• Industrial Engineering and Management Systems
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• 제12권2호
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• pp.74-84
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• 2013

Modern companies have been facing devastating impacts from unexpected events such as demand uncertainties, natural disasters, and terrorist attacks due to the increasing global supply chain complexity. This paper proposes a multi stage logistic network model under disruption risk. To formulate the problem practically, we consider the effect of continuity rate, which is defined as a percentage of ability of the facility to provide backup allocation to customers in the abnormal situation and affect the investments and operational costs. Then we vary the fixed charge for opening facilities and the operational cost according to the continuity rate. The operational level of the company decreases below the normal condition when disruption occurs. The backup source after the disrup-tion is recovered not only as soon as possible, but also as much as possible. This is a concept of the business continuity plan to reduce the recovery time objective such a continuity rate will affect the investments and op-erational costs. Through numerical experiments, we have shown the proposed idea is capable of designing a resilient logistic network available for business continuity management/plan.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2019년도 추계학술발표대회
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• pp.585-588
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• 2019

Predictions of Energy Consumption for Industries gain an important place in energy management and control system, as there are dynamic and seasonal changes in the demand and supply of energy. This paper presents and discusses the predictive models for energy consumption of the steel industry. Data used includes lagging and leading current reactive power, lagging and leading current power factor, carbon dioxide (tCO2) emission and load type. In the test set, four statistical models are trained and evaluated: (a) Linear regression (LR), (b) Support Vector Machine with radial kernel (SVM RBF), (c) Gradient Boosting Machine (GBM), (d) random forest (RF). Root Mean Squared Error (RMSE), Mean Absolute Error (MAE) and Mean Absolute Percentage Error (MAPE) are used to measure the prediction efficiency of regression designs. When using all the predictors, the best model RF can provide RMSE value 7.33 in the test set.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2015년도 학술발표회
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• pp.216-216
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• 2015

Frequent hydro-meteorological events caused by global climate change and human exacerbate activities, make the water resource problem more complicated. The increasing speed urbanization brings a significant impact on the city flood control and security, water supply safety, water ecological security, water environment safety and the water engineering security in China, and puts forward higher requirements to urban water integrated management, undoubtedly which become the biggest obstacle for water ecological civilization construction, thus urgent requiring an advanced methods to enhance the effectiveness of the water integrated management. The other fields of smart ideas point out a development path for water resource development. The construction demand of smart water resource is expounded in the paper, combining the philosophy of modern Internet of things with the application of cloud computing technology. The concept of smart water resource is analyzed, the connotation characteristics of smart water resource is extracted, and the general model of smart water resource is refined. Then, the frame structure of smart water resource is put forward. The connotation and the overall framework of the smart water resource represent a higher level of water resource informationization development and provide a comprehensive scientific and technological support to transform water resource management from an extensive, passive, static, branch and traditional management to a fine, active, dynamic, collaborative and modern management.

• 무역학회지
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• 제44권3호
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• pp.25-42
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• 2019

This research examined the mediation effect of Workforce Agility (WA) on the relationship between environmental uncertainty and operational performance. We manipulated the control variables that are known to be affected by employment flexibility. Employment flexibility is caused by idiosyncratic characteristics of Korean port system. The analysis was tested by Baron & Kenny's method. The result indicates that each path of the proposed model is significant. Furthermore, the mediation effect was checked with the Sobel Test. The research revealed that environment uncertainty poses an indirect effect on operational performance. Both supply/demand uncertainty and technological uncertainty affected operational performance through the mediation effect of WA. Most of the distribution centers located in Busan Newport Distripark are operated in a bimodal labor (human resource) system which includes both permanent employees (workers) and temporary employees (workers). This empirical research provides theoretical and managerial implications by suggesting ways to increase efficiency in distribution center operation through WA enhancement, and to improve the unloading labor system.

