首页 > 最新文献

Journal of Korean navigation and port research最新文献

英文 中文
A Data Mining Algorithm to Gaining Customer Loyalty to Ports Based on OD Data for Improving Port Competitiveness 基于OD数据的港口客户忠诚度挖掘算法,提高港口竞争力
Pub Date : 2020-10-31 DOI: 10.5394/KINPR.2020.44.5.391
Qianfeng Lin, J. Son
Every port is competing for attracting loyal customers from other ports to achieve more profits stably. This paper proposes a data-mining scheme to facilitate this process. For resolving the problem, the OD (Origination-Destination) data are gathered from the AIS (Automatic Identification System) data. The OD data are clustered according to the arrival dates and ports. The FP-growth algorithm is applied to mine the frequent patterns of ships arriving at ports. Maintaining a loyal customer list for port updates and accuracy is critical in establishing its usefulness. These lists are critical as they can be used to provide suggestions for new products and services to loyal customers. Finally, based on the frequent patterns of the ships and the mode of arrival times, a formula proposed in this paper to derive shipping companies’ loyalty to ports was applied. The case of Kaohsiung port was shown as an example of our algorithm, and the OD data of ships in 2017-2018 were processed. Using the results of our algorithm, other rival ports, such as Shanghai or Busan, may attract customers no longer loyal to Kaohsiung ports in the last two years and attract them as new loyal customers.
每个港口都在竞相吸引其他港口的忠实客户,以稳定地获得更多的利润。本文提出了一种数据挖掘方案来促进这一过程。为了解决这个问题,从AIS(自动识别系统)数据中收集OD (origin - destination)数据。OD数据根据到货日期和到货端口进行聚类。应用FP-growth算法挖掘船舶到港的频繁模式。为端口更新和准确性维护忠实的客户列表对于建立其有用性至关重要。这些列表是至关重要的,因为它们可以用来为忠实的客户提供新产品和服务的建议。最后,基于船舶的频繁模式和到达时间模式,应用本文提出的公式推导航运公司对港口的忠诚度。以高雄港为例,对2017-2018年的船舶OD数据进行了处理。利用我们的算法结果,其他竞争港口,如上海或釜山,可能会吸引过去两年不再忠诚于高雄港口的客户,并吸引他们成为新的忠诚客户。
{"title":"A Data Mining Algorithm to Gaining Customer Loyalty to Ports Based on OD Data for Improving Port Competitiveness","authors":"Qianfeng Lin, J. Son","doi":"10.5394/KINPR.2020.44.5.391","DOIUrl":"https://doi.org/10.5394/KINPR.2020.44.5.391","url":null,"abstract":"Every port is competing for attracting loyal customers from other ports to achieve more profits stably. This paper proposes a data-mining scheme to facilitate this process. For resolving the problem, the OD (Origination-Destination) data are gathered from the AIS (Automatic Identification System) data. The OD data are clustered according to the arrival dates and ports. The FP-growth algorithm is applied to mine the frequent patterns of ships arriving at ports. Maintaining a loyal customer list for port updates and accuracy is critical in establishing its usefulness. These lists are critical as they can be used to provide suggestions for new products and services to loyal customers. Finally, based on the frequent patterns of the ships and the mode of arrival times, a formula proposed in this paper to derive shipping companies’ loyalty to ports was applied. The case of Kaohsiung port was shown as an example of our algorithm, and the OD data of ships in 2017-2018 were processed. Using the results of our algorithm, other rival ports, such as Shanghai or Busan, may attract customers no longer loyal to Kaohsiung ports in the last two years and attract them as new loyal customers.","PeriodicalId":16242,"journal":{"name":"Journal of Korean navigation and port research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91466335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Design of an RCGA-based Linear Active Disturbance Rejection Controller for Ship Heading Control 基于rcga的船舶航向控制线性自抗扰控制器设计
Pub Date : 2020-10-31 DOI: 10.5394/KINPR.2020.44.5.423
Jong-kap Ahn, Myung-Ok So
A ship’s automatic steering system is the basis for addressing control difficulties related to course-changing and course-keeping during navigation through heading angle control, and is a link in realizing unmanned and autonomous ships. This study proposes a robust RCGA-based linear active disturbance rejection controller (LADRC) design method considering environmental disturbances, measurement noise, and model uncertainties in designing a ship heading controller for use when the ship is sailing. The LADRC consisted of a transient profile, a linear extended state observer, and a PD controller. The control gains in the LADRC with the linear extended state observer were adjusted by RCGAs to minimize the integral of the time-weighted absolute error (ITAE), which is an evaluation function of the control system. The proposed method was applied to ship heading control, and its effectiveness was validated by comparing the propulsive energy loss between the proposed method and a conventional linear PD controller. The simulation results showed that the proposed method had the advantages of lower propulsive energy loss, more robustness, and higher tracking precision than the conventional linear PD controller.
