• Journal of the Korea Institute of Building Construction
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• v.20 no.2
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• pp.137-145
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• 2020

The recent bridge construction projects demand thorough and systematic safety and risk management, due to the increase of risk factors following the introduction of new and complex construction methods and technologies. Among many types of damages that can occur in bridge construction projects, the damages to third parties who are not directly related to the existing property of the contractor construction project can also bring about critical loss in the project in order to compensate the damages. Therefore, risks that could be caused by the loss occurred to indemnify the third party damages should be clearly analyzed, although there are not subsequent amount of studies focusing on the issue. Based on the past record of insurance payment from domestic insurance companies for bridge construction projects, this study aimed to analyze the risk factors of bridge construction for loss caused to compensate the third-party damages happened in actual bridge construction projects and to develop a quantified and numerical predictive loss model. In order to develop the model, the loss ratio was selected as the dependent variable; and among many analyzed independent variables, the superstructure, foundation, flood, and ranking of contractors were the four significant risk factor variables that affect the loss ratio. The results produced can be used as an essential guidance for balanced risk assessment, supplementing the existing analysis on material losses in bridge construction projects by taking into account the third-party damage and losses.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.39
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• pp.59-85
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• 2008

An independent bank guarantee(aka an independent guarantee) is provided as an security on a principal obligor's performance of his obligation, and a guarantor should pay the guaranteed amount only upon a beneficiary's written demand. A standby letter of credit has been used in the United States, since it was construed that a bank should not issue a guarantee. There was wide misunderstanding that a standby letter of credit differs from an independent bank guarantee. However, a standby letter of credit is the same security as an independent bank guarantee, and in international business a standby letter of credit is not differentiated from a independent bank guarantee. An independent bank guarantee are independent from the underlying contract, unconditional, and irrevocable. And a guarantor should pay upon written demand without proving a principal obligor breaches the underlying contract. These features of an independent bank guarantee has been abused in international transactions. Thus it has been proposed that some exceptions to the features of an independent bank guarantee should be allowed. United Nations Convention on Independent Guarantees and Standby Letter of Credit(1995) stipulates some exceptions to payment obligation. Export bond insurance, a part of export insurances, operated by the Korea Export Insurance Corporation under the Export Insurance Act, is used as a security for unfair calling by a beneficiary under an independent bank guarantee. Most of the export subsides by the government are prohibited under WTO's Agreement on Subsidies and Countervailing Measures. However, as export insurance is allowed under the WTO, it operates a significant role in enhancing the export. In the event that export bond insurance is provided for a guarantor, an obligor who is subject to recourse by a guarantor, can be exempt from the recourse in case of unfair calling. The Korea Export Insurance Corporation, an insurer, bears unfair calling risk by a beneficiary. Generally it is understood that a demand shall be made before the expiry of an independent bank guarantee. However this is not absolutely true, it shall be decided by URDG, ISP98, the governing law.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.21 no.4
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• pp.77-89
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• 2013

The purpose of this study is to anticipate the air travel demands over the period of 164 months, from January 1997 to August 2010 using ARIMA-Intervention modeling on the selected sample data. The sample data is composed of the number of the passengers who in the domestic route for Jeju route. In the analysis work of this study, the past events which are assumed to have affected the demands for the air travel routes to Jeju in different periods were used as the intervention variables. The impacts of such variables were reflected in the presupposed demand. The intervention variables used in this study are, respectively, the World Cup event in 2002 (from May to June), 2003 SARS outbreak (from April to May), Tsunami in January 2005, and the influenza outbreak from October to December 2009. The result of the above mentioned analysis revealed that the negative intervention events, like a global outbreak of an epidemic did have negative impact on the air travel demands in a risk aversion by the users of the aviation services. However, in case of the negative intervention events in limited area, where there are possible substituting destinations for the tourists, the impact was positive in terms of the air travel demands for substituting destinations due to the rational expectation of the users as they searched for other options. Also in this study, it was discovered that there is not a binding correlation between a nation wide mega-event, such as the World Cup games in 2002, and the increased air travel demands over a short-term period.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.220-220
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• 2015