• The Journal of Asian Finance, Economics and Business
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• 제8권8호
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• pp.167-180
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• 2021

The "sharing economy" describes a type of business built on the sharing of resources - allowing customers to access goods when needed. While sharing goods has always been a common practice among friends, family, and neighbors, in recent years, the concept of sharing has moved from a community practice into a profitable business model. This study explores gaps between customers' actual usages and current policies on accommodation sharing by analyzing what needs to be done for the better establishment of sharing economy in society. The purpose of this study is to investigate perceptions of accommodation sharing by analyzing reviews and negative aspects that help resolve complaints and improve better services through policy establishment. This study investigates key attributes that influence business performance to improve citizens' decision-making for the usage of accommodation sharing. This study applies qualitative research by collecting demand- and supply-side reviews from selected registered accommodations using a random sampling procedure. This study finds that guests prefer entire house sharing with instrumental attributes related to properties. Entire house sharing of multiple dwellings shows business impacts in terms of high occupancy rate on the platform, while there are policy concerns with entire house sharing. The results provide policy and managerial implications by suggesting proper policies and considering relationships with citizens.

• The Journal of Asian Finance, Economics and Business
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• 제9권6호
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• pp.1-9
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• 2022

The study aims to determine the factors and their influence on the income from using public agricultural land of households. Public agricultural land is agricultural land, including land for growing annual crops, perennial crops, and land for aquaculture, leased by commune-level People's Committees with a lease term of not more than 5 years. Secondary data were collected for the 2017-2021 period at state agencies. Primary data were collected from a survey of 150 households renting public agricultural land. The regression model assumed that there were 28 factors belonging to 7 groups. The test results show that 25 factors affect income, and 03 factors do not. The group of COVID-19 pandemic factors has the strongest impact, followed by the groups of agricultural product market factors, land factors, capital factors, production cost factors, labor factors, and climatic factors. The impact rate of COVID-19 pandemic factors is the largest (23.00%); The impact rate of climatic factors is the smallest (6.04%). Proposals to increase income include good implementation of disease prevention and control; increasing the land lease term; accurately forecasting the supply and demand of the agricultural market; raising the level of the household head; ensuring sufficient production capital, and adapting to the climate.

• The Journal of Asian Finance, Economics and Business
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• 제9권9호
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• pp.263-269
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• 2022

The global financial crisis of 2008-2009 and the COVID-19 pandemic that started in 2019 along with the slow and unstable recovery of the global economy have raised concerns about the impact of global uncertainty on the macroeconomics of the countries. The paper used the Structural Vector Autoregression (SVAR) model to examine the impact of global uncertainty shocks on Vietnam's economy from the period 2008-2022. We found that Vietnam's output dropped following the shock of global uncertainty, the peak was in the third month, and lasted for one year. Inflation in Vietnam had a rapid downturn in the first month, peaked in the seventh month, and took a long time to cease. When the economy experienced the shock of increased global uncertainty, Vietnam's policy interest rate was adjusted downward. Additionally, we included a long-term interest rate to consider the overall impact of monetary policy into account. A decreasing trend was also found with this rate. The global uncertainty shock effects acted as the aggregate demand shocks, reducing output and inflation as the uncertainty increases and vice versa, thus monetary policy can be used to regulate Vietnam's economy to deal with negative shocks without the trade-offs between output and inflation as aggregate supply shocks.

• 국제학술발표논문집
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• The 4th International Conference on Construction Engineering and Project Management Organized by the University of New South Wales
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• pp.241-248
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• 2011

Past theories on construction price formation have been shown to be inadequate in terms of their ability to represent real-life industry practice and price formation predictability. In this paper, we develop a theoretical framework on construction price formation that integrates four theories within the domains of marketing, learning, resource management and economics. These are: (i) marketing pricing theory; (ii) experiential and organisational learning theory; (iii) resourced based theory and (iv) microeconomic theory. Utilising pricing theory from marketing, a foundation is able to be created for the procedure of construction price formation, namely: (i) identifying the objectives; (ii) assessing the tendering environment; and (iii) formation of the price. However, understanding contractors' decision making process in tender pricing as such can be attributed to theories of experiential learning and consequently organisational learning. It is argued that contractors do learn from past experience and history and are able to adapt to different market conditions. In formation of the price, neoclassical microeconomics is able to provide additional insight in terms of the supply and demand model and consideration of the market conditions. Interrelated with the microeconomic concept of scarcity, we appreciate that contractors do have limited resources that affect their tender pricing decisions and resource based theory is used to substantiate this. Integrating the various theories as a unity allows the broader reality to be visualised and add to our theoretical understanding of construction price formation.