船舶自动操舵系统是通过航向角控制解决船舶航行过程中变航向和保持航向等控制难题的基础,是实现船舶无人驾驶和自主的重要环节。本文提出了一种鲁棒的基于rcga的线性自抗扰控制器(LADRC)设计方法,该方法在设计船舶航行时使用的航向控制器时考虑了环境干扰、测量噪声和模型不确定性。LADRC由一个瞬态轮廓、一个线性扩展状态观测器和一个PD控制器组成。采用线性扩展状态观测器对LADRC的控制增益进行调节,使控制系统的评价函数时间加权绝对误差(ITAE)的积分最小。将该方法应用于船舶航向控制,并与传统线性PD控制器的推进能量损失进行了比较,验证了该方法的有效性。仿真结果表明,与传统线性PD控制器相比,该方法具有推进能量损失小、鲁棒性强、跟踪精度高等优点。
{"title":"Design of an RCGA-based Linear Active Disturbance Rejection Controller for Ship Heading Control","authors":"Jong-kap Ahn, Myung-Ok So","doi":"10.5394/KINPR.2020.44.5.423","DOIUrl":"https://doi.org/10.5394/KINPR.2020.44.5.423","url":null,"abstract":"A ship’s automatic steering system is the basis for addressing control difficulties related to course-changing and course-keeping during navigation through heading angle control, and is a link in realizing unmanned and autonomous ships. This study proposes a robust RCGA-based linear active disturbance rejection controller (LADRC) design method considering environmental disturbances, measurement noise, and model uncertainties in designing a ship heading controller for use when the ship is sailing. The LADRC consisted of a transient profile, a linear extended state observer, and a PD controller. The control gains in the LADRC with the linear extended state observer were adjusted by RCGAs to minimize the integral of the time-weighted absolute error (ITAE), which is an evaluation function of the control system. The proposed method was applied to ship heading control, and its effectiveness was validated by comparing the propulsive energy loss between the proposed method and a conventional linear PD controller. The simulation results showed that the proposed method had the advantages of lower propulsive energy loss, more robustness, and higher tracking precision than the conventional linear PD controller.","PeriodicalId":16242,"journal":{"name":"Journal of Korean navigation and port research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85443539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Design and Assessment of Reliquefaction System According to Boil Off Gas Reliquefaction Rate of Liquefied Hydrogen Carrier 基于液态氢载体汽化气再液化速率的再液化系统设计与评价
Pub Date : 2020-08-01 DOI: 10.5394/KINPR.2020.44.4.283
조 욱래, 이 현용, 류 보림, 강 호근
{"title":"Design and Assessment of Reliquefaction System According to Boil Off Gas Reliquefaction Rate of Liquefied Hydrogen Carrier","authors":"조 욱래, 이 현용, 류 보림, 강 호근","doi":"10.5394/KINPR.2020.44.4.283","DOIUrl":"https://doi.org/10.5394/KINPR.2020.44.4.283","url":null,"abstract":"","PeriodicalId":16242,"journal":{"name":"Journal of Korean navigation and port research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85516686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
The Effect of Sunk Cost and Anchoring Effect on Shipping Finance 沉没成本与锚定效应对航运融资的影响
Pub Date : 2020-08-01 DOI: 10.5394/KINPR.2020.44.4.326
김 우석, 이 기환
{"title":"The Effect of Sunk Cost and Anchoring Effect on Shipping Finance","authors":"김 우석, 이 기환","doi":"10.5394/KINPR.2020.44.4.326","DOIUrl":"https://doi.org/10.5394/KINPR.2020.44.4.326","url":null,"abstract":"","PeriodicalId":16242,"journal":{"name":"Journal of Korean navigation and port research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90157120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
A Study on the Advance Transportation System for Inter Terminal Transshipment: Focused on the Busan New Port 码头间转运超前运输系统研究——以釜山新港为例
Pub Date : 2020-08-01 DOI: 10.5394/KINPR.2020.44.4.298
조 민지, 이 승필, 김 환성
{"title":"A Study on the Advance Transportation System for Inter Terminal Transshipment: Focused on the Busan New Port","authors":"조 민지, 이 승필, 김 환성","doi":"10.5394/KINPR.2020.44.4.298","DOIUrl":"https://doi.org/10.5394/KINPR.2020.44.4.298","url":null,"abstract":"","PeriodicalId":16242,"journal":{"name":"Journal of Korean navigation and port research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79442868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
An Evaluation of Business Performance for Water Transportation Company Groups Using the Integrated Fuzzy AHP-PROMETHEE Method 基于模糊层次分析法的水运企业集团经营绩效评价
