• Genesis of the Indian MBT
• Feasibility Study
• Subsystems Development by DRDO Laboratories
• Testing and Evaluation
• User Acceptance Contributions by Industries, Quality Assurance Agencies and Users
• Monitoring and Reviews
• Development to Production
• The Spin-offs
• Criticism and Response
• Milestones
• Personalities
• Abbreviations
• Committee for the Book on Arjun MBT
• Comparison with World-class Tanks References

The evaluation of the UNDP contribution to mine action is an independent thematic evaluation that emphasizes an impact approach conducted by the Independent Evaluation Office (IEO) of the United Nations Development Programme (UNDP) in 2014. The evaluation, focuses on the social and economic impacts of UNDP support to efforts to reduce the threat and impact of mines and explosive remnants of war.
(source: Nielsen Book Data)

• The origins of the US fixed-wing gunships in Vietnam
• The AC-119G/K gunship program: an overview
• A wondrous variety: moving towards the Spectre
• Final production and development and operations in Vietnam
• Expansion of the AC-130 fleet: it really was a surprise package
• Development and deployment of the new AC-130s
• The war grinds on
• Linebacker I and II: America's involvement winds down
• "Goodbye Vietnam!": the AC-130s transition
• AC-130s and the birth of US Special Operations Command
• The early 1990s: the Persian Gulf to Somalia
• The late 1990s: repair, upgrade, and a new model
• AC-130s on the fringes: Kosovo and Operation Allied Force
• Operation Enduring Freedom
• Operation Iraqi Freedom
• Recent events, modifications, and policy decisions
• Conclusion: some final thoughts about the night hunters
• Notes
• Glossary of acronyms.

In Night Hunters , air power historian William P. Head provides the first detailed study of the development and deployment of the AC-130 gunship. While other airframes and other types of close air support (CAS) and interdiction weapon systems preceded or flew with the AC-130s, this four-engine cargo airframe proved to be not only the longest serving fixed-wing gunship but also the most effective by far. During the Vietnam War, the US military developed new tactics and weapons systems to counter a diversity of enemy tactics and geographic features, the difficult climate, and the shifting diplomatic context. One of the most important was the development of the AC-130. Its ability to transport heavier payloads at higher altitudes across longer distances made it the logical choice to be the final Vietnam-era fixed-wing gunship and the only one that continues to fly missions in the twenty-first century. In addition, it employed many of the most advanced weapons, sensors, targeting devices, and fire control systems of the 1970s or of any era. By recounting both the technical development and the combat operations of the plane, and by looking at the proposed alternatives for its use in the War on Terror, Night Hunters offers a clear view of the role of gunships and of close air support in US wars. In today's never-ending brushfire wars, the AC-130s continue to uphold their reputation for excellence.
(source: Nielsen Book Data)

• The gift of adventure
• Ace of spades
• Come up and get me
• Escape from near space
• Combat
• Hanoi
• Home skies
• Destination : unknown; fuel on board: zero
• Ballooning and salooning.

A few years after his release from a North Vietnamese prisoner-of-war camp in 1973, Colonel Joseph Kittinger retired from the Air Force. Restless and unchallenged, he turned to ballooning, a lifelong passion as well as a constant diversion for his imagination during his imprisonment. His primary goal was a solitary circumnavigation of the globe, and in its pursuit he set several ballooning distance records, including the first solo crossing of the Atlantic in 1984. But the aeronautical feats that first made him an American hero had occurred a quarter of a century earlier. By the time Kittinger was shot down in Vietnam in 1972, his Air Force career was already legendary. He had made a name for himself at Holloman Air Force Base near Alamogordo, New Mexico, as a test pilot who helped demonstrate that egress survival for pilots at high altitudes was possible in emergency situations. Ironically, Kittinger and his pre-astronaut colleagues would help propel Americans into space using the world's oldest flying machine--the balloon. Kittinger's work on Project Excelsior--which involved daring high-altitude bailout tests--earned him the Distinguished Flying Cross long before he earned a collection of medals in Vietnam. Despite the many accolades, Kittinger's proudest moment remains his free fall from 102,800 feet during which he achieved a speed of 614 miles per hour. In this long-awaited autobiography, Kittinger joins author Craig Ryan to document an astonishing career. Selected by "Popular Mechanics" as a Top Book of 2010.
(source: Nielsen Book Data)

