In this study, numerical analysis was performed for the purpose of analyzing the flow characteristics and performance according to the change in the inflow hydrogen temperature and differential pressure of the receptacle of the hydrogen charging system. The pressure distribution and turbulent kinetic energy in the filter area were analyzed by changing the outlet pressure condition under the inlet hydrogen temperature condition, and the flow velocity change at the outlet was compared and analyzed. As a result of the analysis, as the differential pressure decreased, the flow rate at the outlet of the receptacle decreased by up to about 70% at the 2.86 MPa condition compared to the 1.86 MPa condition, and the mass flow rate decreased by about 56.5% at the maximum. It was found that the standard CV performance was not satisfied when the differential pressure at the inlet and outlet was 1.12 MPa or less under the 363K temperature condition.

VRFB에 사용되는 막의 수송 능력은 배터리 성능에 필수적인 요소이다. 탁월한 배터리 성능을 위해서는 높은 양 성자 전도도와 낮은 바나듐 이온 투과도가 달성되어야 한다. 하지만 양성자 전도도와 바나듐 이온 투과도 사이에는 상충관계 가 존재한다. 따라서 이 상충관계를 해결하는 것이 VRFB의 발전에 필수적이다. 또한 높은 쿨롱 효율, 전압 효율 및 에너지 효율을 유지하는 것이 고성능 VRFB를 위해 필수적이다. 최근 복합막과 SPEEK 막을 중심으로 나피온 막의 기존 한계를 극 복하기 위한 다양한 시도가 이루어지고 있다. VRFB은 이 논문에서 검토하는 복합막에서 충전식 배터리의 필수 등급이다.

This study focused on how retail tech promotes differentiated customer experiences in offline fashion stores. The purpose of this study is to determine the effects of the characteristics of fashion retail tech stores on consumers’ flow and satisfaction. We surveyed Koreans aged 10 to 50 who had experienced offline fashion retail tech stores. The survey was conducted from April 28, 2023, to May 21, 2023. The total number of survey respondents was 200. The quantitative data collected through questionnaires was analyzed using SPSS 25.0. To reveal the effects of fashion retail tech store characteristics on consumer’s flow and satisfaction, frequency analysis, we conducted frequency analysis, factor analysis, reliability analysis, correlation analysis, and regression analysis. The results of this study, figured out that fashion retail tech store’s characteristics, including playfulness, efficiency, interaction, and information provision, have a significant impact on behavior flow, emotional flow, and satisfaction. As a result of analyzing the influence of consumers’ flow led to satisfaction, it was confirmed that emotional flow positively influenced satisfaction, but behavioral flow had no meaningful effect on satisfaction. The results of our study can be used to make a successful marketing strategy and can serve as foundational data for consumer research on retail-tech-applied offline fashion stores.

A spiral flow path was applied to solve the problem of the existing straight flow path in the leveling shaft, a key component of the self-levelizer that can maintain the height according to the change in payload in EV, SUV. In this study, flow analysis was performed to check the velocity, pressure drop, and flow direction of oil according to the main operating conditions of the leveling shaft with a spiral flow path. As a result of the study, a leveling shaft with a spiral flow path is likely to improve fluid properties around the orifice and inlet valve under compression conditions, and it is judged to have a development application effect.

