• Nuclear Engineering and Technology
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• v.54 no.8
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• pp.2852-2858
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• 2022

A proton therapy facility is under development at Huazhong University of Science and Technology (HUST). To meet the need for fast energy changes during treatments, a beamline control system (BCS) has been designed and implemented. The BCS coordinates and controls various beamline devices by adopting a distributed architecture divided into three layers: the client, server, and device layers. Among these, the design of the server layer is the key to realize fast energy changes. The server layer adopts the submodule programming paradigm and optimizes the data interface among modules, allowing the main workflow to be separated from the device workflow and data. Furthermore, this layer uses asynchronous, multithreaded, and thread-locking methods to improve the system's ability to operation efficiently and securely. Notably, to evaluate the changing energy status over time, a dynamic node update method is adopted, which can dynamically adjust the update frequency of variable nodes. This method not only meets the demand for fast updates on energy changes but also reduces the server's communication load in the steady state. This method is tested on a virtual platform, and the results are as expected.

• The Journal of the Convergence on Culture Technology
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• v.8 no.4
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• pp.347-353
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• 2022

In the restaurant industry, start-ups are active due to high demand from consumers and low entry barriers. However, the restaurant industry has a high closure rate, and in the case of franchises, there is a large deviation in sales within the same brand. Thus, research is needed to prevent the closure of food franchises. Therefore, this study examines the factors affecting franchise sales and uses machine learning techniques to predict the success and failure of franchises. Various factors that affect franchise sales are extracted by using Point of Sale (PoS) data of food franchise and public data in Gangnam-gu, Seoul. And for more valid variable selection, multicollinearity is removed by using Variance Inflation Factor (VIF). Finally, classification models are used to predict the success and failure of food franchise stores. Through this method, we propose success and failure prediction model for food franchise stores with the accuracy of 0.92.

• Journal of Navigation and Port Research
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• v.46 no.4
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• pp.385-391
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• 2022

In this study, a multivariate time series analysis was conducted to identify various variables that impact ocean freight rates in addition to supply and demand factors. First, we used the ClarkSea Index, Clarksons Average Bulker Earnings, and Clarksons Average Tanker Earnings provided by the Shipping Intelligence as substitute variables for the dependent variable, ocean freight. The following ndependent variables were selected: World Seaborne Trade, World Fleet, Brent Crude Oil Price, World GDP Growth Rate, Industrial Production (IP OECD) Growth Rate, Interest Rate (US$ LIBOR 6 Months), and Inflation (CP I OECD) through previous studies. The time series data comprise annual data (1992-2020), and a regression analysis was conducted. Results of the regression analysis show that the World Seaborne Trade and Brent Crude Oil P rice impacted the ClarkSea Index. Only the World Seaborne Dry Bulk Trade impacted the Clarksons Average Bulker Earnings, World Seaborne Oil Trade, Brent Crude Oil Price, IP, and CP I on the Clarksons Average Tanker Earnings.

• Journal of The Korean Society of Integrative Medicine
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• v.10 no.3
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• pp.173-184
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• 2022

Purpose : The purpose of this study was two-fold: to identify the effect of dental hygienist's self-determination motivation on their job engagement and to analyze the moderating effect of compensation satisfaction that affect the relevance. Methods : Data were collected using a structured self-report questionnaire administered to 260 dental hygienists working in dental hospitals and clinics in Busan, South Korea. These were analyzed using IBM SPSS Statistics version 26.0 and SPSS Process Macro 3.5. A frequency analysis, including the respondents' general characteristics, frequency, percentages, and standard deviations, was performed. A regression analysis was also performed using SPSS Process Macro to verify the moderating effect of compensation satisfaction in the effect of self-determination motivation on job engagement. Results : The self-determination motivation of the dental hygienists had a statistically significant positive effect on their job engagement, which was the dependent variable. Higher intangible compensation satisfaction levels led to a stronger effect of intrinsic motivation but a weaker effect of extrinsic motivation on job engagement. Moreover, higher tangible compensation satisfaction levels strengthened the effect of intrinsic motivation on job engagement. Conclusion : Recently, the demand for oral health care has been increasing, Competition in the dental medical service market warrants, high-quality dental services based on accurate diagnosis and treatment. In this context, dental hygienists' job engagement must be improved. For this purpose, increasing the satisfaction of dental hygienists with self-determination motivation and appropriate compensation is effective. In addition, attention must be paid to the moderating effect of compensation satisfaction on the relationship between intrinsic motivation and job engagement. On the basis of the implications of this study, the results can be used as basic data for improving dental hygienists' welfare system and manpower management.

