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Nonprofit · Tokyo · Japan

ClassNK

In research, ClassNK stands highest in Engineering (#7,624 of 9,532 worldwide) and Physical Sciences (#14,890 of 17,446 worldwide), over all time.

classnk.or.jp/hp/ja/index.htmlROR OpenAlex
World rank, all time
#24,932
of 34,923
Rank in Japan
#910
of 1,923
Research works
379
▲ 16% vs 2018-21
Citations
2.7k
7.0 per fractional work
Top-10% rate
8.7%
all institutions 10.0%
vs its own fields
0.67×
1.00× is exactly expected
Open access
39%
world 40%
International
14%
world 18%
ClassNK

What is ClassNK known for in research?

The fields where it stands highest, over all time, ranked among every institution above the floor in each field.

FieldWorld rankWhere that sitsTop-10% rateWorks
EngineeringField #7,624 of 9,532 5.7%192
Physical SciencesDomain #14,890 of 17,446 6.6%285

Each strip is that field's whole ranked pool, with the notch where ClassNK sits in it, in the colour of the band that rank falls in. The track under the rate is the rate itself: it carries no average mark, because the average differs by field (from about 6% in Dentistry to 21% in Economics).

Which fields of science does ClassNK work in?

In 2022-now, 61% of research at ClassNK is in Physical Sciences, 26% in Social Sciences. Its largest fields are Engineering (37%), Social Sciences (16%), Earth and Planetary Sciences (7%). It does 1.5× the world's share of Physical Sciences.

