• Journal of Information Technology Applications and Management
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• v.28 no.1
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• pp.63-81
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• 2021

The advent of the convergence era led to the convergence of industries while increasing the uncertainty of R&D. R&D uncertainty can be addressed by identifying and addressing industrial innovation patterns, which Neo-Schumpeterian suggested can be identified through the process of identifying the technical characteristics of a particular industry, which can be embodied in the concept of technology trajectory. Thus, this study considered and proposed a method to track the technology trajectory of the convergence industry through topic modeling and patent citation network analysis, and applied it to the micro medical robot industry, which is a representative convergence industry, to track the technology trajectory of active catheter. In particular, it is intended to identify the unique characteristics of the industry by identifying the industry before the promotion of the national-led medical robot industry support policy. Therefore, we tried to understand the innovation pattern of the industry by tracking the technology trajectory of the industry before 2017, the time of full-scale support for the medical robot industry in the United States. Through tracking technology trajectories, the role of each technology classification, the development path, and the knowledge flow between applicants were analyzed empirically. The results of this study are expected to contribute to resolving the remaining uncertainties in the process of establishing an active catheter R&D strategy, one of the leading convergence industries, and furthermore, it is expected to be available for tracking technology trajectories in other industries.

• Journal of the Korean Society of Propulsion Engineers
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• v.25 no.5
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• pp.18-26
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• 2021

In this work, we have developed a 1D network model aimed at predicting eigenvalues for resonance frequency analysis in a lab-scale industrial gas turbine single nozzle combustion system. Modern industrial gas turbines generally adopt combustors with very complex geometry and flow path to meet various design requirements simultaneously. The current study has developed a network model for combustion systems with backflow at the same axial location. The modeling results of resonance frequencies and mode distributions for a given system using the network model were validated from comparisons with prediction results using a 3D Helmholtz solver.

• Journal of Naturopathy
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• v.10 no.1
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• pp.56-65
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• 2021

Purposes: This study is to examine the causes of limitations of modern western science and philosophy through Ayurvedic thought, and to seek the path of holism for the development of national healing projects. Methods: Therefore, it was inferred that the background of modern Western civilization and the reality of the national healing project would share the flow. In order to examine this, the difference between the East and West's 'recognition of the body and the mind' and the 'perspective on the origin of existence' was examined, and the characteristics of the Ayurvedic five-element novel were examined. Results: Through that process, the "mind and body dualism" in the West and the absence of the "empty element( 空 Śunya)" in Western four-element novels were pointed out as the cause of the limitations. In the sense that the 'empty element' is an invisible world and an immaterial world, it was concluded that the absence of justice was a limitation of Western civilization and a problem of the reality of the national healing project. Conclusions: I hope that this study will lead to continuous research on Ayurvedic ideology and research in the field of natural healing, thus contributing to the development of national healing projects and leading to health, well-being, and self-healing of the people.

• Applied Chemistry for Engineering
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• v.34 no.4
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• pp.383-387
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• 2023

The quartz crystal microbalance (QCM), commonly used in high vacuum deposition, becomes difficult to use when a thick film is deposited on the quartz, affecting the crystal's inherent vibration. In this study, a non-destructive optical measurement method was developed to measure the film's deposition rate during the in-situ film deposition process. By measuring the scattered laser intensity caused by the dimer in the parylene gas passing through the gas flow path, it was successfully confirmed that the ratio of the dimer in the parylene gas increases as the pyrolysis temperature decreases. Additionally, it was noted that the film's thickness and haze increase as the pyrolysis temperature decreases by confirming the characteristics of the visible parylene films. Through the research results, we aim to utilize the stable in-situ film deposition rate measurement system to control the precise film deposition rate of parylene films.

• Journal of Practical Agriculture & Fisheries Research
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• v.14 no.1
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• pp.3-22
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• 2012

Control independence has been put forward as a significant new source of instruction-level parallelism for superscalar processors. In branch prediction mechanisms, all instructions after a mispredicted branch have to be squashed and then instructions of a correct path have to be re-fetched and re-executed. This paper presents a new branch misprediction recovery mechanism to reduce the number of instructions squashed on a misprediction. Detection of control independent instructions is accomplished with the help of the static method using a profiling and the dynamic method using a control flow of program sequences. We show that the suggested branch misprediction recovery mechanism improves the performance by 2~7% on a 4-issue processor, by 4~15% on an 8-issue processor and by 8~28% on a 16-issue processor.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.3
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• pp.916-937
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• 2023

