• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권3호
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• pp.958-979
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• 2023

Due to laws, regulations, privacy, etc., between 70-90 percent of providers do not share medical data, forming a "data island". It is essential to collaborate across multiple institutions without sharing patient data. Most existing methods adopt distributed learning and centralized federal architecture to solve this problem, but there are problems of resource heterogeneity and data heterogeneity in the practical application process. This paper proposes a collaborative deep learning modelling method based on the blockchain network. The training process uses encryption parameters to replace the original remote source data transmission to protect privacy. Hyperledger Fabric blockchain is adopted to realize that the parties are not restricted by the third-party authoritative verification end. To a certain extent, the distrust and single point of failure caused by the centralized system are avoided. The aggregation algorithm uses the FedProx algorithm to solve the problem of device heterogeneity and data heterogeneity. The experiments show that the maximum improvement of segmentation accuracy in the collaborative training mode proposed in this paper is 11.179% compared to local training. In the sequential training mode, the average accuracy improvement is greater than 7%. In the parallel training mode, the average accuracy improvement is greater than 8%. The experimental results show that the model proposed in this paper can solve the current problem of centralized modelling of multicenter data. In particular, it provides ideas to solve privacy protection and break "data silos", and protects all data.

• 한국태양에너지학회 논문집
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• 제33권4호
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• pp.51-58
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• 2013

A study on power performance testing of a wind turbine which has no met-mast at a distance of 2~4 rotor diameter was carried out using the Nacelle Transfer Function, NTF, according to IEC 61400-12-2. The wind data for this study was measured at HanKyoung wind farm of Jeju Island. The NTF was modeled using the correlation between wind speeds from the met-mast and from the wind turbine nacelle within 2~4 rotor diameter from the met-mast. The NTF was verified by the comparison of estimated Annual Energy Productions, AEPs, and binned power curves. The Nacelle Power Curve, NPC, was derived from the nacelle wind speed data corrected by NTF. The NPC of wind turbine under test and the power curve offered by the turbine manufacturer were compared to check whether the wind turbine is properly generating electricity. Overall the NPC was in good agreement with the manufacturer's power curve. The result showed power performance testing for a wind turbine which has no met-mast at a distance of 2~4 rotor diameter was successfully carried out in compliance with IEC 61400-12-2.

• The Plant Pathology Journal
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• 제35권5호
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• pp.498-507
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• 2019

Odontoglossum ringspot virus (ORSV) is a member of the genus Tobamovirus. It is one of the most prevalent viruses infecting orchids worldwide. Earlier studies reported the genetic variability of ORSV isolates from Korea and China. However, the evolutionary rate, timescale, and phylogeographical analyses of ORSV were unclear. Twenty-one coat protein (CP) gene sequences of ORSV were determined in this study, and used them together with 145 CP sequences obtained from GenBank to infer the genetic diversities, evolutionary rate, timescale and migration of ORSV populations. Evolutionary rate of ORSV populations was $1.25{\times}10^{-3}nucleotides/site/y$. The most recent common ancestors came from 30 year ago (95% confidence intervals, 26-40). Based on CP gene, ORSV migrated from mainland China and South Korea to Taiwan island, Germany, Australia, Singapore, and Indonesia, and it also circulated within east Asia. Our study is the first attempt to evaluate the evolutionary rates, timescales and migration dynamics of ORSV.

• 한국해양환경ㆍ에너지학회지
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• 제19권2호
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• pp.137-143
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• 2016

10 MW급 부유식 파력-해상풍력 복합발전 플랫폼의 석션 매립 앵커 시스템 설계를 위하여 제주도 차귀도 서북쪽 인근해역에서 퇴적 환경 및 퇴적물 성분 조사를 수행하였다. Chirp III을 이용하여 획득한 탄성파 단면도를 Chough et al.[2002]의 분류 방법에 따라 음향상 분류를 수행하였다. 그 결과, 조사 해역내의 중앙 및 서북부 지역에서는 주로 편평한 해저면 아래 두께 5~15 m의 내부 반사층이 존재하는 Type I-3으로 확인되었다. 반면 동남부 지역에서는 표층 반사 신호가 상대적으로 큰 Type I-1, I-2 그리고 III-1로 확인되었다. 또한 8개의 대표 정점에서 채취한 시료에 대하여 5종류의 물리적 시험(단위중량, 함수비, 입도분석, 액성 및 소성 한계, 비중)을 수행한 결과 조사 해역 내에는 모래(SP)와 실트가 섞인 모래(SM) 그리고 SP-SM이 혼합된 퇴적물이 존재함을 확인하였다.

