IT Operations Manager The Midtown GroupIT Operations ManagerWashington, DC$90,000–$115,000 / yearFull timeYou'll partner closely with leadership, vendors, and internal stakeholders to deliver exceptional user experiences, modernize processes, and ensure operational excellence across a hybrid workforce. Lead large-scale device deployment initiatives and workforce onboarding efforts in partnership with managed service providers and internal teams.
Automotive Parts Manager Highline Passport AutoAutomotive Parts Manager HighlineCamp Springs, MDFull timeWe are seeking an experienced Highline/Luxury Automotive Parts Manager to lead our parts department and support our service, sales, and wholesale operations in Suitland Md. We will soon have a new HIGHLINE automotive brand to add to our established automotive group of more than 30 years!
NewProject Manager JobotProject ManagerColumbia, MD$90,000–$125,000 / yearInformation collected and processed as part of your Jobot candidate profile, and any job applications, resumes, or other information you choose to submit is subject to Jobot's Privacy Policy, as well as the Jobot California Worker Privacy Notice and Jobot Notice Regarding Automated Employment Decision Tools which are available at jobot.com/legal. Manage project setup logistics—submittals, RFIs, change orders, materials, labor, budgets, punch lists.
NewData Center Category Manager, AWS Data Center Sourcing & Procurement Amazon Data Services, Inc.Data Center Category Manager, AWS Data Center Sourcing & ProcurementArlington, VATo be successful in this role you will be highly analytical; think strategically and globally; exhibit curiosity and learning drive; have a sense of urgency to meet customer timelines, succeed in a fast-paced environment; and have a high level of customer focus and business judgement. As a Procurement Category Manager, you will create and implement sourcing strategies within construction services space and collaborate with internal business partners and suppliers to drive efficiencies, reduce risks, and costs for Amazon.
GeoStructural Division Manager Hillis-CarnesGeoStructural Division ManagerAnnapolis Junction, MDFull timeHillis-Carnes Engineering Associates (HCEA) is a top tier, multi-disciplined engineering firm with advanced capabilities in geotechnical and geostructural engineering, environmental consulting, specialty construction, construction materials engineering and testing, and third-party inspections. This exciting and dynamic position requires excellence in the following competencies: · Division Management: Provide oversight of engineering and support staff, senior review of technical products, good loss prevention practices, and lead the growth of the division.
Financial Manager Savantage SolutionsFinancial ManagerRockville, MD$110,000–$132,000 / yearSavantage Solutions is seeking a Financial Manager to join our professional services team supporting the mission of a federal government agency dedicated to enabling the Department of Defense, the U.S. Government, and international partners to counter and deter weapons of mass destruction and improvised threat networks. Document development efforts and produce guides, job aids and other information to support the Agency’s automated spend plan management system and other financial tools (to include but not limited to DAI, Joint Integrated CBRN Analytic Platform (JICAP), and Dormant Account Review Quarterly (DAR-Q).
Sr. Manager, HRIS - $140K-$155K - DC Beacon Hill Staffing Group, LLCSr. Manager, HRIS - $140K-$155K - DCWashington, DC, District of Columbia$140,000–$155,000 / yearFull timeLearn more about Beacon Hill and our specialty divisions, Beacon Hill Associates, Beacon Hill Financial, Beacon Hill HR, Beacon Hill Legal, Beacon Hill Life Sciences and Beacon Hill Technologies by visiting www.bhsg.com. Our niche brands offer a complete suite of staffing services to emerging growth companies and the Fortune 500 across market sectors, career specialties/disciplines and industries.
NewCommercial Construction Assistant Project Manager – Mission Critical JobotCommercial Construction Assistant Project Manager – Mission CriticalFalls Church, VA$90,000–$110,000 / yearOur client is a well-established commercial general contractor delivering high-quality construction services across a diverse portfolio of projects, including mission critical, multifamily, institutional, and large-scale commercial developments. Information collected and processed as part of your Jobot candidate profile, and any job applications, resumes, or other information you choose to submit is subject to Jobot's Privacy Policy, as well as the Jobot California Worker Privacy Notice and Jobot Notice Regarding Automated Employment Decision Tools which are available at jobot.com/legal.