Most of the existing Distributed Denial-of-Service mitigation schemes in Software-Defined Networking are only implemented in the network domain managed by a single controller. In fact, the zombies for attackers to launch large-scale DDoS attacks are actually not in the same network domain. Therefore, abnormal traffic of DDoS attack will affect multiple paths and network domains. A single defense method is difficult to deal with large-scale DDoS attacks. The cooperative defense of multiple domains becomes an important means to effectively solve cross-domain DDoS attacks. We propose an efficient multi-domain DDoS cooperative defense mechanism by integrating blockchain and SDN architecture. It includes attack traceability, inter-domain information sharing and attack mitigation. In order to reduce the length of the marking path and shorten the traceability time, we propose an AS-level packet traceability method called ASPM. We propose an information sharing method across multiple domains based on blockchain and smart contract. It effectively solves the impact of DDoS illegal traffic on multiple domains. According to the traceability results, we designed a DDoS attack mitigation method by replacing the ACL list with the IP address black/gray list. The experimental results show that our ASPM traceability method requires less data packets, high traceability precision and low overhead. And blockchain-based inter-domain sharing scheme has low cost, high scalability and high security. Attack mitigation measures can prevent illegal data flow in a timely and efficient manner.

• Transactions of the Korean hydrogen and new energy society
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• v.34 no.1
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• pp.8-16
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• 2023

In this work, we report basic performance test results of a lab-scale three phase alternative current (AC) arc plasma torch system for plasma gas reforming applications. The suggested system primarily consists of three graphite electrodes inclined at 12.5° to the central axis, a 𝞥 150 mm cylindrical gas path and a three phase-60 Hz AC power supply. At air flow rate of 50 Lpm and arc currents of 100-175 A, test results revealed that plasma resistances were decreasing from 1.08 Ω to 0.53 Ω with the increase of plasma power from 9.3 kW to 13.8 kW, causing the decrease of power factor and increase of the line voltages. However, the injected air can be heated quickly up to the temperatures of >1,200℃ when injecting AC arc plasma powers of >10 kW.

• Journal of Korean Tunnelling and Underground Space Association
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• v.12 no.1
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• pp.31-41
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• 2010

This paper presents both numerical and physical modeling approaches for the dilation and spalling of rock recognized as typical process of rock around an underground opening at depth. For physical approach, laboratory testing of rectangular beams using a synthetic rock was used to investigate the onset of dilation and spalling. The beams are axially compressed and subjected to 4-point bending to provide non-uniform compressive stresses which are similar to the maximum tangential stress distribution around circular openings. Discrete element numerical analyses using commercial code $PFC^{2D}$ (Particle Flow Code) were performed to evaluate the stress path at various locations in the beams. The findings from these approaches suggest that the onset of dilation in laboratory tests appears to be a good indicator for assessing the stress magnitudes required to initiate spalling.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.4
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• pp.356-362
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• 2023

The risk of climate change has been long acknowledged, and ongoing efforts to overcome this issue, within the shipping sector, with the international maritime organization playing a central role. Conducting research on characteristics of soot formation is crucial to control its occurrence within the combustion process. In this study, the laser extinction method and chemical reaction numerical analysis were employed to examine the alterations in the state of chemical species associated with flame temperature, flame visual, and soot formation by mixing nitrogen, an inert gas, in the counterflow diffusion flame based on ethylene gas. The findings of the study suggest that as the mixing ratio of nitrogen increased, both the flame temperature and soot volume fraction decreased. Additionally, the area in which soot particles were distributed also decreased, and the volume fraction decrease rate declined when the mixing ratio increased by more than 30%. The mole fraction of the chemical species involved in soot growth also decreased. the chemical species associated with the HACA reaction were affected by variations in the hydrocarbon fuel ratio, and the chemical species related to the odd carbon path were confirmed to be affected by the flame temperature as well as the hydrocarbon fuel ratio.

• International conference on construction engineering and project management
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• 2020.12a
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• pp.63-74
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• 2020

The assembly of modular construction requires a series of thoroughly-considered decisions for crane lifting including the crane model selection, crane location planning, and lift path planning. Traditionally, this decision-making process is empirical and time-consuming, requiring significant human inputs. Recently, research efforts have been dedicated to improving lift planning practices by leveraging cutting-edge technologies such as automated data acquisition, Building Information Modelling (BIM) and computational algorithms. It has been demonstrated that these technologies have advanced lift planning to some degree. However, the advancements tend to be fragmented and isolated. There are two hurdles prevented a systematic improvement of lift planning practices. First, the lack of formalized lift planning workflow, outlining the procedure and necessary information. Secondly, there is also an absence of a shared information environment, enabling storages, updates and the distribution of information to stakeholders in a timely manner. Thus, this paper aims to overcome the hurdles. The study starts with a literature review in combination with document analysis, enabling the initial workflow and information flow. These were contextualised through a series of interviews with Australian practitioners in the crane-related industry, and systematically analysed and schematically validated through an expert panel. Findings included formalized workflow and corresponding information exchanges in a traditional lift planning practice via a Business Process Model and Notation (BPMN). The traditional practice is thus reviewed to identify opportunities for further enhancements. Finally, a BIM-based lift planning workflow is proposed, which integrates the scattered technologies (e.g. BIM and computational algorithms) with the aim of supporting lift planning automation. The resulting framework is setting out procedures that need to be developed and the potential obstacles towards automated lift planning are identified.