• Journal of Industrial Convergence
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• v.18 no.5
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• pp.23-29
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• 2020

The Internet of things (IoT) is the extension of Internet connectivity into various devices and everyday objects. Embedded with electronics, Internet connectivity and other forms of hardware. The IoT poses significant risk to the entire digital ecosystem. This is because so many of these devices are designed without a built-in security system to keep them from being hijacked by hackers. This paper proposed a mutual authentication protocol for IoT Devices using symmetric-key algorithm. The proposed protocol use symmetric key cryptographic algorithm to securely encrypt data on radio channel. In addition, the secret key used for encryption is random number of devices that improves security by using variable secret keys. The proposed protocol blocked attacker and enabled legal deives to communicate because only authenticated devices transmit data by a mutual authentication protocol. Finally, our scheme is safe for attacks such as eavesdropping attack, location tracking, replay attack, spoofing attack and denial of service attack and we confirmed the safety by attack scenario.

• Korean Journal of Construction Engineering and Management
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• v.15 no.2
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• pp.33-43
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• 2014

Goods, services and construction works needed by central government entities, local government entities, and other public institutions are procured with national budget. For efficient budget execution, Article 9 Paragraph 1 of the Enforcement Decree of the Act on Contracts to Which the State is a Party (hereinafter "State Contract Act") provides for the criteria for determining estimated price. Sub-paragraph 2 of the paragraph provides for the "determination of estimated price by cost calculation". On this legal basis, pricing criteria for the determination of estimated price, based on the project purpose, are announced by responsible authorities. This study analyzes the pricing criteria for technology services and proposes a price calculation methodology that can ensure transparency, as a practical improvement for more rational and efficient budget execution in the public sector.

• Korean Journal of Construction Engineering and Management
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• v.19 no.4
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• pp.70-81
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• 2018

Claims in the construction industry can have a serious impact on the profitability of the project or can even result in project failure if it fails to take appropriate prevention. In order to properly prevent and respond to the potential claims and legal disputes throughout the project execution, it is necessary to continuously accumulate informations and clearly define the roles and responsibilities of the important activities systematically. Based on these needs, this study develops and verifies the project information management system(PMIS) that can prevent and respond possible claims for construction projects. Developed system includes such management modules as schedule, cost, PM/CM, design, collaboration, and claims. The system was validated by adopting it to the practical projects. The results showed that information systems tailored to the construction claim need to elevate users' familiarity to be more useful. Besides, the system can be more functional when used by both owners and contractors.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.8
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• pp.942-949
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• 2012

In order to ensure the safety of the large-scale public facilities, the analysis of EMC(ElectroMagnetic Compatibility) of electronic systems included in the facilities is very necessary. The reason is that the system-level EMC of the facility could be not guaranteed, even if individual equipments included in the facility are satisfied with their EMC requirements. As a result, the system-level evaluation and analysis of EMC should be carried out in order to establish the reliable operations of safety and mission-critical electronic systems. This paper analyze the relevant legal systems of domestic and other countries, and furthermore case studies of system-level EMC approaches were analyzed in the specific applications of electric railways, building, automobile, petroleum refinery systems. And the introduction of related systems in Korea is proposed, and main parts and problems to be looked at each proposed measures are discussed. The results are expected to be utilized in the introduction of the system-level EMC engineering, and contributed in national security and the protection of people's life, body and their properties.

• Journal of the Korean Institute of Landscape Architecture
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• v.21 no.4
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• pp.113-129
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• 1994

This study is designed to analyze the trends of professional services in Landscape Architecture during the past 5 years(1987-1991) in Korea. The data were collected from 1,117 projects from 56 engineering and landscape architecture firms. The findings are summarized as follows: 1) The projects have been increased annually by 19 percent in numbers and by 47 percent in money terms. 2) The main sources of projects are local governments and corporations. However the private sector comprise 31 percent in projects number and 46 percent in money terms. 3) The public park and tourism site development comprise a half of the projects. Recently recreational forest, golf, amusement and large housing site development have increased very rapidly. 4) In terms of workscope they are devided by 'complex' project which include extensive engineering works and 'simple' project which contain mostly planting design. The former include receational project with average 5 or 6 months contract period, and the later include housing and building site design with 2 or 3 months period. 5) Two types of consulting firms are typical. One is comprehensive engineering firms with urban planning section and few landscape section. The other is specialized professional firms with urban planning or landscape architecture. 50 percent of the project was done by comhensive engineering firms and 60 percent was done by urban planning section. The implication of these findings are broad: Firstly, We have to meet the demands in private secter mostly in recreation and leisure related projects. Secondly, landscape architects and project managers need more professional skills and coordination ability to deal with 'complex' projects. Thirdly, to enhance the quality of professional services it is required to have enough work time and higher service fee through legal and institutional enforcements.