NewManager of Client Relations (Nuclear Industry) JobotManager of Client Relations (Nuclear Industry)Parkville, MD$170,000–$230,000 / yearInformation collected and processed as part of your Jobot candidate profile, and any job applications, resumes, or other information you choose to submit is subject to Jobot's Privacy Policy, as well as the Jobot California Worker Privacy Notice and Jobot Notice Regarding Automated Employment Decision Tools which are available at jobot.com/legal. You will represent a full portfolio of engineered products and services, working closely with engineering, manufacturing, and project teams to deliver high impact solutions to clients.
NewSr. Energy Strategy Manager - AWS Energy Team, AWS Infra Energy Team Amazon Data Services, Inc.Sr. Energy Strategy Manager - AWS Energy Team, AWS Infra Energy TeamArlington, VAAmazon is seeking a self-starter to join the AWS Energy team that sits within the AWS Infrastructure Services org in pioneering the future for data center utility power by developing and executing the strategy by which AWS delivers energy projects and partners with electric utilities and energy companies across the Americas. Within the overarching strategy, this individual must be resilient in exploring and discovering new supply opportunities (that delivery both near term capacity with an accelerated path to net-zero carbon supply), ultimately converting them into tactically sound and executable energy projects while working to reduce energy capital and operating expenses.
Territory Manager II Swisher International, Inc.Territory Manager IIArlington, VAWith a rich history, Swisher serves adult consumers through a diverse range of businesses, including Swisher Sweets Cigar Company, Helme Tobacco Co., Hempire, Rogue Holdings, and Drew Estate: The Rebirth of Cigars. This role uses facts, analytics, and market intelligence to influence customer decisions, drive distribution, and deliver measurable top and bottom-line growth and grow market share.
NewSenior Public Relations Manager (Law Firm) JobotSenior Public Relations Manager (Law Firm)Washington, DC$175,000–$200,000 / yearInformation collected and processed as part of your Jobot candidate profile, and any job applications, resumes, or other information you choose to submit is subject to Jobot's Privacy Policy, as well as the Jobot California Worker Privacy Notice and Jobot Notice Regarding Automated Employment Decision Tools which are available at jobot.com/legal. By applying for this job, you agree to receive calls, AI-generated calls, text messages, or emails from Jobot, and/or its agents and contracted partners.
NewSenior Finance Manager Vaco LLCSenior Finance ManagerBethesda, MD$125–$150Determining compensation for this role (and others) at Vaco by Highspring depends upon a wide array of factors including but not limited to: the individual’s skill sets, experience and training; licensure and certification requirements; office location and other geographic considerations; other business and organizational needs. Determining compensation for this role (and others) at Vaco/Highspring depends upon a wide array of factors including but not limited to the individual’s skill sets, experience and training, licensure and certifications, office location and other geographic considerations, as well as other business and organizational needs.
NewSenior Real Estate Development Manager, AWS Infrastructure Services Amazon Data Services, Inc.Senior Real Estate Development Manager, AWS Infrastructure ServicesArlington, VAWe are looking for a talented professional to join the AWS Real Estate Team who will operate on both strategic and tactical levels to support the expansion of AWS’s Data Center Network in the U.S. In this role, you will work directly with land owners, data center developers, PE firms, local jurisdictions, land use attorneys and consultants to identify and secure agreements to facilitate AWS’s expansion. - Work cross-functionally with other internal and external teams, including Design Engineering, Legal, Economic Development, Public Policy, Construction and Capacity Planning, to inform a regional real estate strategy.
NewManager - Platform Engineering (ServiceNow) OneMain FinancialManager - Platform Engineering (ServiceNow)Baltimore, MD$105,000–$126,000 / yearAs an ideal candidate, you will be responsible for managing and scaling a talented team of ServiceNow analysts, engineers and specialists while positioning the platform as a strategic enabler for partner teams across the enterprise such as Prod Ops, App Dev, EA, IAM, HR, Legal, Compliance, Facilities, Procurement, Finance, Cyber. Rather than owning functional delivery in those domains, your responsibility will be to ensure the ServiceNow platform, and the team deliver the workflows, automations, integrations, insights, and AI-driven enhancements these teams need to operate effectively, securely, and at scale.
