1. PhD_TransLog_CI_Pro_Dis_020805 Research Initial Proposal Gerard Ibarra February 04, 2005 Research Initial Proposal Gerard Ibarra February 04, 2005 Update 3.0

2. A Systems Engineering Approach for analyzing the Performance of a City’s Transportation Critical Infrastructure Network Applying Mathematical Modeling to Geographical Interdependencies of the Transportation Network

3. PhD_TransLog_CI_Pro_Dis_020805 A Systems Engineering Approach for analyzing the Performance of a City’s Transportation Critical Infrastructure Network: Applying Mathematical Modeling to Geographical Interdependencies of the Transportation Network A Systems Engineering Approach for analyzing the Performance of a City’s Transportation Critical Infrastructure Network: Applying Mathematical Modeling to Geographical Interdependencies of the Transportation Network Title

4. PhD_TransLog_CI_Pro_Dis_020805 Outline Objective (Requirement) Key Words Definitions Model Systems Engineering (SE) Overview Critical Infrastructure (CI) Overview Transportation & Logistics (Trans/Log) Overview Objective (Requirement) Key Words Definitions Model Systems Engineering (SE) Overview Critical Infrastructure (CI) Overview Transportation & Logistics (Trans/Log) Overview

5. PhD_TransLog_CI_Pro_Dis_020805 Outline Formulating the Model Model Intricacies Metrics and Validation Benefits Conclusion Formulating the Model Model Intricacies Metrics and Validation Benefits Conclusion

6. PhD_TransLog_CI_Pro_Dis_020805 Objective To develop a mathematical model based on system engineering methodologies and practices for assessing the transportation critical infrastructure (CI) of urban cities as a complex system-of-systems with respect to system performance for various types of disconnects encountered by the highway’s network

7. PhD_TransLog_CI_Pro_Dis_020805 Objective

8. PhD_TransLog_CI_Pro_Dis_020805 Key Words Critical Infrastructure Transportation Network System-of-Systems Disconnect Geographical Interdependencies Hierarchical Holographic Modeling Critical Infrastructure Transportation Network System-of-Systems Disconnect Geographical Interdependencies Hierarchical Holographic Modeling

9. PhD_TransLog_CI_Pro_Dis_020805 Key Words Temporal Range Coupling Modal Temporal Range Coupling Modal

10. PhD_TransLog_CI_Pro_Dis_020805 Definitions 1. Critical Infrastructure: a) those systems that if interrupted, derogated, or disconnected would have a significant impact in 1) US Citizens’ way of life and 2) how corporations conduct business

11. PhD_TransLog_CI_Pro_Dis_020805 Definitions b) the thirteen infrastructures defined by the Department of Homeland Security (DHS) as critical to US’s interest based on the Presidential Decision Directive 63 (PDD 63)

12. PhD_TransLog_CI_Pro_Dis_020805 Definitions 1. Transportation Network: a) the highway system of a city b) that which consists of major highways within the Primary Metropolitan Statistical Area (PMSA) of a city that links various sections of the city, handles large volumes of traffic, and for the most part contains intersections transverse by bridges

13. PhD_TransLog_CI_Pro_Dis_020805 Definitions c) interstate, tolls, and highways that have no traffic lights, a minimum speed of 45 mile per hour, and where opposite traffic flow lanes are for the most part divided by concrete or similar barriers

14. PhD_TransLog_CI_Pro_Dis_020805 Definitions 1. System of Systems: sub systems that could act alone as a system and when aggregated with other sub systems, produce an overall system

15. PhD_TransLog_CI_Pro_Dis_020805 Definitions 1. Disconnect: that which pertains to the degradation of the highway’s network through some type of interference, such as weather, accidents, construction, terrorist threats, or some unforeseen catastrophes, that ultimately reduces system performance in the network

16. PhD_TransLog_CI_Pro_Dis_020805 Definitions 2. Disconnect: a) that which involves the reduction of traffic lanes in the highway network, to closing the network for hours, up to reconstructing of the network b) disruption in the flow of traffic in the network

17. PhD_TransLog_CI_Pro_Dis_020805 Definitions 1. Geographical Interdependencies: Interdependencies that are geographically located in proximity to critical infrastructures