• Fire Science and Engineering
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• v.31 no.4
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• pp.1-6
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• 2017

A fire resistance certification needs to be obtained before fire protection paint can be used in Korea. In the case of paint, the tests for certification are fire, gas hazard and bond strength. According to the hazard test standard of combustion gas, 16 mice are sacrificed every test. Therefore, there are ethical problems for the experimenter and legal problems for the laboratory. Accordingly, many alternatives are being assessed, such as combustion gas analysis, but they have not replaced animal testing yet. With gas hazard testing, the exhaust gas temperature can be measured. The property of the initial reaction of a specific fire paint can be characterized by this temperature. The purpose of this study was to consider the improvement point for a gas hazard test through comparative analysis of the exhaust temperature and the time of death of the mice.

• Structural Engineering and Mechanics
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• v.20 no.1
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• pp.85-110
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• 2005

This paper aims at formulating various statistical models for the study of a ten year Weigh-in-Motion (WIM) data collected from various WIM stations in Hong Kong. In order to study the bridge live load model it is important to determine the mathematical distributions of different load affecting parameters such as gross vehicle weights, axle weights, axle spacings, average daily number of trucks etc. Each of the above parameters is analyzed by various stochastic processes in order to obtain the mathematical distributions and the Maximum Likelihood Estimation (MLE) method is adopted to calculate the statistical parameters, expected values and standard deviations from the given samples of data. The Kolmogorov-Smirnov (K-S) method of approach is used to check the suitability of the statistical model selected for the particular parameter and the Monte Carlo method is used to simulate the distributions of maximum value stochastic processes of a series of given stochastic processes. Using the statistical analysis approach the maximum value of gross vehicle weight and axle weight in bridge design life has been determined and the distribution functions of these parameters are obtained under both free-flowing traffic and dense traffic status. The maximum value of bending moments and shears for wide range of simple spans are obtained by extrapolation. It has been observed that the obtained maximum values of the gross vehicle weight and axle weight from this study are very close to their legal limitations of Hong Kong which are 42 tonnes for gross weight and 10 tonnes for axle weight.

• Journal of Korean Society of Water and Wastewater
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• v.33 no.1
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• pp.63-77
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• 2019

Traditional wastewater research mainly focuses on 1) estimating the amount of waste entering sewage treatment facilities, 2) evaluating the treatment efficiency of sewage facilities, 3) investigating the role of sewage treatment effluent as a point source, and 4) designing and managing sewage treatment facilities. However, since wastewater contains a variety of chemical and biological substances due to the discharge of human excreta and material used for daily living into it, the collective constituents of wastewater are likely a reflection of a community's status. Wastewater-based epidemiology (WBE), an emerging and promising field of study that involves the analysis of substances in wastewater, can be applied to monitor the state of a defined community. WBE provides opportunities for exploiting indicators in wastewater to fulfill various objectives. The data analyzed under WBE are those pertaining to selected natural and anthropogenic substances in wastewater that are a result of the discharge of metabolic excreta, illicit or legal drugs, and infectious pathogens into the wastewater. This paper reviews recent progress in WBE and addresses current challenges in the field. It primarily discusses several representative applications including the investigation of drug consumption across different communities and the management of community disease and health. Finally, it summarizes established indicators for WBE.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.1
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• pp.103-110
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• 2019

Electronic voting has been followed by a lot of research as it provides convenience to voters and increases participation rates. Nevertheless, electronic voting has not been widespread yet. The existing electronic voting system does not guarantee credibility, and there arises a question on the security that the voting could be forged or altered by the attack to the central server. In this paper, we proposed blockchain based systems to solve the problems in electronic voting. Although the blockchain may guarantee the security of transaction data, there have been only a few electronic voting systems implemented using the blockchain. We developed blockchain enabled voting and brought out some of its related legal, technical and operational challenges to enforce more security in voting. Unlike centralized voting, the systems could enforce security and solve the problems such as forgery or alteration of transaction data caused by hacking or any attempts to gain control of the central server system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.2
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• pp.445-466
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• 2022

As everything linking to the internet, people can subscribe to various services from a service provider to facilitate their lives through the Internet of Things (IoT). An obligatory thing for the service provider is that they should push the service data safely and timely to multiple IoT terminal devices regularly after the IoT devices accomplishing the service subscription. In order to control the service message received by the legal devices as while as keep the confidentiality of the data, the public key encryption algorithm is utilized. While the existing public encryption algorithms for push service are too complicated for IoT devices, and almost of the current subscription schemes based on push mode are relying on centralized organization which may suffer from centralized entity corruption or single point of failure. To address these issues, we design a secure subscription-push service scheme based on blockchain and edge computing in this article, which is decentralized with secure architecture for the subscription and push of service. Furthermore, inspired by broadcast encryption and multicast encryption, a new encryption algorithm is designed to manage the permissions of IoT devices together with smart contract, and to protect the confidentiality of push messages, which is suitable for IoT devices. The edge computing nodes, in the new system architecture, maintain the blockchain to ensure the impartiality and traceability of service subscriptions and push messages, meanwhile undertake some calculations for IoT devices with limited computing power. The legalities of subscription services are guaranteed by verifying subscription tags on the smart contract. Lastly, the analysis indicates that the scheme is reliable, and the proposed encryption algorithm is safe and efficient.