NewBRAC Property Conveyance Program Manager Calibre SystemsBRAC Property Conveyance Program ManagerArlington, VAFive to ten years recent conveyance experience working directly with DoD in coordinationwith Federal, State and community stakeholders (with USACE, GSA, OEA, Army or otherService Staffs, Army Secretariat (Deputy Assistant Secretary of the Army (DASA) -Installations, Housing and Partnerships (IH&P)or Environment, Safety and Occupational Health(ESOH),ASAIE&E),OGC, ELD,andOSD). Experience with writing in the Army style is highly desirable (e.g., DA Pam 600-67, Effective Writing for Army Leaders; Army Regulation 25-50, Preparing and Managing Correspondence; the Associated Press Style Book); Ability to communicate effectively, both verbally and in writing, in the Headquarters Department of the Army environment.
NewLicensed Salon Manager Sport ClipsLicensed Salon ManagerGlen Burnie, MD$30–$50 / hourLicensed stylists who are not yet ready for a Salon Manager role can apply to our Manager-in-Training program, which provides hands-on leadership development in scheduling, inventory, customer service, and salon operations. This role is ideal for a licensed cosmetologist or barber who enjoys coaching teams, managing salon operations, and delivering consistent, high-quality customer experience.
NewDialysis Clinical Manager Registered Nurse - RN Fresenius Medical CareDialysis Clinical Manager Registered Nurse - RNBaltimore, MDOther: • Collaborates closely with, providing oversight as needed to, the Clinical Manager/Charge RN acting as nurse manager, the Medical Director, and the physicians regarding the direct patient care responsibilities within the facility to ensure the provision of outstanding quality of patient care, as defined by the FMS quality goals, and compliance with the pertinent company policies and procedures. • Demonstrated leadership competencies and management skills for the position, including excellent communication, customer service, continuous quality improvement, relationship development, results orientation, team building, motivating employees, performance management and decision making.
NewSoftware Engineering Manager - (Rails, Node, Angular, JavaScript) OneMain FinancialSoftware Engineering Manager - (Rails, Node, Angular, JavaScript)Baltimore, MD$110,000–$132,000 / yearIn this role, you will lead the team responsible for our shared application platform and its operational excellence—ensuring deployments run smoothly, environments remain stable, and cross-functional engineering teams are empowered to deliver with consistency and confidence. 8–10+ years of experience in software engineering, 3 or more years of progressive responsibility as an engineer on development teams directly responsible for building and delivering software-intensive systems.
NewSenior Capture Manager CredenceSenior Capture ManagerMcLean, VAWe are looking for self-motivating employees who are proficient in and can lead all aspects of the pre-award capture lifecycle in areas of Defense and Military, to include opportunity identification, research, teaming conversations, negotiations, and proposal leadership (working closely with a proposal team). Must be experienced with leading task order capture efforts for one or more large-scale Defense and Military IDIQ contracts, to include developing overall IDIQ capture strategies, creatively and dynamically organizing efforts for maximum efficiency, and driving actions and priorities.
NewDialysis Clinical manager Registered Nurse - RN Fresenius Medical CareDialysis Clinical manager Registered Nurse - RNBaltimore, MDOther: • Collaborates closely with, providing oversight as needed to, the Clinical Manager/Charge RN acting as nurse manager, the Medical Director, and the physicians regarding the direct patient care responsibilities within the facility to ensure the provision of outstanding quality of patient care, as defined by the FMS quality goals, and compliance with the pertinent company policies and procedures. • Demonstrated leadership competencies and management skills for the position, including excellent communication, customer service, continuous quality improvement, relationship development, results orientation, team building, motivating employees, performance management and decision making.
NewLicensed Assistant Salon Manager Sport ClipsLicensed Assistant Salon ManagerBel Air, MD$26–$44 / hourSport Clips Haircuts in Bel Air is now hiring an Assistant Salon Manager to support daily salon operations, lead a high-performing team, and deliver an exceptional client experience. This role is perfect for an experienced licensed hair stylist, barber, or cosmetologist ready to grow their leadership career while still doing what they love, cutting hair.
NewMarketing Project Manager System OneMarketing Project ManagerVienna, VAIn addition, the Project Manager works closely with the product owner(s), strategy teams and scrum masters within our Agile Release Train to coordinate and traffic work to external vendors, agency partners, and internal business partners. • Lead efforts and collaborate with the cross-functional business unit teams to identify all tasks needed to complete a marketing campaign and strategically perform or delegate those tasks to appropriate team members.