Pub Date : 2020-08-01 DOI: 10.5394/KINPR.2020.44.4.319
장 운재
{"title":"An Evaluation of Business Performance for Water Transportation Company Groups Using the Integrated Fuzzy AHP-PROMETHEE Method","authors":"장 운재","doi":"10.5394/KINPR.2020.44.4.319","DOIUrl":"https://doi.org/10.5394/KINPR.2020.44.4.319","url":null,"abstract":"","PeriodicalId":16242,"journal":{"name":"Journal of Korean navigation and port research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89097766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
An Analysis on Development Determinants for Revitalization of Marina Development 浅析码头开发振兴的发展决定因素
Pub Date : 2020-08-01 DOI: 10.5394/KINPR.2020.44.4.312
김 남규, 이 재형
{"title":"An Analysis on Development Determinants for Revitalization of Marina Development","authors":"김 남규, 이 재형","doi":"10.5394/KINPR.2020.44.4.312","DOIUrl":"https://doi.org/10.5394/KINPR.2020.44.4.312","url":null,"abstract":"","PeriodicalId":16242,"journal":{"name":"Journal of Korean navigation and port research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87617730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Development of Environment Friendly Permeable Concrete Bio Blocks 环境友好型透水混凝土生物砌块的研制
Pub Date : 2020-08-01 DOI: 10.5394/KINPR.2020.44.4.305
송 현우, 이 중우, 권 성민, 이 태형, 오 영탁
{"title":"Development of Environment Friendly Permeable Concrete Bio Blocks","authors":"송 현우, 이 중우, 권 성민, 이 태형, 오 영탁","doi":"10.5394/KINPR.2020.44.4.305","DOIUrl":"https://doi.org/10.5394/KINPR.2020.44.4.305","url":null,"abstract":"","PeriodicalId":16242,"journal":{"name":"Journal of Korean navigation and port research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73550567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
A Study on the Measurement and Effect Factors of Productivity of the Korean Ocean Carriers 韩国远洋航运公司生产率测度及影响因素研究
Pub Date : 2020-08-01 DOI: 10.5394/KINPR.2020.44.4.338
Hyung-Sik Nam, Ki-Myung Ahn
In this study, we first measured the Malmquist productivity index by DEA among the Korean ocean carriers. Second, it was intended to present measures to improve productivity by identifying the influence and discriminating power between productivity and the major financial ratios (profitability, financial stability, liquidity, efficiency and value-added productivity). Compared to 2017, there are 11 more shipping carriers with decline in productivity (MPI) than those with an increase in 2018. The increase in productivity is attributed to an increase in the Technology Change Index (TCI) affected by the external environment. There is strong significant correlation between the productivity (MPI) and the management efficiency (CRS). Additionally, the TECI (TECHI) index of the technological efficiency changes from internal factors of the shipping carrier is significantly higher than that of the efficient shipping carrier. This is because of the differences in scale efficiency. The ratio of charter cost/sales is also lower than that of the carriers with high productivity (0.17) and with low productivity (0.21). With 7% of the shipping carrier with MPI>1, only 1% of MPI <1 is found to have a significant impact on its productivity.
在本研究中,我们首先用DEA测量了韩国海运承运人的Malmquist生产率指数。第二,它旨在通过确定生产率与主要财务比率(盈利能力、金融稳定性、流动性、效率和增值生产率)之间的影响和区别能力,提出提高生产率的措施。与2017年相比,生产力下降(MPI)的航运公司比2018年增加了11家。生产率的提高归因于受外部环境影响的技术变革指数(TCI)的增加。生产效率(MPI)与管理效率(CRS)之间存在很强的显著相关。此外,航运公司内部因素引起的技术效率变化的TECI (TECHI)指数显著高于高效航运公司。这是因为规模效率的差异。包机成本/销售比也低于生产率高的航空公司(0.17)和生产率低的航空公司(0.21)。在7%的MPI>1的航运公司中,只有1%的MPI <1对其生产率有显著影响。