18. PhD_TransLog_CI_Pro_Dis_020805 Definitions 1. Hierarchical Holographic Modeling (HHM): a) an approach that allows the user to identify all risks in a system such that the risks are either joint or disjoint b) that approach which seeks mainly to identify risk scenarios rather than to qualify them

19. PhD_TransLog_CI_Pro_Dis_020805 Definitions 1. Temporal Range: the time of the incident 1. Coupling: the linearity and complexity of the interactions 1. Modal: the different type of vehicles including pipeline for the transportation of goods 1. Temporal Range: the time of the incident 1. Coupling: the linearity and complexity of the interactions 1. Modal: the different type of vehicles including pipeline for the transportation of goods

20. PhD_TransLog_CI_Pro_Dis_020805 Definitions 1. Intemodal: Those issues or activities which involve or affect more than one mode of transportation, including transportation connections, choices, cooperation and coordination of various modes. Also known as "multimodal". (transweb.sjsu.edu/comglos2.htm)

21. PhD_TransLog_CI_Pro_Dis_020805 Definitions 1. Steady State: a) normal traffic flow conditions exhibited throughout a 24 – hour period b) the state where traffic patterns and flow are Poisson distributed in defined time intervals given the conditions of the time intervals follow that of a typical day

22. PhD_TransLog_CI_Pro_Dis_020805 Definitions 1. City: “an inhabited place of greater size, population, or importance than a town or village” (Merriam-Webster Online Dictionary)

23. PhD_TransLog_CI_Pro_Dis_020805 Model

24. PhD_TransLog_CI_Pro_Dis_020805 Requirements Model shall provide a ranking of the transportation networks’ links and nodes based on defined performance parameters Model shall be adaptive such that the input states could change Model shall provide a ranking of the transportation networks’ links and nodes based on defined performance parameters Model shall be adaptive such that the input states could change

25. PhD_TransLog_CI_Pro_Dis_020805 Requirements Model shall help the emergency responders and or City government users in the decision making process for resource allocation

26. PhD_TransLog_CI_Pro_Dis_020805 Model Constraints Transportation Highway Network Major US Cities Steady State Exhibited Geographical Interdependencies located within ¼ mile of the network Transportation Highway Network Major US Cities Steady State Exhibited Geographical Interdependencies located within ¼ mile of the network

27. PhD_TransLog_CI_Pro_Dis_020805 Resources Computer System Microsoft Excel Computer System Microsoft Excel

28. PhD_TransLog_CI_Pro_Dis_020805 System Output Two sets of outputs: Preliminary Output 1. Estimated Cost 2. Estimated Risk 3. Estimated Throughput Final Output 1. Network Performance Two sets of outputs: Preliminary Output 1. Estimated Cost 2. Estimated Risk 3. Estimated Throughput Final Output 1. Network Performance

29. PhD_TransLog_CI_Pro_Dis_020805 System Input Any combination of the following items: Type of Disconnect 1. Accident 2. Natural Disaster 3. Terror 4. Other Any combination of the following items: Type of Disconnect 1. Accident 2. Natural Disaster 3. Terror 4. Other Time of Day 1. AM Rush 2. PM Rush 3. Other Day of Week 1. Mon. – Sun. 2. Holiday Time of Day 1. AM Rush 2. PM Rush 3. Other Day of Week 1. Mon. – Sun. 2. Holiday

30. PhD_TransLog_CI_Pro_Dis_020805 Systems Engineering (SE) Overview

31. PhD_TransLog_CI_Pro_Dis_020805 SE Definition “Systems Engineering is an interdisciplinary approach and means to enable the realization of successful systems. It focuses on defining customer needs and required functionality early in the development cycle, documenting requirements, then proceeding with design synthesis and system validation while considering the

32. PhD_TransLog_CI_Pro_Dis_020805 SE Definition complete problem:” 1 Operations Cost & Schedule Performance Training & Support Test Disposal Manufacturing complete problem:” 1 Operations Cost & Schedule Performance Training & Support Test Disposal Manufacturing

33. PhD_TransLog_CI_Pro_Dis_020805 Other SE Components System-of-Systems Interdependencies Elements of a System 2 Components Attributes Relationships System-of-Systems Interdependencies Elements of a System 2 Components Attributes Relationships

34. PhD_TransLog_CI_Pro_Dis_020805 SE Description Top-down/Bottom- up Life-cycle Identification of System Requirements Team Approach

