• Journal of Hydrogen and New Energy
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• v.35 no.1
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• pp.14-26
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• 2024

Global efforts continue with the goal of transition to a "carbon neutral (net zero)" society with zero carbon emissions by 2050. For this purpose, the technology of water electrolysis is being developed, which can store electricity generated from renewable energies in large quantities and over a long period of time as hydrogen. Recently, various research and large-scale projects on 'green hydrogen', which has no carbon emissions, are being conducted. In this paper, a comparison of water electrolysis technologies was carried out and, based on data provided by the International Energy Agency (IEA), large-scale water electrolysis demonstration projects were analyzed by classifying them by technology, power supply, country and end user. It is expected that through the analysis of large-scale water electrolysis demonstration projects, research directions and road maps can be provided for the development/implementation of commercial projects in the future.

• Journal of Information Processing Systems
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• v.15 no.6
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• pp.1438-1448
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• 2019

We present a new technique, called VED (very effective debugging), for detecting and correcting division by zero errors for all types of .NET application. We use applications written in C# because C# applications are distributed through the internet and its executable format is used extensively. A tool called Immunity Debugger is used to reverse engineer executable code to get binaries of source code. With this technique, we demonstrate integer division by zero errors, the location of the error causing assembly language code, as well as error recovery done according to user preference. This technique can be extended to work for other programming languages in addition to C#. VED can work on different platforms such as Linux. This technique is simple to implement and economical because all the software used here are open source. Our aims are to simplify the maintenance process and to reduce the cost of the software development life cycle.

• Construction Engineering and Management
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• v.23 no.2
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• pp.49-54
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• 2022

• IEMEK Journal of Embedded Systems and Applications
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• v.19 no.5
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• pp.243-250
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• 2024

This study explores enhancing facial recognition performance in low-light environments using deep learning-based low-light enhancement techniques. Facial recognition technology is widely used in edge devices like smartphones, smart home devices, and security systems, but low-light conditions reduce accuracy due to degraded image quality and increased noise. We reviewed the latest techniques, including Zero-DCE, Zero-DCE++, and SCI (Self-Calibrated Illumination), and applied them as preprocessing steps in facial recognition on edge devices. Using the K-face dataset, experiments on the Qualcomm QRB5165 platform showed significant improvements in F1 SCORE from 0.57 to 0.833 with SCI. Processing times were 0.15ms for SCI, 0.4ms for Zero-DCE, and 0.7ms for Zero-DCE++, all much shorter than the facial recognition model MobileFaceNet's 5ms. These results indicate that these techniques can be effectively used in resource-limited edge devices, enhancing facial recognition in low-light conditions for various applications.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.3
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• pp.22-30
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• 2006

In this paper, a systematic design method on an IPMC(ionic polymer-metal composite)-driven ZNMF(zero-net-mass-flux) pump is introduced for the flow control of an MAV's (micro air vehicle) wing. Since the IPMC is able to generate a large deformation under a low input voltage along with its ability to operate in air, and is easier to be manufactured in a small size, it is considered to be an ideal material of the actuating diaphragm. Through the numerical methods, an optimal shape of the IPMC　diaphragm was found for maximizing the stroke volume. Based on the optimal IPMC diaphragm, a proto-type ZNMF pump with a slot, was designed. By using the flight speed of the MAV considered in this work, the driving frequencies(~ 40 Hz) of IPMC diaphragm, and the flow velocity through the pump's slot, the calculated non-dimensional frequency and the momentum coefficient ensure the feasibility of the designed ZNMF pump as a flow control device.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.276-284
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• 2009

As an on-going research project, Zero Net Energy Test Home (ZNETH) project investigates effective approaches to achieve whole-house environmental and energy goals. The main research objectives are (1) to identify energy saving solutions for designs, materials, and construction methods for the ZNETH house and (2) to verify whether ZNETH house can produce more energy than the house uses by utilizing Building Information Modeling (BIM) and energy analysis tools. The initial project analysis is conducted using building information modeling (BIM) and energy analysis tools. The BIM-driven research approach incorporates architectural and construction engineering methods for improving whole-building performance while minimizing increases in overall building cost. This paper discusses about advantages/disadvantages of using BIM integrated energy analysis, related interoperability issues between BIM software and energy analysis software, and results of energy analysis for ZNETH. Although this investigation is in its early stage, several dramatic outcomes have already been observed. Utilizing BIM for energy analysis is an obvious benefit because of the ease by which the 3D model is transferred, and the speed that an energy model can be analyzed and interpreted to improve design. The research will continue to use the ZNETH project as a testing bed for the integration of sustainable design into the BIM process.

• Land and Housing Review
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• v.15 no.2
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• pp.19-28
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• 2024

This study analyzes the potential to achieve carbon neutrality through the technical definition and case studies of carbon-neutral buildings. In line with the Paris Agreement of December 2015, the global community has committed to limiting the average temperature rise to below 2oC and striving to restrict it to 1.5oC above pre-industrial levels. Achieving this requires reaching a net-zero state by 2050 and necessitates transitions across various sectors including energy, land use, and transportation. This research explores the technological approaches and real-world examples of carbon-neutral buildings, assessing their feasibility and limitations. By examining the definition of carbon-neutral buildings and presenting various technological solutions and case studies from both domestic and international contexts, this study evaluates the effectiveness and practicality of carbon-neutral buildings. The findings offer specific guidelines for the design, construction, and operation of carbon-neutral buildings and provide practical information for policymakers and practitioners aiming to create sustainable built environments.

• Journal of the Korea Society of Computer and Information
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• v.21 no.5
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• pp.161-166
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• 2016

This paper suggests heuristic algorithm with O(m) linear time complexity for choice of expansion projects that can't be obtain the optimal solution using linear programming until now. This algorithm ascending sort of net profit for all projects. Then, we apply a simple method that deletes the project with minimum net profit until this result satisfies the carried over for n-years more than zero value. While this algorithm using simple rule, not the linear programing fails but the proposed algorithm can be get the optimal solution for experimental data.

• Informatization Policy
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• v.25 no.1
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• pp.3-29
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• 2018

The Federal Communications Commission voted to repeal net neutrality protections on December 14, 2017. This is the very opposite decision of the net neutrality rule that the Obama administration has consistently maintained. The ensuing storm from the repeal of net neutrality protections has an extensively effect enough on individuals and businesses to cover the entire spectrum, and the impact is hard to assess in the U. S. content industry, which dominates the worldwide Internet content and platform market. On the other hand, Korea's net neutrality protections have been firmly pursued, and there is no sign of change even after the decision happened in the U. S. Net neutrality is not a simple theme that is associated with the Constitution, such as freedom of expression, as well as the issue of network enhancement to prepare for 5G. Accordingly, this study examines how the net neutrality has been carried out in the U. S. and Korea over the years, and provides the issues of Internet enhancement, perspectives of ISP and ICP, and implications for the Constitution, market economy, fair competition and zero rating. This research delivers future direction and implications of domestic net neutrality policies.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.522-527
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• 2001

Comprehensive numerical computations are made of side-heated squire cavity which is exposed to zero mean g-jitter. Numerical solutions are acquires to the governing two-dimensional Navier-Stokes equations for a Boussinesq fluid. When the system is exposed to pure sinusoidal g-jitter inclined to the vertical axis, in spite of zero mean gravity there exist non zero net flow fields [8]. The resonance phenomenon are observed in moderate Rayleigh number. And, by comprehensive numerical work, unlike[5], it is found that they are related with the overshoot phenomenon of the sudden gravity up problem.