Water, energy, and food security already became a risk that threatens people around the world. Increasing of resources demand, rapid urbanization, decreasing of natural resources and climate change are four major problems inducing resources' scarcity. Indeed, water, energy, and food are interconnected each other thus cannot be analyzed separately. That is, for simple example, energy needs water as source for hydropower plant, water needs energy for distribution, and food needs water and energy for production, which is defined as W-E-F nexus. Due to their complicated linkage, it needs a computer model to simulate and analyze the nexus. Development of a computer simulation model using system dynamics approach makes this linkage possible to be visualized and quantified. System dynamics can be defined as an approach to learn the feedback connections of all elements in a complex system, which mean, every element's interaction is simulated simultaneously. Present W-E-F nexus models do not calculate and simulate the element's interaction simultaneously. Existing models only calculate the amount of water and energy resources that needed to provide food, water, or energy without any interaction from the product to resources. The new proposed model tries to cope these lacks by adding the interactions, climate change effect, and government policy to optimize the best options to maintain the resources sustainability. On this first phase of development, the model is developed only to learn and analyze the interaction between elements based on scenario of fulfilling the increasing of resources demand, due to population growth. The model is developed using the Vensim, well-known system dynamics model software. The results are amount of total water, energy, and food demand and production for a certain time period and it is evaluated to determine the sustainability of resources.

• Journal of Agricultural Extension & Community Development
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• v.29 no.3
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• pp.131-142
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• 2022

This study aims to develop a curriculum for nurturing experts who perform agricultural safety and health management tasks. This study was conducted in three stages. First, job definitions and job models of agricultural safety and health managers were derived through job analysis using the DACUM technique. Second, job demand analysis was conducted by conducting a survey on the difficulty, importance, and frequency of each task. Third, IPA analysis was performed as the first priority tasks of job demand analysis to present the courses and subjects of the training course for safety and health managers in agricultural work. The job of the agricultural safety and health manager was defined as "to conduct guidance and advice on safety and health education, risk factors, and evaluation and management of harmful factors to protect farmers' professional health and safety." The job model consisted of 4 tasks, 31 core tasks, and 67 detailed tasks. As a result of job demand analysis, there were 39 tasks in the 1st priority, 22 in the 2nd priority, and 6 in the 3rd priority. As a result of the IPA analysis, there were 13 'capacity development focused areas', 4 'capacity development effort areas', 11 'low priority areas', and 3 'continuous maintenance areas'.

• Journal of Digital Convergence
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• v.19 no.11
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• pp.365-371
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• 2021

In this study, The Virtual Power Plant (VPP) solution platform considered in this study minimizes the cost and investment risk associated with the construction of power generation and transmission facilities. In addition, it includes a Demand Response (DR) program operation function to meet consumers' electricity demand. With the introduction of VPP, it is possible to provide more eco-friendly and efficient power by responding to changes in consumer load in real time through existing generators and DR programs without large-scale facility investment in power generation and transmission/distribution sectors. In order to link the communication device to the solar power and ESS linkage device, it is necessary to transmit data in the control/state between the device device and the edge system and develop an IoT device and interworking platform (OneM2M).

• Resources Recycling
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• v.31 no.3
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• pp.27-39
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• 2022

The global demand for lithium-ion batteries (LIBs) has been continuously increasing since the 1990s along with the growth of the portable electronic device market. Of late, the rapid growth of the electric vehicle market has further accelerated the demand for LIBs. The demand for the LIBs is expected to surpass the supply of lithium from natural resources in the near future, posing a risk to the global lithium supply chain. Moreover, the continuous accumulation of end-of-life LIBs is expected to cause serious environmental problems. To solve these problems, recycling the spent LIBs must be viewed as a critical technological challenge that must be urgently addressed. In this study, recycling LIBs using pyrometallurgical processes and post-processes for efficient lithium recovery are briefly reviewed along with the major accomplishments in the field and current challenges.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.30 no.4
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• pp.105-116
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• 2022

