• Journal of the Korean Solar Energy Society
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• v.21 no.1
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• pp.21-25
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• 2001

A methodology to predict the output performance of small hydro power using discharge of sewage treatment plant has been studied. Two sewage treatment plants existing in Chunrabuk-Do were selected and the output performance characteristics for these plants were analyzed, using developed model. As a result, it was found that the developed model in this study can be used to analyze the output characteristics for small hydro power using discharge of sewage treatment plant. Additionally, primary design specifications such as design flowrate, capacity, operational rate and annual electricity production were estimated and discussed for two plants.

• Water Engineering Research
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• v.2 no.1
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• pp.11-19
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• 2001

A performance prediction model for Small Hydro Power(SHP) sites has been studied and developed. Twelve SHP sites were selected and the performance characteristics were analyzed by using the developed model. Also, primary design specifications such as design flowrate, plant capacity, operational rate were suggested and feasibility for small hydro power sites were estimated. It was found that the design flowrate is most important parameter to exploit SHP plant and the methodology developed in this study can be a useful tool to analyze the performance of SHP sites.

• Proceedings of the Safety Management and Science Conference
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• 2008.11a
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• pp.569-578
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• 2008

The aim of this study is to propose economical safety driving speed index which those are geometric road status; examine the levels of which those cost-benefit of driving fuel expenditure; are search road safety design and operational technology for driving simulators. For the objective, we analyzed the current status of driving fuel expenditure and driving scenarios by the road alignments, and reviewed driving and technical specifications by the geometric types of road according to the implementation, and extended completion. Throughout the result of this study, diverse related driving information provision service, efficiently driving system is expected to be implemented in the national highway design system.

• ETRI Journal
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• v.43 no.2
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• pp.173-183
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• 2021

As low-power wide-area network (LPWAN) end devices (EDs) are deployed in massive scale, their economic and environmental costs of operation are becoming too significant to ignore and too difficult to estimate. While LPWAN architectures and protocols are designed to primarily save energy, this study shows that energy saving does not necessarily lead to lower cost or environmental footprint of the network. Accordingly, a theoretical framework is proposed to estimate the operational expenditure (OpEx) and environmental footprint of LPWAN EDs. An extended constrained optimization model is provided for the ED link assignment to gateways (GWs) based on heterogeneous ED configurations and hardware specifications. Based on the models, a simulation framework is developed which demonstrates that OpEx, energy consumption, and environmental footprint can be in conflict with each other as constrained optimization objectives. We demonstrate different ways to achieve compromises in each dimension for overall improved network performance.

• International Journal of Computer Science & Network Security
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• v.22 no.11
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• pp.357-366
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• 2022

Artificial intelligence (AI) is the replication of human intelligence by computer systems and machines using tools like machine learning, deep learning, expert systems, and natural language processing. AI can be applied in administrative settings to automate repetitive processes, analyze and forecast data, foster social communication skills among staff, reduce costs, and boost overall operational effectiveness. In order to understand how AI is being used for administrative duties in various organizations, this paper gives a critical dialogue on the topic and proposed a framework for using artificial intelligence in organizations. Additionally, it offers a list of specifications, attributes, and requirements that organizations planning to use AI should consider.

• Journal of Positioning, Navigation, and Timing
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• v.13 no.1
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• pp.35-44
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• 2024

This investigation primarily focuses on the generational characteristics of satellites utilized in the existing Global Navigation Satellite System (GNSS) and Regional Navigation Satellite System (RNSS), with a central emphasis on comparing the operational status of the latest generation satellites. Variations among satellite generations in physical attributes, energy consumption, and timekeeping are observed, enabling an exploration of the developmental trends over successive generations. Through a comparative analysis of the latest generation satellites, particularly in terms of performance, this study aims to furnish essential insights into the satellites employed within each system. Consequently, it will contribute to a foundational understanding of the past, present, and future GNSS satellites.