Physical Sciences: 43 fractional works · 60.6% of its workEngineering: 26 fractional works · 37.0% of its workOcean Engineering: 5 fractional works · 7.4% of its workMechanical Engineering: 5 fractional works · 6.7% of its workCivil and Structural Engineering: 4 fractional works · 6.3% of its workMechanics of Materials: 4 fractional works · 5.4% of its workComputational Mechanics: 3 fractional works · 4.1% of its workAerospace Engineering: 1 fractional works · 1.5% of its workControl and Systems Engineering: 1 fractional works · 1.5% of its workBuilding and Construction: 1 fractional works · 1.4% of its workAutomotive Engineering: 1 fractional works · 0.9% of its workIndustrial and Manufacturing Engineering: 0 fractional works · 0.5% of its workElectrical and Electronic Engineering: 0 fractional works · 0.5% of its workSafety, Risk, Reliability and Quality: 0 fractional works · 0.5% of its workBiomedical Engineering: 0 fractional works · 0.4% of its workEarth and Planetary Sciences: 5 fractional works · 7.3% of its workOceanography: 3 fractional works · 4.2% of its workAtmospheric Science: 2 fractional works · 2.1% of its workGeochemistry and Petrology: 0 fractional works · 0.3% of its workEarth-Surface Processes: 0 fractional works · 0.2% of its workGeology: 0 fractional works · 0.2% of its workGeophysics: 0 fractional works · 0.2% of its workComputer Science: 4 fractional works · 6.1% of its workArtificial Intelligence: 2 fractional works · 2.4% of its workInformation Systems: 2 fractional works · 2.1% of its workComputer Vision and Pattern Recognition: 1 fractional works · 0.9% of its workComputational Theory and Mathematics: 0 fractional works · 0.7% of its workEnvironmental Science: 4 fractional works · 6.0% of its workEnvironmental Engineering: 2 fractional works · 2.8% of its workEcology: 1 fractional works · 2.0% of its workPollution: 0 fractional works · 0.5% of its workWater Science and Technology: 0 fractional works · 0.3% of its workSmaller subfields together: 0 fractional works · 0.5% of its workMaterials Science: 2 fractional works · 2.3% of its workMaterials Chemistry: 1 fractional works · 1.7% of its workMetals and Alloys: 0 fractional works · 0.3% of its workGeneral Materials Science: 0 fractional works · 0.2% of its workSmaller subfields together: 0 fractional works · 0.1% of its workMathematics: 1 fractional works · 1.2% of its workApplied Mathematics: 1 fractional works · 1.2% of its workChemical Engineering: 0 fractional works · 0.5% of its workFluid Flow and Transfer Processes: 0 fractional works · 0.5% of its workChemistry: 0 fractional works · 0.1% of its workSocial Sciences: 19 fractional works · 26.1% of its workSocial Sciences: 11 fractional works · 15.6% of its workEducation: 8 fractional works · 10.6% of its workSociology and Political Science: 2 fractional works · 2.3% of its workPolitical Science and International Relations: 1 fractional works · 1.9% of its workLaw: 0 fractional works · 0.6% of its workSmaller subfields together: 0 fractional works · 0.3% of its workEconomics, Econometrics and Finance: 4 fractional works · 5.3% of its workEconomics and Econometrics: 4 fractional works · 5.3% of its workArts and Humanities: 2 fractional works · 2.5% of its workHistory: 0 fractional works · 0.5% of its workLanguage and Linguistics: 0 fractional works · 0.5% of its workMuseology: 0 fractional works · 0.5% of its workPhilosophy: 0 fractional works · 0.5% of its workHistory and Philosophy of Science: 0 fractional works · 0.4% of its workReligious studies: 0 fractional works · 0.2% of its workBusiness, Management and Accounting: 1 fractional works · 0.9% of its workStrategy and Management: 0 fractional works · 0.7% of its workManagement of Technology and Innovation: 0 fractional works · 0.2% of its workDecision Sciences: 1 fractional works · 0.9% of its workStatistics, Probability and Uncertainty: 1 fractional works · 0.9% of its workPsychology: 1 fractional works · 0.9% of its workDevelopmental and Educational Psychology: 0 fractional works · 0.5% of its workSocial Psychology: 0 fractional works · 0.4% of its workHealth Sciences: 6 fractional works · 7.9% of its workMedicine: 4 fractional works · 5.6% of its workInfectious Diseases: 1 fractional works · 1.4% of its workReproductive Medicine: 1 fractional works · 1.1% of its workEpidemiology: 1 fractional works · 0.9% of its workEndocrinology, Diabetes and Metabolism: 0 fractional works · 0.6% of its workPublic Health, Environmental and Occupational Health: 0 fractional works · 0.6% of its workPulmonary and Respiratory Medicine: 0 fractional works · 0.4% of its workNephrology: 0 fractional works · 0.3% of its workCardiology and Cardiovascular Medicine: 0 fractional works · 0.2% of its workSmaller subfields together: 0 fractional works · 0.0% of its workHealth Professions: 2 fractional works · 2.2% of its workHealth Information Management: 1 fractional works · 1.4% of its workGeneral Health Professions: 0 fractional works · 0.4% of its workRadiological and Ultrasound Technology: 0 fractional works · 0.2% of its workSmaller subfields together: 0 fractional works · 0.2% of its workNursing: 0 fractional works · 0.2% of its workLife Sciences: 4 fractional works · 5.3% of its workAgricultural and Biological Sciences: 3 fractional works · 3.9% of its workAquatic Science: 2 fractional works · 2.8% of its workGeneral Agricultural and Biological Sciences: 0 fractional works · 0.5% of its workAnimal Science and Zoology: 0 fractional works · 0.3% of its workSmaller subfields together: 0 fractional works · 0.3% of its workImmunology and Microbiology: 0 fractional works · 0.6% of its workImmunology: 0 fractional works · 0.3% of its workParasitology: 0 fractional works · 0.2% of its workBiochemistry, Genetics and Molecular Biology: 0 fractional works · 0.5% of its workMolecular Biology: 0 fractional works · 0.3% of its workSmaller subfields together: 0 fractional works · 0.2% of its workPharmacology, Toxicology and Pharmaceutics: 0 fractional works · 0.5% of its workPharmacology: 0 fractional works · 0.5% of its workALL ITS WORKClassNK71fractional works, 2022-now
Life Sciences5%Physical Sciences61%Health Sciences8%Social Sciences26%

Each ring splits the one inside it: the four domains of science, their fields, their subfields. Size is fractional works in 2022-now. Every slice is a page; the interactive view zooms down to single topics and colours each by how much more of it this institution does than the world.