The system of coastal defenses built by the federal government after the War of 1812 was more than a series of forts standing guard over a watery frontier. It was an integrated and comprehensive plan of national defense developed by the U.S. Army Corps of Engineers, and it represented the nation's first peacetime defense policy. Known as the 'Third System' since it replaced two earlier attempts, it included coastal fortifications, but also denoted the values of the society that created it. The governing defense policy was one that combined permanent fortifications to defend seaports, a national militia system, and a small regular army. The Third System remained the defense paradigm in the United States from 1816 to 1861, when the onset of the Civil War changed that paradigm. In addition to providing the country with military security, the system also provided the context for the ongoing debates in Congress over national defense through the annual congressional debates on military funding. In charting the philosophy, construction, and maintenance of the forts of the Third System, a history of antebellum American national defense policy emerges, and permits an investigation of the political, economic, social, and military development of the U.S. between the War of 1812 and the Civil War.
(source: Nielsen Book Data)

• v.1 (1910-1914).-- v.2 (1914-1916).-- v .3 (1917 yılı).-- v.4 (1918 yılı).-- v.5 (Tablolar-haritalar-çizimler ve fotoğraflar)

• Introduction
• The humanitarian impact of cluster munitions
• Cluster munition contamination in southern Lebanon
• Cluster munition contamination in Cambodia
• Conclusion.

"The humanitarian impact of cluster munitions is dependent on the degree to which people are brought into contact with them. Thus, the impact in one country, or even one area of a country, will not be the same as in another. It depends, among other things, on the level of contamination, the terrain, land use, population density, common economic activities and resources, and the level of development. Impact also varies over time as these factors change. Yet, in any case the effects of cluster munition use are immediate, and the resulting contamination makes these effects long lasting and deep. This report examines the immediate and long-term humanitarian and socio-economic impact of cluster contamination on civilian populations. It draws on a wide range of sources, including case studies from Cambodia and Lebanon, information gathered from practitioners and documentation from contaminated countries, to present an overview of the ways in which such contamination affects the daily lives, opportunities and prospects of ordinary people" -- p. [4] of cover.

• Introduction
• Education, training, and experience
• Leadership competencies
• Leadership actions: the Hump airlift operations
• Leadership actions: the Berlin airlift
• Summary and critique
• Conclusion.

• Palabras del ciudadano general en jefe del ejército Raúl Isaías Baduel
• Palabras del ciudadano general en jefe del ejército (Ej) Gustavo Reyes Rangel Briceño, Ministro del Poder Popular para la Defensa
• Palabras del ciudadano comandante Hugo Chávez, presidente de la República Bolivariana de Venezuela, comandante en jefe de la Fuerza Armada Nacional.

• pt. I. Introduction
• pt. II. The evolution of state biological weapons programs
• pt. III. Evolution of nonstate actor/terrorist biological weapons capabilities
• pt. IV. Framing "the threat" and setting the agenda of public perception and policy prescription
• pt. V. Costs and consequences of the U.S. biodefense program
• pt. VI. Conclusion.

It is nearly 15 years since biological weapons (BW) have become a significant national security preoccupation. The events of September 11, 2001, although not in any way related to BW, combined with the distribution of professionally prepared anthrax spores through the U.S. postal system in the weeks afterwards, magnified previous concerns by orders of magnitude.

• Naval aviation in crisis
• Seaplanes and strategy
• Carrier Conundrum
• Seaplane reborn
• Designs
• SeaMaster
• New look, new missions
• Toward an operational force
• End of the line.

Under the direction of the U.S. Army's Chemical Materials Agency (CMA) and mandated by Congress, the nation is destroying its chemical weapons stockpile. Over the past several years, the Army has requested several studies from the NRC to assist with the stockpile destruction. This study was requested to advise the CMA about the status of analytical instrumentation technology and systems suitable for monitoring airborne chemical warfare agents at chemical weapons disposal and storage facilities. The report presents an assessment of current monitoring systems used for airborne agent detection at CMA facilities and of the applicability and availability of innovative new technologies. It also provides a review of how new regulatory requirements would affect the CMA's current agent monitoring procedures, and whether new measurement technologies are available and could be effectively incorporated into the CMA's overall chemical agent monitoring strategies.
(source: Nielsen Book Data)

On August 14, 1960, a revolution quietly occurred in the reconnaissance capabilities of America. When the Air Force C-119 Flying Boxcar Pelican 9 caught a bucket returning from space with film from a satellite, the American intelligence community gained access to previously denied information about the Soviet Union. The Corona reconnaissance satellite missions that followed lifted the veil of secrecy from the communist bloc, revealing, among other things, that no "Missile Gap" existed. This revolution in military intelligence could not have occurred without the development of the command and control systems that made the Space Race possible. In Spying from Space, David Christopher Arnold tells the story of how military officers and civilian contractors built the Air Force Satellite Control Facility (AFSCF) to support the National Reconnaissance Program. The AFSCF also had a unique relationship with the National Reconnaissance Office, a secret organization that the U.S. government officially concealed as late as the 1990s. Spying from Space fills a gap in space history by telling the story of the command and control systems that made rockets and satellites useful. Those interested in space flight or intelligence efforts will benefit from this revealing look into a little-known aspect of American achievement.
(source: Nielsen Book Data)

• 1915-1918
• Balloon racing resumes
• Lost in Canada
• "Let go!"
• Enter the rigids
• Thomas Greenhow Williams Settle
• Another Navy race
• Lightning and thunder
• The graf Zeppelin
• 1929
• Akron and Macon
• The big win
• Highest aloft
• Finis for the rigids
• Farewell to racing
• 1935-1941
• World War II
• Postwar.

