The Journal of Industrial Distribution & Business
• /
• v.13 no.8
• /
• pp.29-50
• /
• 2022

Purpose - This study aims to investigate factors affecting Chatbot service acceptance attitude. For wide use of Chatbot service, firms need to find barriers or obstacles for customers, if any, not to use Chatbot service. Research design, data, and methodology - We apply value-based accept model to investigate the quality of Chatbot, to verify the meaning of service value of Chatbot and to find the relationship among variables. To test hypotheses, we conducted survey. We collected 300 questionnaires. SPSS version 2.0 is used. Regression analysis, moderating effect test is conducted. Results - 4 Qualities of Chatbot, Ease of use, Usefulness, Enjoyment, Interaction are affecting acceptance attitude, and 5 service values, only interaction does not affect emotion. Trust, Specialty, Necessity, Social, Emotion moderating Chatbot service to accepting attitude. Regarding moderating effects by personal characteristics and personal tendency, innovation resistance, innovativeness, and social effects are turned to have influence while regulatory focus, construal level does not have moderating force. Also, the auxiliary service like Chatbot service affects customers' evaluation on the main service quality. Conclusions - Service firms adopt Chatbot service for various purposes. The results imply that customers are generally recognize the merits of Chatbot, but there are some barriers such as innovation resistance characteristic especially uncomfortable.

• Journal of the Korean Geotechnical Society
• /
• v.25 no.12
• /
• pp.131-142
• /
• 2009

Geosynthetic reinforced soil walls are well recognized alternatives to conventional retaining walls due to many advantages in terms of ease of construction, economy, and aesthetics, among others. In recent years, the use of back-to-back (BTB) geosynthetic reinforced soil walls has been increasing for roadway and railway construction. However, there are insufficient studies concerning the behavior of BTB type geosynthetic reinforced soil walls. In this study a series of finite element analysis were performed for BTB walls with various wall geometry and reinforcement distribution. The results were then analyzed to relate the wall geometry and reinforcement distribution and the performance of BTB walls. Optimum reinforcement pattern was also investigated.

• The Journal of Industrial Distribution & Business
• /
• v.14 no.12
• /
• pp.11-21
• /
• 2023

Purpose: This study aims to investigate the impact of mobile shopping app components on shopping flow and the continuous usage intention of the shopping apps in the rapidly growing mobile market facilitated by advancements in the mobile environment. Research Methodology: A survey was conducted, targeting users aged 20 and older with experience in using mobile shopping apps. The responses of 456 participants were analyzed through frequency analysis, exploratory factor analysis, reliability analysis, confirmatory factor analysis, and structural equation modeling. Results: The study found that within the components of mobile shopping apps, enjoyment significantly impacted both shopping flow and the continuous usage intention of shopping apps. The diversity of product assortment had a significant effect only on shopping flow. The usefulness and ease of use influenced on the intention to continue using shopping apps. Conclusions: Based on the findings, it is recommended that shopping app operators try to identify essential components for stimulating user interest and engagement when developing or modifying apps. Additionally, a diverse range of products enhances the shopping experience and drives spontaneous purchases. Furthermore, providing an easy interface and minimizing the effort required, this experience can enhance user perception of its value and sustain consumers' continuous usage intention of the shopping app.

• Journal of Distribution Science
• /
• v.21 no.11
• /
• pp.103-111
• /
• 2023

Purpose: This research aims to study the selection attributes influencing the purchasing decisions of the MZ generation in online luxury stores and explores the moderating effects of consumer value. The research aims to validate the impact of reasonable pricing, brand reliability, product variety, comprehensive product information, and user-friendly interfaces on customers' decision to purchase products from online luxury stores. Research design, data and methodology: A survey was conducted with 101 participants, and data analysis included exploratory and confirmatory factor analysis, as well as covariance structure model analysis. Results: The findings reveal that brand trust, product variety, and information sufficiency significantly influence brand affect, which in turn influences purchase intention. Additionally, the study identifies that consumers prioritizing hedonic value are more influenced by brand trust and information, while those prioritizing utilitarian value are more responsive to factors like reasonable price, product variety, and ease of use. Conclusions: The study provides insights into the preferences and behaviors of the MZ generation, highlighting their digital proficiency, mobile-centric lifestyle, desire for product variety, price-consciousness, social media influence, and the availability of personalized shopping experiences as factors contributing to their preference for online luxury stores. These findings contribute to understanding consumer behavior and decision-making processes in the context of online luxury shopping.

• Journal of Distribution Science
• /
• v.22 no.9
• /
• pp.27-38
• /
• 2024

Purpose: Sustainable economic growth is a top priority for any country, and inflation is crucial in determining future economic circumstances. Few research exists regarding the impacts of risk management practices on performance outcomes in the supply chain with the mediating role of inflation rate. Hence, this study investigates the important role of risk management practices in the context of high inflation rate. Research design, data and methodology: The PLS-SEM model is applied to identify the effects of risk management practices on operational performance and supply chain performance. The author distributed online and offline surveys to administrators at various businesses. After applying the filtration criteria, 309 responses were retained for further data analysis. Results: This research demonstrates that risk management practice is critical and adds to supply chain performance success. Managers should enhance all risk management procedures to regulate and manage hazards in the supply chain. This allows managers to anticipate and identify potential threats with ease, particularly in high inflation rate situation. Conclusions: The outcomes of this study demonstrate how fully implemented risk management practices can improve operational performance and supply chain performance, as well as control the impact of inflation rate.