{"title":"A Study on the Measurement and Effect Factors of Productivity of the Korean Ocean Carriers","authors":"Hyung-Sik Nam, Ki-Myung Ahn","doi":"10.5394/KINPR.2020.44.4.338","DOIUrl":"https://doi.org/10.5394/KINPR.2020.44.4.338","url":null,"abstract":"In this study, we first measured the Malmquist productivity index by DEA among the Korean ocean carriers. Second, it was intended to present measures to improve productivity by identifying the influence and discriminating power between productivity and the major financial ratios (profitability, financial stability, liquidity, efficiency and value-added productivity). Compared to 2017, there are 11 more shipping carriers with decline in productivity (MPI) than those with an increase in 2018. The increase in productivity is attributed to an increase in the Technology Change Index (TCI) affected by the external environment. There is strong significant correlation between the productivity (MPI) and the management efficiency (CRS). Additionally, the TECI (TECHI) index of the technological efficiency changes from internal factors of the shipping carrier is significantly higher than that of the efficient shipping carrier. This is because of the differences in scale efficiency. The ratio of charter cost/sales is also lower than that of the carriers with high productivity (0.17) and with low productivity (0.21). With 7% of the shipping carrier with MPI>1, only 1% of MPI <1 is found to have a significant impact on its productivity.","PeriodicalId":16242,"journal":{"name":"Journal of Korean navigation and port research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74206498","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
A Study on Estimating the Appropriate Fee of Aids to Navigation Service for the Pyeongtaek Regional Office of Oceans and Fisheries “平泽地方海洋水产厅导航辅助服务费用的合理计算研究
Pub Date : 2020-08-01 DOI: 10.5394/KINPR.2020.44.4.347
문 범식, 전 기준, 김 태균
{"title":"A Study on Estimating the Appropriate Fee of Aids to Navigation Service for the Pyeongtaek Regional Office of Oceans and Fisheries","authors":"문 범식, 전 기준, 김 태균","doi":"10.5394/KINPR.2020.44.4.347","DOIUrl":"https://doi.org/10.5394/KINPR.2020.44.4.347","url":null,"abstract":"","PeriodicalId":16242,"journal":{"name":"Journal of Korean navigation and port research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74912851","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
期刊
Journal of Korean navigation and port research
全部 Acc. Chem. Res. ACS Applied Bio Materials ACS Appl. Electron. Mater. ACS Appl. Energy Mater. ACS Appl. Mater. Interfaces ACS Appl. Nano Mater. ACS Appl. Polym. Mater. ACS BIOMATER-SCI ENG ACS Catal. ACS Cent. Sci. ACS Chem. Biol. ACS Chemical Health & Safety ACS Chem. Neurosci. ACS Comb. Sci. ACS Earth Space Chem. ACS Energy Lett. ACS Infect. Dis. ACS Macro Lett. ACS Mater. Lett. ACS Med. Chem. Lett. ACS Nano ACS Omega ACS Photonics ACS Sens. ACS Sustainable Chem. Eng. ACS Synth. Biol. Anal. Chem. BIOCHEMISTRY-US Bioconjugate Chem. BIOMACROMOLECULES Chem. Res. Toxicol. Chem. Rev. Chem. Mater. CRYST GROWTH DES ENERG FUEL Environ. Sci. Technol. Environ. Sci. Technol. Lett. Eur. J. Inorg. Chem. IND ENG CHEM RES Inorg. Chem. J. Agric. Food. Chem. J. Chem. Eng. Data J. Chem. Educ. J. Chem. Inf. Model. J. Chem. Theory Comput. J. Med. Chem. J. Nat. Prod. J PROTEOME RES J. Am. Chem. Soc. LANGMUIR MACROMOLECULES Mol. Pharmaceutics Nano Lett. Org. Lett. ORG PROCESS RES DEV ORGANOMETALLICS J. Org. Chem. J. Phys. Chem. J. Phys. Chem. A J. Phys. Chem. B J. Phys. Chem. C J. Phys. Chem. Lett. Analyst Anal. Methods Biomater. Sci. Catal. Sci. Technol. Chem. Commun. Chem. Soc. Rev. CHEM EDUC RES PRACT CRYSTENGCOMM Dalton Trans. Energy Environ. Sci. ENVIRON SCI-NANO ENVIRON SCI-PROC IMP ENVIRON SCI-WAT RES Faraday Discuss. Food Funct. Green Chem. Inorg. Chem. Front. Integr. Biol. J. Anal. At. Spectrom. J. Mater. Chem. A J. Mater. Chem. B J. Mater. Chem. C Lab Chip Mater. Chem. Front. Mater. Horiz. MEDCHEMCOMM Metallomics Mol. Biosyst. Mol. Syst. Des. Eng. Nanoscale Nanoscale Horiz. Nat. Prod. Rep. New J. Chem. Org. Biomol. Chem. Org. Chem. Front. PHOTOCH PHOTOBIO SCI PCCP Polym. Chem.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
0
微信
客服QQ
Book学术公众号 扫码关注我们
反馈
×
意见反馈
请填写您的意见或建议
请填写您的手机或邮箱
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
Book学术官方微信
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术
文献互助 智能选刊 最新文献 互助须知 联系我们:info@booksci.cn
Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。
Copyright © 2023 Book学术 All rights reserved.
ghs 京公网安备 11010802042870号 京ICP备2023020795号-1