Domestic and foreign aviation industries showed steep growth along with rapid increase in aviation demand, but the industries got directly hit by COVID-19. Now, with the recovery of daily life, aviation demand is gradually increasing, too. However, the risk of aviation accidents also increases proportionally to the increasing demand for aviation. Although it is a point that safety management needs to be actively conducted to prevent safety accidents resulted from the growth of aviation industries, research on safety culture and organizations is not sufficiently done in terms of the depth and scope of it despite the importance of the discussion. Studies in various areas have reported that an organization's safety culture forms the group's safety atmosphere and then results in the workers' safety behavior. Accordingly, this study examined the effects of safety culture in an organization on the safety behavior of its members who are aircraft maintenance technicians. The results of this research can be summed up as follows: first, it has been found that the roles of the person in charge grounded on clear goals and guidelines for the organization's safety policy influence the technicians' attitudes. Second, the important factor in the technicians' safety observance is that the attitude to follow safety rules when performing aviation maintenance raises their awareness of safety, for instance, following standard operation procedures or wearing personal equipment for protection. Third, their attitudes have positive effects on safety participation, and consequently, their intention to comply with safety rules is shown as an active action to achieve the ultimate goal of safety behavior.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.516-516
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• 2022

Agricultural reservoirs are critical water resources structures to ensure continuous water supplies for rice cultivation in Korea. Climate change has increased the risk of reservoir failure by exacerbating discrepancies in upstream runoff generation, downstream irrigation water demands, and evaporation losses. In this study, the variations in water balance components of 400 major reservoirs during 1973-2017 were examined to identify the reservoirs with reliable storage capacities and resilience. A conceptual lumped hydrological model was used to transform the incident rainfall into the inflows entering the reservoirs and the paddy water balance model was used to estimate the irrigation water demand. Historical climate data analysis showed a sharp warming gradient during the last 45 years that was particularly evident in the central and southern regions of the country, which were also the main agricultural areas with high reservoir density. We noted a country-wide progressive increase in average annual cumulative rainfall, but the forcing mechanism of the rainfall increment and its spatial-temporal trends were not fully understood. Climate warming resulted in a significant increase in irrigation water demand, while heavy rains increased runoff generation in the reservoir watersheds. Most reservoirs had reliable storage capacities to meet the demands of a 10-year return frequency drought but the resilience of reservoirs gradually declined over time. This suggests that the recovery time of reservoirs from the failure state had increased which also signifies that the duration of the dry season has been prolonged while the wet season has become shorter and/or more intense. The watershed-irrigated area ratio (W-I_ratio) was critical and the results showed that a slight disruption in reservoir water balance under the influence of future climate change would seriously compromise the performance of reservoirs with W-I_ratio< 5.

• Journal of Korean Society of Transportation
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• v.33 no.5
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• pp.478-487
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• 2015

This study proposed a Variable Speed Limits(VSL) algorithm to use traffic information based on Cumulative Demand-Capacity Analysis and evaluated its performance. According to the analysis result, the total of delay consisted of 3 separate parts. There was no change in total travel time although the total of delay decreased. These effects was analysed theoretically and then, evaluated through VISSIM, a microscopic simulator. VISSIM simulation results show almost same as those of theoretical analysis. Furthermore in SSAM analysis with VISSIM simulation log, the number of high risk collisions decreased 36.0 %. However, the total delay decrease effect is not real meaning of decrease effect because the drivers' desired speed is same whether the VSL model is operated or not. Nevertheless this VSL model maintains free flow speed for longer and increases the cycle of traffic speed fluctuation. In other words, this is decrease of delay occurrence and scale. The decrease of speed gap between upstream and downstream stabilizes the traffic flow and leads decrease number of high risk collision. In conclusion, we can expect increase of safety through total delay minimization according to this VSL model.