• International conference on construction engineering and project management
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• 2015.10a
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• pp.614-615
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• 2015

In these days, global construction market is speedily increasing and domestic construction companies have a chance of new contracts. In the meantime, international projects have been increasingly forced to cope with potential risks, which seriously impacted achieving the targeted time and cost. In this study, we introduce a computerized risk management system for international EPCS projects, which is constructed on the needs of practitioners and decision makers as an aid to proactively control the potential risks and to monitor continuously their status and variation. The system is called the Project Risk Management System (PRiMS) is useful for furnishing project managers with warning signals as a project is progressing and helpful for producing the total risk score and tracking risk variation.

• ETRI Journal
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• v.43 no.2
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• pp.357-370
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• 2021

The evolution of blockchain-based systems has enabled researchers to develop nextgeneration e-voting systems. However, the classical consensus method of blockchain, that is, Proof-of-Work, as implemented in Bitcoin, has a significant impact on energy consumption and compromises the scalability, efficiency, and latency of the system. In this paper, we propose a hybrid consensus model (PSC-Bchain) composed of Proof of Credibility and Proof of Stake that work mutually to address the aforementioned problems to secure e-voting systems. Smart contracts are used to provide a trustworthy public bulletin board and a secure computing environment to ensure the accuracy of the ballot outcome. We combine a sharding mechanism with the PSC-Bchain hybrid approach to emphasize security, thus enhancing the scalability and performance of the blockchain-based e-voting system. Furthermore, we compare and discuss the execution of attacks on the classical blockchain and our proposed hybrid blockchain, and analyze the security. Our experiments yielded new observations on the overall security, performance, and scalability of blockchain-based e-voting systems.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2007.12a
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• pp.51-55
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• 2007

This thesis deals with the legal principles, case law decisions and suggestions for the Sale & Purchase of ships concerning enactment proposal of maritime law. Recently, the shipbuilding market has shown a major shift towards East Asia, particularly Korea, Japan and China. The major Korean shipyards in particular have engaged in substantial investment programmes both to expand their overall shipbuilding capacity and to enter new markets, such as for liquefied natural gas(LNG) carriers. The Korean Government has recently taken interest in the sale & purchase of used ships, utilizing the Internet and has made plans for building the Shipping Exchange in korea. So this thesis examines the situation of the world's shipping industry and the different kinds of the Sale & Purchase of ships. deals with the legal principles, and case law decisions. describes Forms of Shipbuilding Contracts and Memorandums of Agreement of second-hand ships. And makes suggestions for 1) the Shipbuilding Contracts of the shipowner's Association of Korea and 2) The Korean Shipbrokers' Association's Memorandum of Agreement for Ship Sale & Purchase in the korean shipping industry. Having reached the end of this thesis. the writer suggests to make terms of sale of ships in the korean civil code and commercial code, Additionally. the writer suggests to make a special law in relation to the Sale & Purchase of ships. Furthermore, the writer suggests expanding the Shipping Exchange in Korea.

• Journal of the military operations research society of Korea
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• v.37 no.1
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• pp.49-70
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• 2011

This paper re-evaluated the research on the accounting information's effectiveness in military construction contracts, questioning the former research results on the central army's construction contract that was under the Qualification Assessment System, especially concerning the relations between the accounting information and the bidding ratios as well as the relations between the bidding rates and the defect rates, which targeted between 1 to 10 billions civil engineering, construction, electricity, telecommunication, and environment work types. Unlike the previous results, the relationship between the accounting information and the bidding rates was shown to be considerably limited that the bidding ratio could not be identified through the accounting information, while it could discern the relations with the defect rates. Furthermore, the proven results did not support the hypothesis that the differences in bidding rates could affect the defect ratio. However, through the prediction model of bidding and defect ratios, we could identity the accounting variables that influenced the ratios. Additionally through the results regarding the non-financial indexes in the Pre-Qualification items, the weight on these indexes could be adjusted. In conclusion, the research results has given us new understanding of the problems in the Qualification Assessment System which accounts for the majority of the current military construction contracts and provide validity on the government's expanded implementation of the Lowest Price Award System.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.3
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• pp.61-67
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• 2020

The fourth industrial revolution encourages manufacturing industry to pursue a new paradigm shift to meet customers' diverse demands by managing the production process efficiently. However, it is not easy to manage efficiently a variety of tasks of all the processes including materials management, production management, process control, sales management, and inventory management. Especially, to set up an efficient production schedule and maintain appropriate inventory is crucial for tailored response to customers' needs. This paper deals with the optimized inventory policy in a steel company that produces granule products under supply contracts of three targeted on-time delivery rates. For efficient inventory management, products are classified into three groups A, B and C, and three differentiated production cycles and safety factors are assumed for the targeted on-time delivery rates of the groups. To derive the optimized inventory policy, we experimented eight cases of combined safety stock and data analysis methods in terms of key performance metrics such as mean inventory level and sold-out rate. Through simulation experiments based on real data we find that the proposed optimized inventory policy reduces inventory level by about 9%, and increases surplus production capacity rate, which is usually used for the production of products in Group C, from 43.4% to 46.3%, compared with the existing inventory policy.