NewAssistant General Manager Fresh BaguetteAssistant General ManagerBethesda, MD$23–$24 / hourThis value is evident in everything we do, from the smell of scratch-made artisanal croissants and organic bread baking fresh throughout the day to the beauty of hand-crafted pastries, delicious coffee, and savory creations delivered in a warm and inviting atmosphere. The company was founded in Bethesda, MD in 2013, to bring fresh, made-from-scratch organic breads, pastries, sweets, and croissant items inspired by bakeries in France to the DMV area.
NewGeneral Manager Fresh BaguetteGeneral ManagerWashington, DCThis value is evident in everything we do, from the smell of scratch-made artisanal croissants and organic bread baking fresh throughout the day to the beauty of hand-crafted pastries, delicious coffee, and savory creations delivered in a warm and inviting atmosphere. This full-time, salaried role is hands-on and people-focused, requiring a strong leader who can inspire teams, deliver outstanding customer experiences, and drive operational and financial success.
Preconstruction Project Executive - Design Manager HITT ContractingPreconstruction Project Executive - Design ManagerFalls Church, VA$130,000–$185,000 / yearIn addition, this role provides design-build leadership and design management during pursuits and preconstruction by analyzing RFP/RFQ requirements, coordinating the preconstruction team leads, guiding design team selection, and managing the design phase to maintain alignment to cost, schedule, constructability, procurement, and client performance requirements. The Preconstruction Executive – Design Manager reports directly to the Senior Vice President of Strategic Services and supports the Vice President of Preconstruction while leading the development and execution of the company’s design build strategy.
NewManager of Market Analysis Erickson Senior LivingManager of Market AnalysisCatonsville, MD$85,000–$100,000 / yearIdentify consumer market characteristics and key target market/primary market factors, including geographic barriers, psychological barriers (price, geographic), product preferences and concerns, reputation issues, etc. This position is responsible for delivering data-driven insights and analysis to support ground‑up developments, acquisitions, expansions at existing campuses, and new product or service offerings.
Assistant Preconstruction Manager HITT ContractingAssistant Preconstruction ManagerFalls Church, VA$82,000–$117,000 / yearThe Assistant Preconstruction Manager reports to the Preconstruction Manager and the Senior Preconstruction Manager and is responsible in assisting with Preconstruction services from initial intent through construction documents for assigned projects. The Assistant Preconstruction Manager must have proficient knowledge of the construction divisions and be able to quantify and manage specific trades to provide accurate pricing proposals.
Preconstruction Manager HITT ContractingPreconstruction ManagerFalls Church, VA$100,000–$145,000 / yearEstimating services include feasibility studies, budgets from conceptual design to bidding, comparative studies, value engineering and presentation of the same to both internal and external clients. The Preconstruction Manager is responsible for all Preconstruction phase estimating services from initial programmatic intent through construction documents pricing for assigned projects.
NewDeputy Embedded Software Engineering Manager Johns Hopkins Applied Physics Laboratory (APL)Deputy Embedded Software Engineering ManagerLaurel, MD$105,000–$290,000We are seeking an Assistant Group Supervisor of the Embedded Applications Group to help shape the direction and work for a multifaceted and passionate organization of 50+ engineers that crafts and delivers world class embedded software that enables our nation’s space exploration and national security. Develop strategic plans and the technical roadmap for the continuous advancement of the group’s technology, products, staff, and services such as spacecraft flight software engineering, high-fidelity real-time test environments, and autonomy systems.
Resident Construction Manager - Sewer Pumping Station Facilities Whitman, Requardt & Associates, LLPResident Construction Manager - Sewer Pumping Station FacilitiesBaltimore, MDFull timeThe RCM is responsible for providing daily construction management and inspection services for pumping station facilities including new construction and rehabilitation or upgrades including mechanical, electrical and pump control systems and related yard piping and civil site improvements. Whitman, Requardt & Associates, LLP (WRA) is seeking a qualified Resident Construction Manager for sanitary sewer pumping station facility construction projects in the Baltimore Metropolitan Area.