Its 4 domains and 21 fields, with their numbers
    1. Engineering2637.0%
    2. Earth and Planetary Sciences57.3%
    3. Computer Science46.1%
    4. Environmental Science46.0%
    5. Materials Science22.3%
    6. Mathematics11.2%
    7. Chemical Engineering00.5%
    8. Chemistry00.1%
    1. Social Sciences1115.6%
    2. Economics, Econometrics and Finance45.3%
    3. Arts and Humanities22.5%
    4. Business, Management and Accounting10.9%
    5. Decision Sciences10.9%
    6. Psychology10.9%
    1. Medicine45.6%
    2. Health Professions22.2%
    3. Nursing00.2%
    1. Agricultural and Biological Sciences33.9%
    2. Immunology and Microbiology00.6%
    3. Biochemistry, Genetics and Molecular Biology00.5%
    4. Pharmacology, Toxicology and Pharmaceutics00.5%
All of science, and how each field's share has moved since 1950: the Science domain explorer

Field profile

Location quotient across every field it publishes in: outside the ring is more than an institution of this size would be expected to publish, inside it is less.

Agricultural and Biological Sciences: 0.81× its world share, 3 worksAgricultural and Bio…Biochemistry, Genetics and Molecular Biology: 0.09× its world share, 0 worksBiochemistry, Geneti…Immunology and Microbiology: 0.54× its world share, 0 worksImmunology and Micro…Pharmacology, Toxicology and Pharmaceutics: 1.33× its world share, 0 worksPharmacology, Toxico…Chemical Engineering: 1.34× its world share, 0 worksChemical EngineeringChemistry: 0.05× its world share, 0 worksChemistryComputer Science: 0.79× its world share, 4 worksComputer ScienceEarth and Planetary Sciences: 4.69× its world share, 5 worksEarth and Planetary …Engineering: 2.47× its world share, 26 worksEngineeringEnvironmental Science: 1.22× its world share, 4 worksEnvironmental ScienceMaterials Science: 0.67× its world share, 2 worksMaterials ScienceMathematics: 1.00× its world share, 1 worksMathematicsHealth Professions: 0.82× its world share, 2 worksHealth ProfessionsMedicine: 0.29× its world share, 4 worksMedicineNursing: 0.32× its world share, 0 worksNursingArts and Humanities: 0.85× its world share, 2 worksArts and HumanitiesBusiness, Management and Accounting: 0.29× its world share, 1 worksBusiness, Management…Decision Sciences: 0.95× its world share, 1 worksDecision SciencesEconomics, Econometrics and Finance: 2.49× its world share, 4 worksEconomics, Econometr…Psychology: 0.28× its world share, 1 worksPsychologySocial Sciences: 1.24× its world share, 11 worksSocial Sciences1×world share
more than its size predictsabout as predictedless

Rings at 0.5×, 1× and 2×. Widest outward: Earth and Planetary Sciences, 4.7×. Every wedge is a field page.

All 21 fields, with their numbers
  1. Earth and Planetary Sciences4.69×5 works
  2. Economics, Econometrics and Finance2.49×4 works
  3. Engineering2.47×26 works
  4. Chemical Engineering1.34×0 works
  5. Pharmacology, Toxicology and Pharmaceutics1.33×0 works
  6. Social Sciences1.24×11 works
  7. Environmental Science1.22×4 works
  8. Mathematics1.00×1 works
  9. Decision Sciences0.95×1 works
  10. Arts and Humanities0.85×2 works
  11. Health Professions0.82×2 works
  12. Agricultural and Biological Sciences0.81×3 works
  13. Computer Science0.79×4 works
  14. Materials Science0.67×2 works
  15. Immunology and Microbiology0.54×0 works
  16. Nursing0.32×0 works
  17. Medicine0.29×4 works
  18. Business, Management and Accounting0.29×1 works
  19. Psychology0.28×1 works
  20. Biochemistry, Genetics and Molecular Biology0.09×0 works
  21. Chemistry0.05×0 works

Who are the top researchers at ClassNK?

Ranked on the quality score, Sho Oh, Tatsuro Nakai and Rei Miratsu lead among researchers whose main affiliation is ClassNK.