소음공해는 인간과 해양환경에 악영향을 끼치며, 선박과 해양구조물에서 발생하는 유동소음을 예측을 통해 소음에 대한 안전 성을 평가하고 해양환경을 보존할 수 있다. 기존 수중구조 유동소음 해석기법은 전산유체역학과 FW-H음향상사식을 이용한 하이브리드법 기반이다. FW-H는 무한공간에서의 음향전파를 가정하여 소음해석을 수행하기 때문에 음파의 반사와 산란, 회절의 영향이 나타나는 근접 장 해석이 제한적이다. 반면 격자볼츠만기법 기반의 직접법 유동소음해석을 수행하면 근접장 음향효과를 소음해석에 반영할 수 있다. 직 접법 해석은 유동과 소음이 연성된 해석이 수행되고 구조경계에서의 반사와 회절, 유동에 의한 매질 불균일성에 따른 산란효과가 반영된 다. 그간 격자볼츠만기법이 수중조건에서 수치적으로 불안정하여 수중환경에 적용이 불가능했다. 하지만 수중환경에서 사용할 수 있는 DM-TS 격자볼츠만기법 충돌연산자가 개발되어 수중으로 확장이 가능해졌다. 본 연구에서는 파이프내 원형구멍에 대하여 격자볼츠만기 법 해석을 수행해 수중 유동소음해석이 가능함을 보였다. 격자볼츠만기법 해석을 통해 도출한 유동과 소음을 각각 실험과 비교하여 해석 의 신뢰도를 확보하였다. 파이프내 유동소음에 의한 주요 압력 피크가 해석에 반영되었으며 이를 통해 격자볼츠만기법을 이용한 근접장 유동소음해석이 가능함을 확인했다.

As interactive marketing devices that serve as proximity-marketing tools, AI-powered voice assistants (VA) provide consumers with highly innovative convenience, which in turn fosters consumer–brand relationships (Wang, 2021). This research aims to explore the role of AI-powered VAs as a positive technology that offers consumers a sense of positive experiences, thus contributing to building a consumer-brand relationship. Based on the positive technology paradigm and transformation of flow strategy, this research conducted a 2 (locus of agency: high, machine-centric vs. low, human-centric) by 2 (brand image and voice congruency effect: incongruent vs. congruent) between-subjects experimental design. Then, ANOVA and structural equation modeling (SEM) analysis were conducted to explain how perceived control, flow, and happiness induced by the interaction with brands’ AI-powered VAs lead to the formation of brand loyalty under the moderating influences of brand image and VA’s voice congruency. A total of 316 participants were recruited via Prolific. The ANOVA analysis highlights the importance of user-centric agency, as people tend to desire to control their environment (White, 1959). Further, the results suggest that the congruency between brand image and VAs also leads people to positive reactions, as it improves their comfort and control (Rodero, Larrea, & Vázquez, 2013). SEM analysis results found that perceived control was a crucial factor that led participants to flow experience (Ghani et al., 1991). Further, this study found that perceived control could lead to a much broader aspect, such as an increase in happiness. Therefore, the overall study findings support the potential of AI-powered VAs as a positive technology. This research contributes to human-machine interaction, positive technology paradigm, and VA literature. In addition, this study provides beneficial insights for marketers and app developers.

The purpose of flow analysis is to develop a simple CFD analysis model to develop a heat transfer analysis model including transient heat transfer characteristics, especially phase change, of thin film evaporators. The simple analytical model focuses on the evaporation phase change. To reduce the computational cost, the shape was simplified to two dimensions, and the simulation time was set short with a focus on simulating the phase change phenomenon. In the future, based on this analysis model, we will develop an analysis model for simulating not only vaporization but also liquefaction, that is, transient distillation phenomenon, according to the shape of the thin film distillation device.

In this study, numerical modeling on the gas flow and off-gases in the low temperature carbonization furnace for carbon fiber was analyzed. The furnace was designed for testing carbonization process of carbon fibers made from various precursors. Nitrogen gas was used as a working gas and it was treated as an incompressible ideal gas. Three-dimensional computational fluid dynamics for steady state turbulent flow was used to analyze flow pattern and temperature field in the furnace. The off-gas mass fraction and cumulative emission gas of species were incorporated into the CFD analyses by using the user defined function(UDF). As a results, during the carbonization process, the emission of CO2 was the dominant among the off-gases, and tow moving made the flow in the furnace be uniform.

The following results were obtained by conducting a flow experiment. The experiment with air volume showed that the ducts with 3 shapes in the same cross-sectional area were large in the order of circular duct, square duct, and flexible duct. As a result of measuring the pressure value by duct shape to determine the cause of the difference between the flow rate and the air volume value by duct, the negative pressure was large in the order of circular duct, square duct, and flexible duct. in the countercurrent test, In the case of circular ducts, the deviation was high, In the case of Flexible ducts, the mild increase in the countercurrent is judged to be the difference in pressure and friction received by shape.

