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Research of fast point cloud registration method in construction error analysis of hull blocks

  • Wang, Ji;Huo, Shilin;Liu, Yujun;Li, Rui;Liu, Zhongchi
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.12 no.1
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    • pp.605-616
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    • 2020
  • The construction quality control of hull blocks is of great significance for shipbuilding. The total station device is predominantly employed in traditional applications, but suffers from long measurement time, high labor intensity and scarcity of data points. In this paper, the Terrestrial Laser Scanning (TLS) device is utilized to obtain an efficient and accurate comprehensive construction information of hull blocks. To address the registration problem which is the most important issue in comparing the measurement point cloud and the design model, an automatic registration approach is presented. Furthermore, to compare the data acquired by TLS device and sparse point sets obtained by total station device, a method for key point extraction is introduced. Experimental results indicate that the proposed approach is fast and accurate, and that applying TLS to control the construction quality of hull blocks is reliable and feasible.

Privacy Aware Authentication Protocol for Cognitive Radio Networks (인지무선 네트워크를 위한 프라이버시가 강화된 인증 프로토콜)

  • Kim, Hyun-Sung
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.20 no.1
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    • pp.33-40
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    • 2010
  • Recently, the spectrum scarcity is becoming a big issue because there are exponential growth of broadcasting and communication systems in the spectrum demand. Cognitive radio is a technology that is envisaged to solve the problems in wireless networks resulting from the limited available spectrum and the inefficiency in the spectrum usage by exploiting the existing wireless spectrum opportunistically. Kuroda et al. proposed a radio-independent authentication protocol for cognitive radio networks. This paper first shows the privacy weaknesses in the authentication protocol by Kuroda et al. and proposes a privacy aware authentication protocol to solve the weaknesses.

Nerve Cable Graft Interposition in Patients with Brachial Plexus Schwannoma: Case Reports

  • Han, Changsung;Ahn, Hyo Yeong;Kim, Yeong Dae;Lee, Chung Won
    • Journal of Chest Surgery
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    • v.54 no.6
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    • pp.535-538
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    • 2021
  • Schwannomas are rare benign tumors that develop in Schwann cells lining peripheral nerves. Schwannomas of the brachial plexus are especially rare, accounting for 5% of all cases. Although several treatments can be considered, the exact method of treatment is unclear owing to the scarcity and sporadic occurrence of schwannomas. Tumor resection is performed in most cases, and nerve damage is inevitable in cases of neuroinvasive schwannoma. In this case series, we present our successful use of transposition of cable-grafted nerves for the treatment of schwannomas. We performed cable-grafted nerve interposition in addition to tumor resection, leading to increased recovery of nerve damage. To relieve postoperative symptoms and minimize sequelae, precise surgical tumor resection followed by nerve interposition using a cable-grafted nerve may be recommended.

On the intra-granular behaviour of a cocktail of inert gases in oxide nuclear fuel: Methodological recommendation for accelerated experimental investigation

  • Romano, M.;Pizzocri, D.;Luzzi, L.
    • Nuclear Engineering and Technology
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    • v.54 no.5
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    • pp.1929-1934
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    • 2022
  • Besides recent progresses in the physics-based modelling of fission gas and helium behaviour, the scarcity of experimental data concerning their combined behaviour (i.e., cocktail) hinders further model developments. For this reason, in this work, we propose a modelling methodology aimed at providing recommendations for accelerated experimental investigations. By exploring a wide range of annealing temperatures and cocktail compositions with a physics-based modelling approach we identify the most interesting conditions to be targeted by future experiments. To corroborate the recommendations arising from the proposed methodology, we include a sensitivity analysis quantifying the impact of the model parameters on fission gas and helium release, in conditions representative of high and low burnup.

Comparative investigation on fatigue and moisture absorption behavior of hemp and Jute fibre polymer composites

  • Kumar, B. Ravi;Hariharan, S.S.
    • Structural Engineering and Mechanics
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    • v.81 no.6
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    • pp.729-736
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    • 2022
  • Earth is facing a serious problem of pollution and scarcity of energy sources. The synthetic fibers used in automobile and Aerospace manufacturing sectors are non-renewable and harmful to environment. International Agency such as FAA and SAE is forcing for green fuel, green materials and structures. Further exploration is much needed to understand its potential in structural applications. In the current study, hemp and Jute fibre based composites were developed and tested for assessing their suitability for possible applications in automobile and aerospace sectors. Composites were undergone tensile test, water absorption test, and fatigue analysis to understand its behavior under various loading conditions. The finite element analysis has been carried out to understand the fatigue behaviour of composites. The results revealed that the usage of hemp and jute fibre reinforced composites can improve mechanical properties and have shown a viable alternative to replace synthetic fibres such as glass fibres for specific applications. Hemp reinforced bio-composites have shown better performance as compared to Jute reinforced bio-composites while water resistance characteristics for hemp is poorer to jute fibres.