NewProcurement Regulatory Compliance Manager Johns Hopkins Applied Physics Laboratory (APL)Procurement Regulatory Compliance ManagerLaurel, MD$58,700–$146,300As part of the Procurement Compliance Section support both internally and externally conducted audits including reviewing procurement purchase order and subcontract documentation, responding to auditor questions, and addressing any post-audit actions. As a Procurement Compliance Manager your primary responsibility will be to proactively assess the impact of changing regulations in the Federal Acquisition Regulation and Defense Federal Acquisition Regulation relating to Procurement, new Executive Orders, and other related government audit trends.
MEP Manager HITT ContractingMEP ManagerFalls Church, VA$95,000–$135,000 / yearThe MEP Manager oversees multiple projects; responsible for providing support to the MEP Site Operations teams at the project level in the delivery of a consistent MEP product and brand. Every day, our team members do amazing things in pursuit of our shared purpose to build trust with our clients, partners, subcontractors, and teammates.
NewVendor Relationship Manager - Security System OneVendor Relationship Manager - SecurityVienna, VA$65–$65 / hourThe Security Vendor Management (SVM) team provides support to business units within the Security organization by managing, negotiating, and overseeing the purchase of contracted products and/or services. The team conducts general relationship management for Security business unit contract owners with contract needs, vendor selections, vendor performance and escalations, requisitions, purchase orders, and invoice review.
Safety Manager HITT ContractingSafety ManagerFalls Church, VA$95,000–$140,000 / yearEvery day, our team members do amazing things in pursuit of our shared purpose to build trust with our clients, partners, subcontractors, and teammates. This individual regularly assesses the safety needs of their assigned business units or projects and utilizes their assigned resources to meet those needs.
Commercial Construction Project Manager - Multifamily HITT ContractingCommercial Construction Project Manager - MultifamilyFalls Church, VA$96,800–$132,000 / yearThe PM provides leadership and serves as the liaison between project team members to promote the interest of both the business and clients in all matters, as well as demonstrate the characteristics of a mid-level leader. Every day, our team members do amazing things in pursuit of our shared purpose to build trust with our clients, partners, subcontractors, and teammates.
Commercial Construction Senior Project Manager - GovDirect HITT ContractingCommercial Construction Senior Project Manager - GovDirectFalls Church, VA$121,000–$165,000 / yearEvery day, our team members do amazing things in pursuit of our shared purpose to build trust with our clients, partners, subcontractors, and teammates. In accordance with Virginia Senate Bill 215 (SB 215), the base salary range for this position is: $121,000.00 - $165,000.00Compensation in other cities and states may vary.
Commercial Construction Project Manager - Healthcare HITT ContractingCommercial Construction Project Manager - HealthcareFalls Church, VA$96,800–$132,000 / yearThe PM provides leadership and serves as the liaison between project team members to promote the interest of both the business and clients in all matters, as well as demonstrate the characteristics of a mid-level leader. Every day, our team members do amazing things in pursuit of our shared purpose to build trust with our clients, partners, subcontractors, and teammates.
NewCommercial Construction Senior Project Manager - Advanced Manufacturing HITT ContractingCommercial Construction Senior Project Manager - Advanced ManufacturingFalls Church, VA$121,000–$165,000 / yearEvery day, our team members do amazing things in pursuit of our shared purpose to build trust with our clients, partners, subcontractors, and teammates. In accordance with Virginia Senate Bill 215 (SB 215), the base salary range for this position is: $121,000.00 - $165,000.00Compensation in other cities and states may vary.
Commercial Construction Senior Project Manager - Mission Critical HITT ContractingCommercial Construction Senior Project Manager - Mission CriticalFalls Church, VA$121,000–$165,000 / yearEvery day, our team members do amazing things in pursuit of our shared purpose to build trust with our clients, partners, subcontractors, and teammates. In accordance with Virginia Senate Bill 215 (SB 215), the base salary range for this position is: $121,000.00 - $165,000.00Compensation in other cities and states may vary.
Commercial Construction Senior Project Manager - Healthcare HITT ContractingCommercial Construction Senior Project Manager - HealthcareFalls Church, VA$121,000–$165,000 / yearEvery day, our team members do amazing things in pursuit of our shared purpose to build trust with our clients, partners, subcontractors, and teammates. In accordance with Virginia Senate Bill 215 (SB 215), the base salary range for this position is: $121,000.00 - $165,000.00Compensation in other cities and states may vary.