• Asia-Pacific Journal of Business
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• v.13 no.2
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• pp.39-50
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• 2022

Purpose - The purpose of this study is to examine how Korea's macroeconomic factors, such as GDP, CPI, Export, Import, Unemployment rate and USD/KRW exchange rate, are affected by the oil price shocks. Design/methodology/approach - This study used monthly and quarterly time-series data of each variable for the period 1983 to 2022, consisting of two sub-periods, to employ Granger causality test and GARCH method in order to identify the role of the oil price movement in macroeconomic factors in Korea. Findings - Korea's currency rate to the US dollar is negatively correlated with the price change of crude oil while the GDP change is positively correlated with the price change of crude oil with strong relationship between Export and Import in particular. The exchange rate and GDP growth are believed to be not correlated with the oil price change for the pre-GFC period. According to the Granger causality test, the price change in crude oil has a causal impact on CPI, Export and Import while other factors are relatively slightly affected. Transmission effect from the oil price to Export is found and there also exists volatility spillover from oil price to economic variables under examination. Comparing two sub-periods, CPI and Export volatility responds negatively to shocks in the oil price for the pre-GFC period while volatility of CPI and Unemployment reacts positively to the oil price shocks for the post-GFC period. Research implications or Originality - The findings of this study could be helpful for both domestic and international investors to build their portfolio for the risk management since rising WTI price can be interpreted as a result of global economic growth and ensuing increase in the worldwide demand of the crude oil. Consequently, the national output is expected to increase and the currency is also expected to be strong in the long run.

• Advances in Computational Design
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• v.8 no.1
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• pp.13-36
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• 2023

The Puebla-Morelos Earthquake (Mw 7.1) occurred in Mexico in 2017 causing 44 buildings to collapse in Mexico City. This work evaluates the non-linear response of a 6-story reinforced concrete (RC) frame prototype model with masonry infill walls on upper floors. The prototype model was designed using provisions prescribed before 1985 and was subjected to seismic excitations recorded during the earthquakes of 1985 and 2017 in different places in Mexico City. The building response was assessed through a damage index (DI) that considers low-cycle fatigue of the steel reinforcement in columns of the first floor, where the steel was modeled including buckling as was observed in cases after the 2017 earthquake. Isocurves were generated with 72 seismic records in Mexico City representing the level of iso-demand on the structure. These isocurves were compared with the location of 16 collapsed (first-floor column failure) building cases consistent with the prototype model. The isocurves for a value greater than 1 demarcate the location where fatigue failure was expected, which is consistent with the location of 2 of the 16 cases studied. However, a slight increase in axial load (5%) or decrease in column cross-section (5%) had a significant detrimental effect on the cumulated damage, increasing the intensity of the isocurves and achieving congruence with 9 of the 16 cases, and having the other 7 cases less than 2 km away. Including column special detailing (tight stirrup spacing and confined concrete) was the variable with the greatest impact to control the cumulated damage, which was consistent with the absence of severe damage in buildings built in the 70s and 80s.

• Journal of Distribution Science
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• v.21 no.7
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• pp.51-63
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• 2023

Housing is not only a basic requirement, but also a method to maintain stability and improve living. In the period of rapid social development which has a significant impact on the aging population, the housing issue is an impediment to Gen Y in Asia. Therefore, solving the housing conundrum is the most effective solution to other social problems. Purpose: This research is conducted to investigate factors influencing housing-option decisions of Gen Y and proposes recommendations to them as well as Governments and the real estate investors. Research design, data, and methodology: The Theory of Planned Behavior was employed with the expanded variables (Financial status, Location, Public services and Government incentives) based on literature review. Results: With 445 valid responses, almost all proposed hypotheses are accepted, which supports the positive interrelationship among variables. In the stage of data processing, we have determined the influence of each factor to the dependent variable "Actual Behavior", thereby helping real estate investors understand their desires, as well as improve the ability to meet customer needs. Conclusion: This is the basis to determine the influence of these factors, thereby providing recommendations to customers and what is more, giving real estate enterprises an insight of customers' demand in order to improve product quality and optimize the benefits of each party.