35. PhD_TransLog_CI_Pro_Dis_020805 Critical Infrastructure (CI) Overview

36. PhD_TransLog_CI_Pro_Dis_020805 CI History President's Commission on Critical Infrastructure Protection report called for a national effort to assure the security of the United States' increasingly vulnerable and interconnected infrastructures 3 Lead to the Presidential Decision Directive 63 (PDD63) President's Commission on Critical Infrastructure Protection report called for a national effort to assure the security of the United States' increasingly vulnerable and interconnected infrastructures 3 Lead to the Presidential Decision Directive 63 (PDD63)

37. PhD_TransLog_CI_Pro_Dis_020805 Transportation and Logistics Modals Airports/Aircraft Highways/Vehicles Pipelines Railroads/Trains Waterways/Vessels Airports/Aircraft Highways/Vehicles Pipelines Railroads/Trains Waterways/Vessels

38. PhD_TransLog_CI_Pro_Dis_020805 Number of CIs There are 13 general CIs defined by the Department of Homeland Security 1.Agriculture 2.Banking and Finance 3.Chem. Ind. & Haz Mat 4.Defense Indus. Base 5.Emergency Services 6.Energy 7.Food 7.Government 8.Info. and Telecom. 9.Postal and Shipping 10.Public Health 11.Transportation 12.Water Alphabet Order

39. PhD_TransLog_CI_Pro_Dis_020805 Other CIs Others include: SPAWAR – 10 with subsets InfraGard of North Texas – 9 CI could also be specific to area Port of Houston Others include: SPAWAR – 10 with subsets InfraGard of North Texas – 9 CI could also be specific to area Port of Houston

40. PhD_TransLog_CI_Pro_Dis_020805 Common Property of CI “… all complex collections of interacting components in which change often occurs as a result of learning processes; that is, they are complex adaptive systems (CASs).” 4

41. PhD_TransLog_CI_Pro_Dis_020805 Transportation and Logistics (Trans/Log) Overview

42. PhD_TransLog_CI_Pro_Dis_020805 Importance of Trans/Log “Transportation is one of the most important and increasingly complex infrastructure networks of our modern society” 5

43. PhD_TransLog_CI_Pro_Dis_020805 Transportation Definition “A facility consisting of the means and equipment necessary for the movement of passengers or goods” 6

44. PhD_TransLog_CI_Pro_Dis_020805 Logistics Definition “That part of the supply chain process that plans, implements, and controls the efficient, effective forward and reverse flow and storage of goods, services, and related information between the point of origin and the point of consumption in order to meet customers' requirements” 7

45. PhD_TransLog_CI_Pro_Dis_020805 Information is a Critical Component of Logistics Customer Financial Customs Air Freight Fwd Motor Rail Ocean Mfg Information Product/ Material Single Source Information Consolidator De-consolidator

46. PhD_TransLog_CI_Pro_Dis_020805 Trans/Log GDP Gross Domestic Product: 2003 8 8.5% 91.5% Trans/LogAll Other

47. PhD_TransLog_CI_Pro_Dis_020805 Formulating the Model

48. PhD_TransLog_CI_Pro_Dis_020805 Model

49. PhD_TransLog_CI_Pro_Dis_020805 Functional Analysis Perform Functional Analysis

50. PhD_TransLog_CI_Pro_Dis_020805 Model Parameters COST RISKTHROUGHPUT

51. PhD_TransLog_CI_Pro_Dis_020805 Identify Cost Parameters Accidents – There are cost estimates associated with each type of accident category that include: Non fatal and degree Fatal Delays – There are costs associated with delays of goods to market Accidents – There are cost estimates associated with each type of accident category that include: Non fatal and degree Fatal Delays – There are costs associated with delays of goods to market COST

52. PhD_TransLog_CI_Pro_Dis_020805 Identify Cost Parameters Highway Construction – There are cost estimates associated with all types of construction that include but are not limited to: Cost per feet of highway Rail damage per feet Bridge construction Routine maintenance Highway Construction – There are cost estimates associated with all types of construction that include but are not limited to: Cost per feet of highway Rail damage per feet Bridge construction Routine maintenance COST