  1. 1 Sho Oh Japan · #2,699,211 worldwide 728 citations · 28 works
  2. 2 Tatsuro Nakai Japan · #2,873,750 worldwide 739 citations · 52 works
  3. 3 Rei Miratsu Japan · #3,381,350 worldwide 106 citations · 19 works
  4. 4 Hisao Matsushita Japan · #3,934,904 worldwide 761 citations · 74 works
  5. 5 Tingyao Zhu Japan · #3,939,312 worldwide 488 citations · 61 works
  6. 6 Tomohiro Sugimoto Japan · #3,970,976 worldwide 83 citations · 20 works
  7. 7 Ryuji Miyake Japan · #4,027,420 worldwide 160 citations · 27 works
  8. 8 Toshiro Koiwa Japan · #4,191,431 worldwide 38 citations · 17 works
  9. 9 Motonori Matsuo Japan · #4,353,367 worldwide 0 citations · 16 works
  10. 10 Yoshiro Masuda Japan · #4,668,094 worldwide 12 citations · 16 works
All ranked researchers at ClassNK

What are the most cited papers from ClassNK?

The most cited paper from ClassNK is "Effect of pitting corrosion on local strength of hold frames of bulk carriers (1st report)" (Tatsuro Nakai, Hisao Matsushita, Norio Yamamoto et al., 2004), with 256 citations. Next come "A Study on the Degradation of Coating and Corrosion of Ship’s Hull Based on the Probabilistic Approach" (180) and "Effect of pitting corrosion on local strength of hold frames of bulk carriers (2nd Report)—Lateral-distortional buckling and local face buckling" (136).

Most cited papers
#PaperReleasedCitations
1 Effect of pitting corrosion on local strength of hold frames of bulk carriers (1st report) Tatsuro Nakai, Hisao Matsushita, Norio Yamamoto et al. · Marine Structures Sep 2004 256
2 A Study on the Degradation of Coating and Corrosion of Ship’s Hull Based on the Probabilistic Approach Norio Yamamoto, K. Ikegami · Journal of Offshore Mechanics and Arctic Engineering Aug 1998 180
3 Effect of pitting corrosion on local strength of hold frames of bulk carriers (2nd Report)—Lateral-distortional buckling and local face buckling Tatsuro Nakai, Hisao Matsushita, Norio Yamamoto · Marine Structures Dec 2004 136
4 Estimation of ultimate strength of continuous stiffened panel under combined transverse thrust and lateral pressure Part 2: Continuous stiffened panel Masahiko Fujikubo, Minoru Harada, Tetsuya Yao et al. · Marine Structures Jul 2005 122
5 Effect of pitting corrosion on the ultimate strength of steel plates subjected to in-plane compression and bending Tatsuro Nakai, Hisao Matsushita, Norio Yamamoto · Journal of Marine Science and Technology 23 Mar 2006 121
All 60 most cited papers, with filters and sorting

Which keywords describe research at ClassNK?

By fractional works in 2022-now, weighted toward what it does more of than the world: Pedagogy, Teaching Methods, Corrosion, Finite Element Analysis, Numerical Simulation, Climate Change Impact, Pitting Corrosion and Pipeline.

▲ more of its work than of the world's◆ about the world's share▼ less than the world's

Size is fractional works in 2022-now in the topics tagged with each word; colour is the word's share of this institution's work against its share of the world's. The 40 words are chosen for being large and distinctive. Each links to the topic it comes from most.