Gate valves are hydraulic components used to shut-off the water flow in water distribution systems. Gate valves may fail owing to various aspects such as leakage through seats, wearing of packing, and corrosion. Because it is considerably challenging to detect valve malfunctioning until the operator identifies a significant fault, failure of the gate valve may lead to a severe accident event associated with water distribution systems. In this study, we proposed a methodology to diagnose the faults of gate valves. To measure the pressure difference across a gate valve, two pressure transducers were installed before and after the gate valve in a pilot-scaled water distribution system. The obtained time-series pressure difference data were analyzed using a machine learning algorithm to diagnose faults. The validation of whether the flow rate of the pipeline can be predicted based on the pressure difference between the upstream and downstream sides of the valve was also performed.

Geologic disposal at deep depth is an acceptable way to dispose of high-level radioactive waste and isolate it from the biosphere. The geological repository system comprises an engineered barrier system (EBS) and the host rock. The system aims to delay radionuclide migration through groundwater flow, and also, the flow affects the saturation of the bentonite in the EBS. The thermal conductivity of bentonite is a function of saturation, so the temperature in the EBS is directly related to the flow system. High-temperature results in the two-phase flow, and the two-phase flow system also affects the flow system. Therefore, comprehending the influencing parameters on the flow system is critical to ensure the safety of the disposal system. Various studies have been performed to figure out the complex two-phase flow characteristics, and numerical simulation is considered an effective way to predict the coupled behavior. DECOVALEX (DEvelopment of COupled models and their VALidation against EXperiments) is one of the most famous international cooperating projects to develop numerical methods for thermo-hydro-mechanicalchemical interaction, and Task C in the DECOVALEX-2023 has the purpose of simulating the Fullscale Emplacement (FE) experiment at the Mont-Terri underground research laboratory. We used OGS-FLAC, a self-developed numerical simulator combining OpenGeoSys and FLAC3D, for the simulation and targeted to analyze the effecting parameters on the two-phase flow system. We focused on the parameters of bentonite, a key component of the disposal system, and analyzed the effect of compressibility and air entry pressure on the flow system. Compressibility is a parameter included in the storage term, defining the fluid storage capacity of the medium. While air entry pressure is a crucial value of the water retention curve, defining the relation between saturation and capillary pressure. From a series of sensitivity analyses, low compressibility resulted in faster flow due to low storage term, while low air entry pressure slowed flow inflow into the bentonite. Low air entry pressure means the air easily enters the medium; hence the flow rate becomes lower based on the relativity permeability definition. Based on the sensitivity analysis, we further investigate the effect of shotcrete around the tunnel and excavation damaged zone. Also, long-term analysis considering heat decay of the radioactive waste will be considered in future studies.

Since 1992, various numerical codes, such as TOUGH-FLAC and ROCMAS, have been developed and validated to dispose of Spent Nuclear Fuel (SNF) safely through a series of DEvelopment of COupled models and their VALidation against EXperiments (DECOVALEX) projects. These codes have been developed using different approaches, such as general two-phase flow and Richards’ flow which is an approximated approach neglecting gas pressure change, to implement the same multiphysics behaviors. However, the quantitative analysis for numerical results, which originated from different fundamental approaches, has not been conducted accurately. As a result, improper utilization of the approach to analyze certain conditions occurring such as dramatic gas pressure change may result in erroneous outcomes and systemic problem pertaining to TH analysis. In this study, the quantitative analysis of the two approaches, in terms of TH behavior, was conducted by comparing them with a 1D simulation of the CTF1 experiment carried out by laboratory experiment. The results calculated by different approaches show agreement in terms of TH behaviors and material properties change until 120°C. The results verify the applicability of Richards’ flow approach in a high temperature environment above the current thermal criteria, set as 100°C, and gas pressure change does not have a significant impact until 120°C. Therefore, although further studies for applicability of Richards’ flow are needed to suggest the appropriate temperature range, these quantitative analyses may contribute to the performance assessment of a compact repository using the high-temperature bentonite concept, which is currently gaining attention.