53. PhD_TransLog_CI_Pro_Dis_020805 Identify Risks National Defense Industrial Association (NDIA) Information Briefing on the Department of Defense (DOD) CI Protection, July 3, 2002 Identifying, Understanding, and Analyzing Critical Infrastructure Interdependencies Hazard and Operations Analysis (HAZOP) Synthesis – Research, Investigate, and Interview National Defense Industrial Association (NDIA) Information Briefing on the Department of Defense (DOD) CI Protection, July 3, 2002 Identifying, Understanding, and Analyzing Critical Infrastructure Interdependencies Hazard and Operations Analysis (HAZOP) Synthesis – Research, Investigate, and Interview RISK

54. PhD_TransLog_CI_Pro_Dis_020805 Identify Risks Assess TLHV’s Risk 9 RISK

55. PhD_TransLog_CI_Pro_Dis_020805 Identify Stakeholders Fuse Trans/Log Highways and Vehicles (TLHV) with the CI Commuters Distribution Centers Utilities / Power Crews Emergency Responders Airports Water Ports Bus and Rail Stations DoD RISK

56. PhD_TransLog_CI_Pro_Dis_020805 Categorize Risks Theory of Scenario Structuring (TSS) Hierarchical Holographic Modeling (HHM) Anticipatory Failure Determination (AFD) Theory of Scenario Structuring (TSS) Hierarchical Holographic Modeling (HHM) Anticipatory Failure Determination (AFD) RISK

57. PhD_TransLog_CI_Pro_Dis_020805 THROUGH- PUT Identify Throughput Estimated traffic flow patterns are available from the respective Department of Transportation (DOT) cities

58. PhD_TransLog_CI_Pro_Dis_020805 Model Intricacies

59. PhD_TransLog_CI_Pro_Dis_020805 Assume Steady State Simulation Flow Diagram Input / Variables Likelihood

60. PhD_TransLog_CI_Pro_Dis_020805 Model Input Type of Disconnect (Continued) Terror Explosion Chemical Bio/Hazard Other Special Events Construction School Closings Time of Day Rush Hour AM PM Other Morning Lunch Afternoon Evening Late Night Early Morning Day of Wk Type of Disconnect Accident Chemical Multiple Fatality Single Fatality Multiple Injuries Severe Injury Minor Injury Fender Bender Natural Disaster Earthquake Flooding Hurricane Tornado Severe Weather Day of Wk Holliday New Years Easter Memorial Day 4th July Labor Day Thanks Giving Christmas

61. PhD_TransLog_CI_Pro_Dis_020805 Model Variables Geographical Interdependencies Power Lines Bridges Intersections Rail Lines DC Locations Water Ports Air Ports Coupling Relationship of Impact Power Lines Bridges Intersections Rail Lines DC Locations Water Ports Air Ports

62. PhD_TransLog_CI_Pro_Dis_020805 Transportation Network Nodes – Intersections Links – Arcs between nodes Geographical Interdependencies – Those CI’s in relation to the transportation network Nodes – Intersections Links – Arcs between nodes Geographical Interdependencies – Those CI’s in relation to the transportation network

63. PhD_TransLog_CI_Pro_Dis_020805 Graphical Representation TI RR DT TR i, j DFW TI – TX Instruments; CI 4 & 8 TR – Trinity River; CI 12 DT – Downtown; CI 2 & 5 RR – Railroad; 11 Nodes Links Geo. Inter. i, j

64. PhD_TransLog_CI_Pro_Dis_020805 Adaptive Model The likelihood of a disconnect changes with the state of the environment and time. Hence, the model requires minimal high-level inputs from the user in terms of the type and likelihood of disconnects that could occur. These inputs allow the model to become adaptive to the current environment and provide results that are more meaningful.

65. PhD_TransLog_CI_Pro_Dis_020805 Model Function

66. PhD_TransLog_CI_Pro_Dis_020805 Elements of the Model Geographical Interdependencies: Those CI that are within proximity of each other Temporal Range: The time of the incident State of Operation: Peak conditions, repair or restoration Coupling: The linearity and complexity of the interactions Geographical Interdependencies: Those CI that are within proximity of each other Temporal Range: The time of the incident State of Operation: Peak conditions, repair or restoration Coupling: The linearity and complexity of the interactions

67. PhD_TransLog_CI_Pro_Dis_020805 Estimate Cost Accidents Non fatal injuries Fatal Highway Construction Time Delays Goods to market Personal time Accidents Non fatal injuries Fatal Highway Construction Time Delays Goods to market Personal time Stochastic Monte Carlo Simulation