Commercial Construction Senior Project Manager - GovCloud HITT ContractingCommercial Construction Senior Project Manager - GovCloudFalls Church, VA$121,000–$165,000 / yearEvery day, our team members do amazing things in pursuit of our shared purpose to build trust with our clients, partners, subcontractors, and teammates. In accordance with Virginia Senate Bill 215 (SB 215), the base salary range for this position is: $121,000.00 - $165,000.00Compensation in other cities and states may vary.
Commercial Construction Senior Project Manager - Multifamily HITT ContractingCommercial Construction Senior Project Manager - MultifamilyFalls Church, VA$121,000–$165,000 / yearEvery day, our team members do amazing things in pursuit of our shared purpose to build trust with our clients, partners, subcontractors, and teammates. In accordance with Virginia Senate Bill 215 (SB 215), the base salary range for this position is: $121,000.00 - $165,000.00Compensation in other cities and states may vary.
Commercial Construction Assistant Project Manager - GovCloud HITT ContractingCommercial Construction Assistant Project Manager - GovCloudFalls Church, VA$77,000–$110,000 / yearGather data, interpret it into meaningful information, and relay that information through clear, concise communication strategies; ability to see how pieces and processes fit into and affect the bigger picture/business model. An Assistant Project Manager (APM) obtains, evaluates, coordinates and distributes the information and authorizations necessary to construct projects on time, within budget and to the quality specified.
NewCommercial Construction Assistant Project Manager - Advanced Manufacturing HITT ContractingCommercial Construction Assistant Project Manager - Advanced ManufacturingFalls Church, VA$77,000–$110,000 / yearGather data, interpret it into meaningful information, and relay that information through clear, concise communication strategies; ability to see how pieces and processes fit into and affect the bigger picture/business model. An Assistant Project Manager (APM) obtains, evaluates, coordinates and distributes the information and authorizations necessary to construct projects on time, within budget and to the quality specified.
Commercial Construction Assistant Project Manager - GovDirect HITT ContractingCommercial Construction Assistant Project Manager - GovDirectFalls Church, VA$77,000–$110,000 / yearGather data, interpret it into meaningful information, and relay that information through clear, concise communication strategies; ability to see how pieces and processes fit into and affect the bigger picture/business model. An Assistant Project Manager (APM) obtains, evaluates, coordinates and distributes the information and authorizations necessary to construct projects on time, within budget and to the quality specified.
Commercial Construction Assistant Project Manager - Mission Critical HITT ContractingCommercial Construction Assistant Project Manager - Mission CriticalFalls Church, VA$77,000–$110,000 / yearGather data, interpret it into meaningful information, and relay that information through clear, concise communication strategies; ability to see how pieces and processes fit into and affect the bigger picture/business model. An Assistant Project Manager (APM) obtains, evaluates, coordinates and distributes the information and authorizations necessary to construct projects on time, within budget and to the quality specified.
General Manager (Scaffolding Projects) System OneGeneral Manager (Scaffolding Projects)20724, MDThe Operations Manager and field leadership team will report directly to this role, with responsibility for executing daily operations, workforce planning, scheduling, and project coordination to meet the demands of complex scaffolding installations. The General Manager will oversee a growing regional team supporting scaffolding construction projects, delivering safe, efficient, and compliant access solutions across a range of job sites.
NewConstruction Project Manager, CES Constellation EnergyConstruction Project Manager, CESWashington, DC$90,000–$100,000Bachelor's degree in engineering, construction project management, or architecture in lieu of degree, an associate's degree or 2-years of construction trade school plus at least 1-year of relevant construction field experience, or a high school diploma/GED plus 3-years of relevant construction field experience. Assists in providing oversight of subcontractors, monitors work for compliance with contract documents, coordinates work with building management, supports project team in the implementation of all scopes of work, helps to ensure site quality and safety, and submits detailed daily progress reports.
NewRevenue Manager Town of ViennaRevenue ManagerVienna, VA$96,511–$155,383 / yearReads journals, manuals and professional publications; speaks informally to groups of co-workers, staff in other organizational agencies, general public, people in other organizations and presents training; composes original reports, training and other written materials, using proper language, punctuation, grammar and style. Uses mathematics involving the practical application of fractions, percentages, ratios and proportions; or measurements, logarithmic, or geometric construction; may use algebraic solutions of equations and inequalities; descriptive statistics; deductive geometry, plane and solid, and rectangular coordinates; mathematical and classifications or schemes.