• 동양고전연구
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• 제69호
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• pp.147-178
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• 2017

본고는 문집이 남아 있지 않지만 그 행적으로 후대에 많이 알려진 무민공(武愍公) 최형(崔瑩)의 문학에 대해 고찰하고자 시도되었다. 현재 무민공(武愍公)의 문집이 남아 있지 않고, 시조 작품 몇 수만이 그 문학으로 추정되고 있는바, 기존에 이러한 무민공(武愍公)의 문학에 대해 무민공(武愍公)을 둘러싼 설화나, 다른 문인들의 문집에 수록된 제문과 시문 등을 바탕으로, 무민공(武愍公) 주변의 연구 성과는 상당하였다. 그러나 정작 무민공(武愍公) 자신의 문학은 뒷전이 되어 왔다는 데 문제의식을 갖고. 본고에서는 현재 무민공(武愍公)의 언행(言行) 기록과 관련해 찾아볼 수 있는 자료 "고려사(高麗史)"의 세가(世家)와 열전(列傳), 그리고 "고려사절요(高麗史節要)"와 "태조실록(太祖實錄)", "동사강목(東史綱目)", "신증동국여지승람(新增東國輿地勝覽)", "연려실기술(燃藜室記述)" 등에서 무민공(武愍公)의 산문(散文)을 추출해보았다. 이로써 무민공(武愍公) 문학의 일면을 고찰할 수 있었다. 그 결과 무민공(武愍公)의 산문(散文) 작품으로, 신돈(辛旽)의 무고(誣告)로 계림윤(鷄林尹)에 좌천(左遷)되어 토로한 탄식문(歎息文), 제주(濟州) 토벌(討伐)에 나서 나주(羅州)에 당도해 쓴 맹약서(盟約書), 제주목사(濟州牧使) 박윤청(朴允淸)을 설득하려 보낸 서간문(書簡文), 천도(遷都) 반대의 뜻을 밝힌 의론문(議論文)들과, 홍산(鴻山) 전투(戰鬪)에 나서겠다는 뜻의 계문(?文), 강화도(江華道) 패북(敗北)의 참담함 표출과 그 방비(防備) 대책(對策)을 위한 계문(?文), 그리고 우왕(禑王)을 향한 진심어린 간언(諫言) 등을 무민공(武愍公)의 문학으로 새로 발견할 수 있었다. 문집이 남아 있지 않은 상황에서, 이러한 공적 기록에 들어 있는 무민공(武愍公)의 산문(散文) 작품들조차 제대로 조명 받지 못했다는 점을 고려할 때 본고의 시도는 한 의의가 있다고 여겨진다. 이러한 성과를 바탕으로 당대 또는 후대 문인들의 문집에서 무민공(武愍公)의 행적과 관련해 그 인물됨을 역사적으로 평가한 시각에 대해 새롭게 의의를 부여하는 연구가 이어질 수 있기를 기대한다.

• Geomechanics and Engineering
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• 제22권2호
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• pp.173-185
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• 2020

Calcareous soil is originated from marine biogenic sediments and weathering of carbonate rocks. The formation history for calcareous sediment includes complex physical, biological and chemical processes. It is preferably selected as the major fill materials for hydraulic reclamation and artificial island construction. Calcareous sands possess inter pores and complex shape are liable to be damaged at normal working stress level due to its fragile nature. Thus, the engineering properties of calcareous soil are greatly affected by its high compressibility and crushability. A series of triaxial shear tests were performed on calcareous sands derived from South China Sea under different test conditions. The effects of confining pressure, particle size, grading, compactness, drainage condition, and water content on the total amount of particle breakage for calcareous soil were symmetrically investigated. The test results showed that the crushing extent of calcareous sand with full gradation was smaller than that a single particle group under the same test condition. Large grains are cushioned by surrounding small particles and such micro-structure reduces the probability of breakage for well-graded sands. The increasing tendency of particle crushing for calcareous sand with a rise in confining pressure and compactness is confirmed. It is also evident that a rise in water content enhances the amount of particle breakage for calcareous sand. However, varying tendency of particle breakage with grain size is still controversial and requires further examination.

• Nuclear Engineering and Technology
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• 제52권2호
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• pp.417-428
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• 2020

Investigations of the commercial aircraft impact effect on nuclear island infrastructures have been drawing extensive attention, and this paper aims to perform the safety assessment of Generation III nuclear power plant (NPP) buildings subjected to typical commercial aircrafts crash. At present Part III, the local damage of the rigid components of aircraft, e.g., engine and landing gear, impacting the steel concrete (SC) structures of NPP containment is mainly discussed. Two typical SC target panels with the thicknesses of 40 mm and 100 mm, as well as the steel cylindrical projectile with a mass of 2.15 kg and a diameter of 80 mm are fabricated. By using a large-caliber air gas gun, both the projectile penetration and perforation test are conducted, in which the striking velocities were ranged from 96 m/s to 157 m/s. The bulging velocity and the maximal deflection of rear steel plate, as well as penetration depth of projectile are derived, and the local deformation and failure modes of SC panels are assessed experimentally. Then, the commercial finite element program LS-DYNA is utilized to perform the numerical simulations, by comparisons with the experimental and simulated projectile impact process and SC panel damage, the numerical algorithm, constitutive models and the corresponding parameters are verified. The present work can provide helpful references for the evaluation of the local impact resistance of NPP buildings against the aircraft engine.