68. PhD_TransLog_CI_Pro_Dis_020805 Quantify and Rank Risks Bayesian Analysis Markov Chain Monte Carlo Simulation Failure Modes, Effects, and Criticality Analysis (FMECA) Risk Filtering, Ranking and Management (RFRM) Quantitative Risk Analysis (QRA) Fault Tree (FT) Event Tree (ET) Failure Modes, Effects, and Criticality Analysis (FMECA) Risk Filtering, Ranking and Management (RFRM) Quantitative Risk Analysis (QRA) Fault Tree (FT) Event Tree (ET)

69. PhD_TransLog_CI_Pro_Dis_020805 Estimate Throughput Throughput estimates for: Nodes Links Throughput estimates for: Nodes Links Stochastic Queuing Analysis Monte Carlo Simulation

70. PhD_TransLog_CI_Pro_Dis_020805 Model Output: Part I Economic Impact: The estimated Primary Metropolitan Statistical Area economic impact of a disconnect Risk Factors: The estimated amount of risk at each link and node of the transportation network Economic Impact: The estimated Primary Metropolitan Statistical Area economic impact of a disconnect Risk Factors: The estimated amount of risk at each link and node of the transportation network

71. PhD_TransLog_CI_Pro_Dis_020805 Model Output: Part I Throughput: The amount of vehicles per unit of time passing a defined link or node of the transportation network

72. PhD_TransLog_CI_Pro_Dis_020805 Weighted Analysis Use Weighted Analysis to arrive at a single output metric Value and Weight for: 1. Cost 2. Risk 3. Throughput Use Weighted Analysis to arrive at a single output metric Value and Weight for: 1. Cost 2. Risk 3. Throughput

73. PhD_TransLog_CI_Pro_Dis_020805 Model Output: Part II Network Node Performance: Overall single output metric for each node and link

74. PhD_TransLog_CI_Pro_Dis_020805 Metrics and Validation

75. PhD_TransLog_CI_Pro_Dis_020805 Metrics Risk mitigation Diverting traffic before disconnect Strategically locating emergency responders for obviating potential disconnects Risk mitigation Diverting traffic before disconnect Strategically locating emergency responders for obviating potential disconnects

76. PhD_TransLog_CI_Pro_Dis_020805 Metrics Descriptive of what occurs: Before disconnect After disconnect Quantify critical nodes for resource deployment before disconnect occurs Quantify affects after disconnect occurs Descriptive of what occurs: Before disconnect After disconnect Quantify critical nodes for resource deployment before disconnect occurs Quantify affects after disconnect occurs

77. PhD_TransLog_CI_Pro_Dis_020805 Validate Model Test model – threshold Replicate model in Houston Test model – threshold Replicate model in Houston

78. PhD_TransLog_CI_Pro_Dis_020805 Benefits

79. PhD_TransLog_CI_Pro_Dis_020805 Benefits Model for municipalities to use for resource allocation based on terrorist attacks on the Trans/Log CI Reduce resource waste Increase efficiencies Align emergency plan based on severity Model for municipalities to use for resource allocation based on terrorist attacks on the Trans/Log CI Reduce resource waste Increase efficiencies Align emergency plan based on severity

80. PhD_TransLog_CI_Pro_Dis_020805 Benefits Homeland Security Funding: Earmark funding to areas that pose greatest risk of a terrorist attack Future Highway Designs: Compare new proposed highway design against model for minimizing risk and cost due to disconnects in system Homeland Security Funding: Earmark funding to areas that pose greatest risk of a terrorist attack Future Highway Designs: Compare new proposed highway design against model for minimizing risk and cost due to disconnects in system

81. PhD_TransLog_CI_Pro_Dis_020805 Conclusion

82. PhD_TransLog_CI_Pro_Dis_020805 Conclusion Systems Engineering approach elevates the decision making process by considering the system versus an entity CI is dynamic and intertwined with the system’s interdependencies Affects citizens’ way of life Impacts companies way of doing business Exponentially growing in complexity 10 Systems Engineering approach elevates the decision making process by considering the system versus an entity CI is dynamic and intertwined with the system’s interdependencies Affects citizens’ way of life Impacts companies way of doing business Exponentially growing in complexity 10