• Journal of Korean Society of Transportation
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• v.22 no.1 s.72
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• pp.19-30
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• 2004

Once baggage demand of passengers is forecast, BHS requirements must be analyzed, i.e., the number of originating/transferring/terminating bags to be handled, the number of conveyor lines to be installed, the number of containers for baggage make-up, the number of claim devices for baggage claim, and so on. Therefore, the determination of the baggage traffic volume is one of the most important analysis components for the airport design. Accordingly, this research proposes time-based distribution table models in order to accurately estimate BHS requirements to obtain design criteria in airport design phase. As the BHS requirements are ascertained, related requirements of the facilities can be determined by applying actual specifications of devices, i.e., throughput. This research found that the proposed mathematical model gives a good reflection of IIA (Incheon International Airport)'s operational condition. That means the model provides apparent reliability and feasibility. Furthermore, the specifications of devices are the newest figures. This fact supports that the research provides more effcient and reliable results.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.3
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• pp.311-318
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• 2014

Electromagnetic compatibility(EMC) performance of the first Korea space launch vehicle(KSLV-I) should be ensured and verified in order to guarantee the normal operation among the spacecraft, ground facilities which are installed in the space center, and other wireless communication networks. For the purpose of the EMC performance verification, pertinent EMC test specifications, methods, and procedures for both the subsystems and the system should be established in consideration of operational properties and electromagnetic environmental effects. And it is required to maintain and control the EMC properties consistently in accordance with the determined specifications up to the program closing phase. In this paper, sequential management work conducted during the overall development process of the KSLV-I is explained, and not only the phased EMC test plan for each model of the KSLV-I and its subsystem but also test method, specification, and results of the verification tests are presented. And also, multipaction analysis results are presented.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.4
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• pp.103-111
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• 2021

In modern society, digital lifestyles are spreading to minimize contact with people and to receive contactless information. The spread trend has established an unmanned distribution system in which transactions through contactless technologies such as kiosks and chatbots are activated in face-to-face transactions with sellers and consumers. In order to streamline logistics supply worldwide, digital new deal based joint logistics hubs, unmanned courier storage platforms, and fresh logistics based last mile services have been developed into unmanned logistics systems, focusing on the intelligent logistics system automation process. Unmanned courier storage system installed in urban areas and home to daily logistics where volume is concentrated are provided with fresh logistics services through cold chain and receiving freights in contactless environments. Development is also underway to minimize safety accidents caused by courier services, such as managing various information based on the integrated control system. This paper defines the concept of integrated operation for the development of a platform for contactless unmanned courier storage device developed into next-generation logistics system. In addition, we intend to develop systems engineering-based output for deriving safety requirements and specifications by identifying risk sources that may occur in the operational scenario. Therefore, the goal is to establish a foundation for safety and reliability between interfaces of logistics systems to be installed in apartment and subway station environments that want to provide unmanned logistics services to various consumers.

• Progress in Superconductivity and Cryogenics
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• v.25 no.3
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• pp.49-55
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• 2023

This paper presents the design of a re-liquefaction system as a BOG (boil-off gas) handling process in liquid hydrogen transport vessels. The total capacity of the re-liquefaction system was assumed to be 3 ton/day, with a BOR (boil-off rate) of 0.2 %/day inside the cargo. The re-liquefaction cycle was devised using the He-Brayton Cycle, incorporating considerations of BOG capacity and operational stability. The primary components of the system, such as compressors, expanders, and heat exchangers, were selected to meet domestically available specifications. Case studies were conducted based on the specifications of the components to determine the optimal design parameters for the re-liquefaction system. This encompassed variables such as helium mass flow rate, the number of compressors, compressor inlet pressure and compression ratio, as well as the quantity and composition of expanders. Additionally, an analysis of exergy destruction and exergy efficiency was carried out for the components within the system. Remarkably, while previous design studies of BOG re-liquefaction systems for liquid hydrogen vessels were confined to theoretical and analytical realms, this research distinguishes itself by accounting for practical implementation through equipment and system design.