• Journal of Korea Trade
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• v.27 no.2
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• pp.47-60
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• 2023

Purpose - This paper assesses the trade potential and efficiency of Korea and China in the aquatic products trade. Trade efficiency and potential are the main factors that affect the growth of a country's trade. In this study, a time-varying stochastic frontier trade gravity model was constructed to analyze the trade potential and efficiency between Korea and China. By integrating the results of trade theory and empirical analysis, measures and suggestions were proposed to encourage the release of trade potential of fish exports between Korea and China. Design/methodology - In this paper, GDP per capita instead of economic size was chosen as an explanatory variable, and population size and relative distance were selected as explanatory variables to measure trade potential. For trade non-efficiency terms, regional organizations, political factors, and economic factors were mainly considered, and variables such as free trade agreements, political stability, regulatory quality, government efficiency, currency freedom, investment freedom, financial freedom, and trade freedom were selected. Panel data for South Korea and 14 aquatic products trading partners (including China) from 2002 to 2020 were used in the empirical analysis. Findings - In the past 19 years, South Korea's export trade potential of aquatic products to China has never been lower than 70%. It was above 90% from 2006 to 2018, and has been at a high level for a long time. This shows that China's aquatic product market has large potential for development. Originality/value - This study examines the effectiveness and potential of South Korea's exports of aquatic items to China in a methodical and comprehensive empirical manner. The evaluation of the export trade potential of South Korea's aquatic goods to China is more precise when the effects of regional organization, political, and economic variables are taken into account in the trade non-efficiency term of the stochastic frontier gravity model. At the same time, we propose to increase the scale of South Korea's aquatic products trade from the perspective of China's demand. This issue of trade studies is underexplored both empirically and in theory, although the issue has long been important to Korean and world trade.

• Earthquakes and Structures
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• v.25 no.2
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• pp.125-134
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• 2023

In the present work, a new global damage index is proposed for the seismic performance and failure analysis of concrete gravity dams. Unlike the existing indices of concrete structures, this index doesn't need scaling with an ultimate or an upper value. For this purpose, the Beni-Haroun dam in north-eastern Algeria, is considered as a case study, for which an average seismic capacity curve is first evaluated by performing several incremental dynamic analyses. The seismic performance point of the dam is then determined using the N2 method, considering multiple modes and taking into account the stiffness degradation. The seismic demand is obtained from the design spectrum of the Algerian seismic regulations. A series of recorded and artificial accelerograms are used as dynamic loads to evaluate the nonlinear responses of the dam. The nonlinear behaviour of the concrete mass is modelled by using continuum damage mechanics, where material damage is represented by a scalar field damage variable. This modelling, which is suitable for cyclic loading, uses only a single damage parameter to describe the stiffness degradation of the concrete. The hydrodynamic and the sediment pressures are included in the analyses. The obtained results show that the proposed damage index faithfully describes the successive brittle failures of the dam which increase with increasing applied ground accelerations. It is found that minor damage can occur for ground accelerations less than 0.3 g, and complete failure can be caused by accelerations greater than 0.45 g.

• Transactions of Materials Processing
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• v.33 no.2
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• pp.103-111
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• 2024

With the increasing global interest in carbon neutrality, the automotive industry is also transitioning to the production of eco-friendly cars, specifically electric vehicles. In order to achieve comparable driving distances to internal combustion engine vehicles, the application of high-capacity battery packs has led to an increase in vehicle weight. To achieve light-weighting and durability requirements of automotive components simultaneously, there is a demand for research on the application of Ultra-High Strength Steel (UHSS). However, when manufacturing chassis components using UHSS, there are challenges related to fracture defects due to lower elongation compared to regular steel sheets, as well as spring-back issues caused by high tensile strength. In this study, a simulated specimen that is not affected by the property changes of four materials was designed to improve formability of the rear cross member, which is the most challenging automotive chassis component. The influence and correlation of material-specific variables were analyzed through finite element analysis (FEA) for each material with tensile strength of 440, 590, 780, and 980 MPa grades, resulting in the development of a predictive equation. To validate the equation, the simulated specimens of 980 MPa grade were produced from the test molds. Then the reliability of the FEA and predictive equation was verified with measured specimen data using a 3D scanner. The results of this study can be proposed to improve the formability of UHSS chassis components in future researches.