83. PhD_TransLog_CI_Pro_Dis_020805 Conclusion Trans/Log accounts for almost 9% of the US GDP Pivotal for US and world economy Fosters commerce Trans/Log accounts for almost 9% of the US GDP Pivotal for US and world economy Fosters commerce

84. PhD_TransLog_CI_Pro_Dis_020805 Conclusion SE Critical Infrastructures Transportation/ Logistics

85. PhD_TransLog_CI_Pro_Dis_020805 Conclusion Provide a systematic approach for understanding and quantifying the Trans/Log CI and its Interdependencies Develop Trans/Log CI framework to model resource allocation in an event of a disconnect Provide a systematic approach for understanding and quantifying the Trans/Log CI and its Interdependencies Develop Trans/Log CI framework to model resource allocation in an event of a disconnect

86. PhD_TransLog_CI_Pro_Dis_020805 Footnotes 1.International Council on Systems Engineering, (Seattle, WA, accessed 7 February 2005); available from http://www.incose.org/practice/whatissystemseng.aspx; Internet. 2.Benjamin S. Blanchard, Logistics Engineering and Management, (Upper Saddle River, New Jersey: Pearson/Prentice Hall, 2004), p. 28. 3.The Whit House: Office of the Press Secretary, Fact Sheet, May 22, 1998. [Online]. Available at http://www.fas.org/irp/offdocs/pdd-63.htm. 4.Steven M. Rinaldi, James P. Peerenboom, and Terrence K. Kelly, Identifying, Understanding, and Analyzing Critical Infrastructure Interdependencies, (IEEE Control System Magazine, December 2001), p.13. 5.George Mason University, Systems Engineering Research and Operations. 1.International Council on Systems Engineering, (Seattle, WA, accessed 7 February 2005); available from http://www.incose.org/practice/whatissystemseng.aspx; Internet. 2.Benjamin S. Blanchard, Logistics Engineering and Management, (Upper Saddle River, New Jersey: Pearson/Prentice Hall, 2004), p. 28. 3.The Whit House: Office of the Press Secretary, Fact Sheet, May 22, 1998. [Online]. Available at http://www.fas.org/irp/offdocs/pdd-63.htm. 4.Steven M. Rinaldi, James P. Peerenboom, and Terrence K. Kelly, Identifying, Understanding, and Analyzing Critical Infrastructure Interdependencies, (IEEE Control System Magazine, December 2001), p.13. 5.George Mason University, Systems Engineering Research and Operations.

87. PhD_TransLog_CI_Pro_Dis_020805 Footnotes 6.WordNet ® 2.0, © 2003 Princeton University 7.The Michigan Roundtables (Council of Logistics Management) 8.Perry A. Trunick, How to Beat the High Cost of Shipping, Logistics Today, July, 2004. 9.NDIA Information Briefing. DoD Critical Infrastructure Protection, July 3, 2002. 10.Steven M. Rinaldi, James P. Peerenboom, and Terrence K. Kelly, Identifying, Understanding, and Analyzing Critical Infrastructure Interdependencies, (IEEE Control System Magazine, December 2001), p.24. 6.WordNet ® 2.0, © 2003 Princeton University 7.The Michigan Roundtables (Council of Logistics Management) 8.Perry A. Trunick, How to Beat the High Cost of Shipping, Logistics Today, July, 2004. 9.NDIA Information Briefing. DoD Critical Infrastructure Protection, July 3, 2002. 10.Steven M. Rinaldi, James P. Peerenboom, and Terrence K. Kelly, Identifying, Understanding, and Analyzing Critical Infrastructure Interdependencies, (IEEE Control System Magazine, December 2001), p.24.

88. PhD_TransLog_CI_Pro_Dis_020805 notes 1. Here is what I want to model 2. Here is my output 3. Use SE to develop model 1. Need requirements 2. Need resources 3. Need constraints 1. Here is what I want to model 2. Here is my output 3. Use SE to develop model 1. Need requirements 2. Need resources 3. Need constraints

89. PhD_TransLog_CI_Pro_Dis_020805 State the Problem Develop case for problem – research articles from Newspapers Magazines Journals Other articles not elsewhere classified (n.e.c.) Develop case for problem – research articles from Newspapers Magazines Journals Other articles not elsewhere classified (n.e.c.)