In this paper, a basic study was conducted to observe the temperature inside the tube according to the heating temperature of the tube furnace. In a tube furnace, a tube is inserted, and the air space outside the tube is heated to increase the temperature of the gas inside the tube through conduction of the tube. Tube furnaces are widely used in research to capture volatile nuclides. In this case, a volatile nuclide capturing filter is inserted inside the tube, and an appropriate temperature is required to capture it. Since the tube furnace heats the air space outside the tube to the target temperature, a difference from the temperature inside the tube occurs. In particular, if a flow of gas occurs inside the tube, a larger temperature difference may occur. In order to confirm this temperature difference, an experimental device was constructed, and basic data was produced through several experiments. The following studies were conducted to produce data. First, the temperature of the air layer of the heating unit and the temperature inside the tube were measured in real time in the absence of gas flow inside the tube. Second, the temperature of the air layer of the heating unit and the temperature inside the tube were measured in real time while air having a certain temperature was flowing inside the tube. As a result of the experiment, when there is no flow inside the tube, when the heating target temperature is low, the temperature inside the tube is significantly lower than the target temperature, and when the target temperature is high, the temperature inside the tube approaches the target temperature. It was found that when there is about 20°C air flow inside the tube, the temperature inside the tube is significantly lowered even if the heating target temperature is high. In the future, additional research on changing the temperature of the gas flowing inside the tube will be conducted, and the results of this study are expected to greatly contribute to the design of a tube furnace that captures volatile nuclides.

This study analyzed the flow inside floating seedling equipment for Scapharca subcrenata. Due to the aging society of fishing villages, it is impossible to continuously input the labor force. Therefore, it is necessary to improve efficiency. Scapharca subcrenata has high per capita consumption. It serves as an important aquatic food resource. Scapharca subcrenata culture tends to be highly dependent on the natural environment. Production of Scapharca subcrenata is difficult to predict with low stability. In the past, manpower directly installed bamboo nets in mudflats. The seedling equipment devised in this study is a floating type and can be freely moved on the sea according to the prediction of Scapharca subcrenata generation. The flow around the floating seedling equipment was analyzed by numerical analysis. The physical phenomena of the flow around the net inside the floating seedling equipment were visualized. As a result, the space between the floating seedling equipment and the bottom net and the space between the net groups showed a lower flow rate than the inlet flow rate. It is expected that the low flow rate of the floating seedling equipment will have a positive effect on the attachment of Scapharca subcrenata.

본 연구의 목적은 가상현실 체육실 수업의 실재 경험이 즐거움과 몰입을 경험할 때 스포츠 활동 참여의도에 어떤 영향을 미치는지 알아보는 것이다. 조사는 초등학교 고학년을 대상으로 총 300명을 60부 씩 표본추출하여 설문지 중 응답이 불성실한 24부를 제외하고 총 276부의 자료를 연구에 사용하였다. 본 연구에서 사용한 데이터 처리는 SPSS ver. 24.0 및 AMOS 버전. 24.0 통계프로그램을 이용하여 확증요인 분석, 빈도분석, Cronbach's α 계수계산, 상관분석, 구조방정식모형분석을 실시하였다. 이러한 과정을 통 해 다음과 같은 결과를 도출하였다. 첫째, 가상현실 체육실 수업의 실재 체험은 즐거움에 정(+)의 영향을 미쳤다. 둘째, 가상현실 체육실 수업에서 즐거움과 몰입의 관계는 정(+)의 영향을 미쳤다. 셋째, 가상현실 체육실 수업의 즐거움은 체육활동 참여의도에 정(+)의 영향을 미쳤다. 넷째, 가상현실 체육실에 참가한 학 생들의 수업몰입도는 향후 체육활동 참여의도에 정(+)의 영향을 미쳤다.