• Nuclear Engineering and Technology
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• 제56권3호
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• pp.949-958
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• 2024

In contrast to all-time flooded small modular reactor (SMR) systems, an in-kind flooding safety system (FSS) has been proposed as a passive safety system applicable to small modular reactors (SMRs) that adopt a metal containment vessel (MCV). Under transient conditions, the FSS can provide emergency cooling to dry reactor cavities and sustain long-term coolability using re-acquired evaporated steam in the reactor building on demand. When designing an FSS, the effect of the flooding flow area is vital as it affects the overall accident sequence and safety. Therefore, in this study, a MELCOR model of a reference SMR is developed and numerical analysis is performed under postulated accident scenarios. Without flooding, the MCV pressure of the reactor module exceeds the design pressure before core damage. To prevent core damage, an emergency flooding strategy is devised using various flow path parameters and requirements to ensure an adequate emergency coolant supply before the core damage is investigated. The results indicate that a flow area exceeding 0.02 m2 is required in the FSS to prevent MCV overpressure and core damage. This study is the first to report a strategic analysis for appropriately sizing an FSS flooding valve applicable to innovative SMRs.

• 한국산학기술학회논문지
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• 제21권4호
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• pp.538-545
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• 2020

한미 FTA 체결 이후 미국산 오렌지의 지속적인 수입증가에 따른 국내 감귤산업 파급영향에 대한 관심이 높다. 이 연구는 한미 FTA 발효 이후 2012-2017년 동안의 감귤산업의 변화를 계측하고, 한미 FTA 도입이 감귤산업에 미치는 사후 영향을 평가하였다. 이 연구는 분석을 위해 감귤류를 노지감귤, 하우스감귤, 만감류 부문으로 구분하고, 각 부문별 수급균형모형을 구축하여 시뮬레이션 분석에 이용하였다. 각 부문내 주요 방정식들은 응용계량경제학 방법을 이용하여 추정하고, 각 부문별 수급구조모형은 동태축차적 시뮬레이션모형으로 구축하여 2012-2017년 동안에 대해 연차별로 정책 시뮬레이션이 가능하도록 하였다. 각 모형은 작물연도를 기준으로 구축되었고, 해당 시기에 수입되는 오렌지, 체리 등에 수입산 대체가능 작물에 대한 효과를 고려할 수 있도록 설계되었다. 시뮬레이션 분석에 앞서 각 부문별 모형에 대한 예측력을 RMSPE, MAPE, Theil의 불균등계수 등을 기준으로 검토하였다. MAPE 기준으로 노지감귤, 하우스감귤, 만감류의 재배면적 1-7%, 생산량 5-9%, 소비량 5-10%, 경락가격 5-10% 내외의 오차율을 보여, 각 부문별 모형의 주요 변수에 대한 추정치들의 예측력이 전반적으로 양호한 수준으로 나타났다. 예측력 검토결과를 바탕으로 시뮬레이션 분석을 실시한 결과, 한미 FTA 발효 이후 2012-2017년 연평균 조수입(실질)이 노지감귤 23.9억 원, 하우스감귤 30.1억원, 만감류 151.1억 원 감소한 것으로 나타났다. 또한 이 논문은 기존에 2018년 정부부문(KREI)에서 실시한 영향평가방법 및 결과의 차이점을 비교 검토하고 해석시 유의사항 및 정책적 함의를 제안하고 있다.