• Nuclear Engineering and Technology
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• 제52권2호
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• pp.381-396
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• 2020

Investigations of the commercial aircraft impact effect on nuclear island infrastructures have been drawing extensive attention, and this paper aims to perform the safety assessment of Generation III nuclear power plant (NPP) buildings subjected to typical commercial aircrafts crash. At present Part I, finite element (FE) models establishment and validations for both the aircrafts and NPP buildings are performed. (i) Airbus A320 and A380 aircrafts are selected as the representative medium and large commercial aircrafts, and the corresponding fine FE models including the skin, beam, fuel and etc. are established. By comparing the numerically derived impact force time-histories with the existing published literatures, the rationality of aircrafts models is verified. (ii) Fine FE model of the Chinese Zhejiang Sanao NPP buildings is established, including the detailed structures and reinforcing arrangement of both the containment and auxiliary buildings. (iii) By numerically reproducing the existing 1/7.5 scaled aircraft model impact tests on steel plate reinforced concrete (SC) panels and assessing the impact process and velocity time-history of aircraft model, as well as the damage and the maximum deflection of SC panels, the applicability of the existing three concrete constitutive models (i.e., K&C, Winfrith and CSC) are evaluated and the superiority of Winfrith model for SC panels under deformable missile impact is verified. The present work can provide beneficial reference for the integral aircraft crash analyses and structural damage assessment in the following two parts of this paper.

• Nuclear Engineering and Technology
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• 제52권2호
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• pp.397-416
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• 2020

Investigations of the commercial aircraft impact effect on nuclear island infrastructures have been drawing extensive attention, and this paper aims to perform the safety assessment of Generation III nuclear power plant (NPP) buildings subjected to typical commercial aircrafts crash. At present Part II, based on the verified finite element (FE) models of aircrafts Airbus A320 and A380, as well as the NPP containment and auxiliary buildings in Part I of this paper, the whole collision process is reproduced numerically by adopting the coupled missile-target interaction approach with the finite element code LS-DYNA. The impact induced damage of NPP plant under four impact locations of containment (cylinder, air intake, conical roof and PCS water tank) and two impact locations of auxiliary buildings (exterior wall and roof of spent fuel pool room) are evaluated. Furthermore, by considering the inner structures in the containment and raft foundation of NPP, the structural vibration analyses are conducted under two impact locations (middle height of cylinder, main control room in the auxiliary buildings). It indicates that, within the discussed scenarios, NPP structures can withstand the impact of both two aircrafts, while the functionality of internal equipment on higher floors will be affected to some extent under impact induced vibrations, and A380 aircraft will cause more serious structural damage and vibrations than A320 aircraft. The present work can provide helpful references to assess the safety of the structures and inner equipment of NPP plant under commercial aircraft impact.

• Nuclear Engineering and Technology
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• 제54권7호
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• pp.2491-2509
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• 2022

As an important device in the nuclear island, the nuclear coolant pump can continuously provide power for medium circulation. The vane is one of the stationary parts in the nuclear coolant pump, which is installed between the impeller and the casing. The shape of the vane plays a significant role in the pump's overall performance and stability which are the important indicators during the safety serve process. Hence, the bionic concept is firstly applied into the design process of the vane to improve the performance of the nuclear coolant pump. Taking the scaled high-performance hydraulic model (on a scale of 1:2.5) of the coolant pump as the reference, a united bionic design approach is proposed for the unique structure of the guide vane of the nuclear coolant pump. Then, a new optimization design platform is established to output the optimal bionic vane. Finally, the comparative results and the corresponding mechanism are analyzed. The conclusions can be gotten as: (1) four parameters are introduced to configure the shape of the bionic blade, the significance of each parameter is herein demonstrated; (2) the optimal bionic vane is successfully obtained by the optimization design platform, the efficiency performance and the head performance of which can be improved by 1.6% and 1.27% respectively; (3) when compared to the original vane, the optimized bionic vane can improve the inner flow characteristics, namely, it can reduce the flow loss and decrease the pressure pulsation amplitude; (4) through the mechanism analysis, it can be found out that the bionic structure can induce the spanwise velocity and the vortices, which can reduce drag and suppress the boundary layer separation.