All 40 words, with their numbers
  1. Pedagogy5▲ 14×1 topic
  2. Teaching Methods5▲ 44×1 topic
  3. Corrosion4▲ 40×3 topics
  4. Finite Element Analysis4▲ 22×4 topics
  5. Numerical Simulation4▲ 17×5 topics
  6. Sustainability4▲ 2.0×5 topics
  7. Renewable Energy3▲ 3.4×5 topics
  8. Climate Change3▲ 1.68×7 topics
  9. Climate Change Impact3▲ 17×2 topics
  10. Environmental Impact3▲ 2.3×8 topics
  11. Pipeline3▲ 37×2 topics
  12. Pitting Corrosion3▲ 74×2 topics
  13. Steel Structures3▲ 93×2 topics
  14. Tropical Cyclones3▲ 65×2 topics
  15. Fluid-Structure Interaction3▲ 24×3 topics
  16. Risk Analysis3▲ 36×2 topics
  17. CFD Simulations2▲ 254×1 topic
  18. Offshore2▲ 193×1 topic
  19. Reliability Assessment2▲ 82×1 topic
  20. Ship Maneuvering2▲ 254×1 topic
  21. Economic Development2▲ 4.0×2 topics
  22. Maritime Transportation2▲ 59×2 topics
  23. SPH Method2▲ 115×1 topic
  24. Smoothed Particle Hydrodynamics2▲ 115×1 topic
  25. Industrial Enterprises2▲ 90×1 topic
  26. Innovation Economics2▲ 90×1 topic
  27. Risk Assessment2▲ 4.7×4 topics
  28. Irrigation2▲ 146×1 topic
  29. Water Efficiency2▲ 146×1 topic
  30. Wave Modeling2▲ 54×2 topics
  31. Shipping2▲ 56×2 topics
  32. Air Quality2▲ 13×2 topics
  33. Fatigue Crack Closure2▲ 90×1 topic
  34. Fracture Toughness Testing2▲ 90×1 topic
  35. International Relations2▲ 11×2 topics
  36. Ocean Waves2▲ 111×1 topic
  37. Wind Stress2▲ 111×1 topic
  38. Collision Avoidance2▲ 11×2 topics
  39. Human Factors2▲ 26×2 topics
  40. Data Assimilation1▲ 12×2 topics

Which research topics does ClassNK publish most on?

By volume in 2022-now: Education, Innovation and Language Studies, Ship Hydrodynamics and Maneuverability, Structural Integrity and Reliability Analysis and Fluid Dynamics Simulations and Interactions.

Education, Innovation an…5Education, Innovation and Language Studies: 5 fractional worksShip Hydrodynamics and Maneuverability: 2 fractional worksStructural Integrity and…2Structural Integrity and Reliability Analysis: 2 fractional worksFluid Dynamics Simulatio…2Fluid Dynamics Simulations and Interactions: 2 fractional worksEconomic and Industrial Development: 2 fractional worksEngineering and Agricultural Innovations: 2 fractional worksFatigue and fracture mec…2Fatigue and fracture mechanics: 2 fractional worksOcean Waves and Remote Sensing: 2 fractional worksEducational Methods and Media Use: 1 fractional worksMaritime Navigation and Safety: 1 fractional works
EducationOcean EngineeringMechanical EngineeringComputational Mechanics5 others

Area is fractional works; colour is the subfield each topic belongs to.

  1. 1 Education, Innovation and Language Studies Education 5 works
  2. 2 Ship Hydrodynamics and Maneuverability Ocean Engineering 2 works
  3. 3 Structural Integrity and Reliability Analysis Mechanical Engineering 2 works
  4. 4 Fluid Dynamics Simulations and Interactions Computational Mechanics 2 works
  5. 5 Economic and Industrial Development Economics and Econometrics 2 works
  6. 6 Engineering and Agricultural Innovations Aquatic Science 2 works
  7. 7 Fatigue and fracture mechanics Mechanics of Materials 2 works
  8. 8 Ocean Waves and Remote Sensing Oceanography 2 works
  9. 9 Educational Methods and Media Use Information Systems 1 works
  10. 10 Maritime Navigation and Safety Ocean Engineering 1 works

How open and international is its research?

Against the world's own shares: the tick on each track. Both are shares of its output, so they sit on one scale and can be read against each other as well as against the world.

openly available38.7%not open61.3%

World: 40% of research is openly available.

with international co-authors14.1%domestic only85.9%

World: 18% is written across borders.

How has ClassNK's research output changed?

Output in 2022-2025 was 16% higher than in 2018-2021.

still counting1990200020102020
grewheldshrank

The same series as a ribbon: one cell per year, darker for more. The line above answers how much; this answers when.

Its share of all research

Growing output can still be a shrinking share: all of science grows. This is ClassNK as a percentage of every work published that year, 0.00026% in 2024.

still counting0.00050%0.0010%0.0015%ClassNK0.00028% in 202519801990200020102020

Fractional works of ClassNK over all fractional works that year. How the balance of science has shifted.

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ClassNK on Science Explorer

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