• Journal of Information Processing Systems
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• v.16 no.4
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• pp.935-958
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• 2020

The core value of finance is credit. It can be said that without credit, there can be no finance. The distributed structure of the blockchain and the low-cost trust-building mechanism based on mathematical algorithms provide a new solution and path for solving and optimizing related problems in the financial field. The blockchain technology is applied in the development of the financial industry through consensus mechanisms, smart contracts, and distributed networks. In this research, a comprehensive survey of the blockchain technology is proposed in the development of financial services including equity crowdfunding and credit investigations in inclusive finance, cross-border remittance, Internet financial payment, P2P lending, supply chains finance, and the application of blockchain in the field of anti-money laundering. This paper discusses the role of blockchain in solutions to different issues in the financial field. It also discusses the architectures in different financial service application scenarios from the perspective of the financial trust mechanism and the perspective of the technology and rule change of blockchain participation in financial innovation. Finally, the problems and challenges of blockchain in financial services are discussed, and corresponding solutions are proposed.

• KIEE International Transactions on Power Engineering
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• v.3A no.1
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• pp.53-60
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• 2003

At present the electric power industry in Korea is going through a major restructuring process. The restructuring is motivated by a desire to reduce electricity supply costs, to attract new in-vestment in modern generation, transmission and distribution facilities, and to stimulate innovation in the wholesale production and the retail supply of electricity. The experience to date shows that restructuring of electric power industry in the US, however, is marred with a number of problematic market performances including unreasonably high prices at wholesale. This paper investigates the important role of Power Exchange for stabilizing electric power industry in transition by offering various financial products. These financial products are used for risk hedging by the market participants. The paper focuses on the risk hedging by an individual supplier and derives an explicit decision rule that incorporates the attitude towards the risks. In addition to providing the financial products for risk hedging by market participants, the Power Exchange plays another very important role of financial safeguard system. Because of its unique characteristics, the Power Exchange is well suited for financial surveillance where it performs the early detection of unsound financial (and to a large extent operational) practices on the part of any system users and protect the system integrity and the market participants from the consequences of a default in the clearing structure.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.510-514
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• 2004

This research is a preliminary one to investigate transitional problems of actual-cost-date-based contract cost estimation method and suggestions for counteracting them. As parts of it, in this paper, the brief background and methods of the new method and contract costs estimated by introducing it are presented. The results of five projects' contract costs are compared to those estimated by the conventional quantity-based method. Comparison of the both is conducted in terms of total contract costs and contract costs according to type of sub-contracts. Finally, the propositional differences of the later to the former are analysed.

• Journal of Information Processing Systems
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• v.20 no.2
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• pp.273-283
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• 2024

The digital domain has witnessed unprecedented growth, reshaping the way we interact, work, and even perceive reality. The internet has evolved into a vast ecosystem of interconnected virtual worlds, giving birth to the concept of the Metaverse. The Metaverse, often envisioned as a collective virtual shared space, is created by the convergence of virtually enhanced physical reality and interactive digital spaces. Within this Metaverse space, the concept of ownership, identity, and authenticity takes on new dimensions, necessitating innovative solutions to safeguard individual rights. The digital transformation through Metaverse has also brought forth challenges, especially in copyright protection. As the lines between the virtual and physical blur, the traditional notions of ownership and rights are being tested. The Metaverse, with its multitude of user-generated content, poses unique challenges. The primary objective of this research is multifaceted. Firstly, there's a pressing need to understand the strategies employed by non-fungible token (NFT) marketplaces within the Metaverse to strengthen security and prevent copyright violations. As these platforms become centers for digital transactions, ensuring the authenticity and security of each trade becomes paramount. Secondly, the study aims to delve deep into the foundational technologies underpinning NFTs, from the workings of blockchain to the mechanics of smart contracts, to understand how they collectively ensure copyright protection. Thus, in this paper, we propose a quantum based NFT solution that can secure Metaverse and copyright contents in an advanced manner.

• Korean Journal of Construction Engineering and Management
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• v.9 no.3
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• pp.164-174
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• 2008

It is crucial In decision making to select a project delivery system (PDS) adjusted accordingly to the project characteristics. Furthermore, selecting a tendering system is the kernel in the process of selecting PDS. In October 2007, the Ministry of Finance and the Economy of Korea launched two new project delivery systems, "Best Value Contract (Design-Bid-Build)" and "Bridging Contracts (Design-Build)" by revising enforcement ordinances of "Act on Contracts to Which the State is a Party" to provoke the tendering systems. In order to support the proposed purpose, this research developed a selection model for suitable tendering system, which helps a public owner select a tendering system appropriate to the project characteristics. First, the framework of the model was set throughout analyzing previous researches and interviewing relevant experts. Additionally, by analyzing the survey result from 265 experts engaged in architectural and civil engineering business, the relative weights of the selection factors and the effectiveness values of the alternatives were suggested as the quantitative evaluation references. Finally, the practical guideline was suggested to apply this model to three public projects scheduled to be delivered. The result of applying the model to three case projects showed that further researches were needed to make the selection process logical and to suggest the standard weights and effectiveness values according to project type.