Mediastinal Lymph Node Dissection in Gastroesophageal Junction Adenocarcinoma

  • Jin-Jo Kim
    • Journal of Gastric Cancer
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    • v.23 no.1
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    • pp.171-181
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    • 2023
  • Currently, the prevalence of gastroesophageal junction adenocarcinoma (GEJAC) is increasing in both Asian and Western countries, although the increasing rate in Asian countries is much slower than in Western countries. With these current trends, concerns regarding the surgical treatment method are also increasing among gastrointestinal surgeons. However, the surgical treatment for GEJAC has been a controversial issue for a long time due to the relative scarcity of this tumor and its characteristics from its borderline location. Recently, a large-scale prospective study of this tumor has been conducted in Japan, and the results are now available. The results of this study will be helpful for understanding this tumor. In this article, the pattern of lymph node metastasis of GEJAC is reviewed, and the extent and method of lymph node dissection for this tumor are discussed and proposed based on the review.

Optimized biodiesel yield in a hydrodynamic cavitation reactor using response surface methodology

  • Neeraj Budhraja;R.S. Mishra
    • Advances in Energy Research
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    • v.8 no.4
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    • pp.233-241
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    • 2022
  • Biodiesel is a non-polluting and non-toxic energy source that can replace conventional diesel. However, the higher production cost and raw material scarcity became challenges that obstruct the commercialization of biodiesel production. In the current investigation, fried cooking oil is used for biodiesel production in a hydrodynamic cavitation reactor, thus enhancing raw material availability and helping better waste oil disposal. However, due to the cavitation effect inside the reactor, the hydrodynamic cavitation reactor can give biodiesel yield above 98%. Thus, the use of orifice plates (having a different number of holes for cavitation) in the reactor shows more than 90% biodiesel yield within 10 mins of a time interval. The effects of rising temperature at different molar ratios are also investigated. The five-hole plate achieves the highest yield for a 4.5:1 molar ratio at 65℃. And the similar result is predicted by the response surface methodology model; however, the optimized yield is obtained at 60℃. The investigation will help understand the effect of hydrodynamic cavitation on biodiesel yield at different molar ratios and elevated temperatures.

Improving streamflow and flood predictions through computational simulations, machine learning and uncertainty quantification

  • Venkatesh Merwade;Siddharth Saksena;Pin-ChingLi;TaoHuang
    • Proceedings of the Korea Water Resources Association Conference
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    • 2023.05a
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    • pp.29-29
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    • 2023
  • To mitigate the damaging impacts of floods, accurate prediction of runoff, streamflow and flood inundation is needed. Conventional approach of simulating hydrology and hydraulics using loosely coupled models cannot capture the complex dynamics of surface and sub-surface processes. Additionally, the scarcity of data in ungauged basins and quality of data in gauged basins add uncertainty to model predictions, which need to be quantified. In this presentation, first the role of integrated modeling on creating accurate flood simulations and inundation maps will be presented with specific focus on urban environments. Next, the use of machine learning in producing streamflow predictions will be presented with specific focus on incorporating covariate shift and the application of theory guided machine learning. Finally, a framework to quantify the uncertainty in flood models using Hierarchical Bayesian Modeling Averaging will be presented. Overall, this presentation will highlight that creating accurate information on flood magnitude and extent requires innovation and advancement in different aspects related to hydrologic predictions.

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Generating a Simplistic 3D Model for Mobile Platform Applications

  • Ahmed, Naveed;Park, Jee Woong;Morris, Brendan
    • International conference on construction engineering and project management
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    • 2022.06a
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    • pp.1093-1099
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    • 2022
  • The number of buildings is increasing day by day. The next logical footstep is tackling challenges regarding scarcity of resources and sustainability, as well as shifting focus on existing building structures to renovate and retrofit. Many existing old and heritage buildings lack documentation, such as building models, despite their necessity. Technological advances allow us to use virtual reality, augmented reality, and mixed reality on mobile platforms in various aspects of the construction industry. For these purposes, having a BIM model or high detail 3D model is not always necessary, as a simpler model can serve the purpose within many mobile platforms. This paper streamlines a framework for generating a lightweight 3D model for mobile platforms. In doing so, we use an existing structure's site survey data for the foundation data, followed by mobile VR implementation. This research conducted a pilot study on an existing building. The study provides a process of swiftly generating a lightweight 3D model of a building with relative accuracy and cost savings.

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Calibration for Gingivitis Binary Classifier via Epoch-wise Decaying Label-Smoothing (라벨 스무딩을 활용한 치은염 이진 분류기 캘리브레이션)

  • Lee, Sanghyun
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2021.10a
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    • pp.594-596
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    • 2021
  • Future healthcare systems will heavily rely on ill-labeled data due to scarcity of the experts who are trained enough to label the data. Considering the contamination of the dataset, it is not desirable to make the neural network being overconfident to the dataset, but rather giving them some margins for the prediction is preferable. In this paper, we propose a novel epoch-wise decaying label-smoothing function to alleviate the model over-confidency, and it outperforms the neural network trained with conventional cross entropy by 6.0%.

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