• I. Introduction
• II. The ideal counterforce capability
• III. The revolution in accuracy
• IV. Implications of stealth for counterforce targeting
• V. Solving the challenge of hardened deeply buried targets
• VI. Solving the challenge of targeting mobile missile launchers
• VII. U.S. scud hunt needs and shortfalls
• VIII. Solving the challenge of targeting WMD assets: thermobaric (TB) and agent defeat weapons (ADWs)
• IX. Counterforce science and technology report
• X. Counterforce targeting planning tools
• XI. Counterforce employment and preemption decisions
• XII. Counterforce: the way ahead.

• 1 Front Matter
• 2 Executive Summary
• 3 1. Introduction to Combining Information
• 4 2. Examples of Combining Information
• 5 3. Combining Information in Practice
• 6 4. Prerequisites for Combining Information
• 7 5. Testing Challenges and Opportunities Posed by the Future Combat System
• 8 References
• 9 Appendix A: Further Details Concerning the Bearing Cage Example
• 10 Appendix B: Technical Details on Combining Information in Estimation: A Treatment of Separate Failure Modes
• 11 Appendix C: The Rocket Development Program
• 12 Appendix D: Acronyms and Abbreviations
• 13 Phase I Report: Operational Test Design and Evaluation of the Interim Armored Vehicle
• 14 Biographical Sketches of Panel Members and Staff.
• (source: Nielsen Book Data)

The U.S. Army Test and Evaluation Command (ATEC) is responsible for the operational testing and evaluation of Army systems in development. ATEC requested that the National Research Council form the Panel on Operational Test Design and Evaluation of the Interim Armored Vehicle (Stryker). The charge to this panel was to explore three issues concerning the IOT plans for the Stryker/SBCT. First, the panel was asked to examine the measures selected to assess the performance and effectiveness of the Stryker/SBCT in comparison both to requirements and to the baseline system. Second, the panel was asked to review the test design for the Stryker/SBCT initial operational test to see whether it is consistent with best practices. Third, the panel was asked to identify the advantages and disadvantages of techniques for combining operational test data with data from other sources and types of use. In a previous report (appended to the current report) the panel presented findings, conclusions, and recommendations pertaining to the first two issues: measures of performance and effectiveness, and test design. In the current report, the panel discusses techniques for combining information.
(source: Nielsen Book Data)

• 1 Front Matter
• 2 Executive Summary
• 3 1 Introduction
• 4 2 Technology Alternatives
• 5 3 Power System Design
• 6 4 Soldier Energy Sinks
• 7 5 Progress
• 8 6 Future Warrior Design Concepts
• 9 7 Recommendations
• 10 References
• 11 Appendix A: Biographical Sketches of Committee Members
• 12 Appendix B: Committee Meetings and Other Activities
• 13 Appendix C: Measures of Performance
• 14 Appendix D: Source Technologies.
• (source: Nielsen Book Data)

The central characteristic of the evolution of the combat soldier in recent years is an increasingly sophisticated array of sensing, communications, and related electronics for use in battlefield situations. The most critical factor for maintaining this evolution will be the development of power supply systems capable of operating those electronics effectively for missions up to 72 hours long. To address the challenge, it is important that new approaches be sought on how to integrate and power these electronics. To assist in addressing this problem, the Army requested the National Research Council to review the state of the art and to recommend technologies that will support the rapid development of effective power systems for the future warrior. This report presents the results of that review. It provides an assessment of various technology options for different power level requirements, power system design, and soldier energy sinks. The report also describes future design concepts, focusing on low-power systems. Recommendations for technology development and system design are presented.
(source: Nielsen Book Data)

• Introduction
• Current United States system : an overview
• Lessons learned from the study of potential agents of agricultural bioterrorism
• Research needs and opportunities
• Strengthening the nation's defense against agricultural bioterrorism.

Public confidence in the security of the US food and fiber system has been sustained by the quality, variety, abundance, and affordability of agricultural products in the United States. Although the system in place to defend against unintentional threats to agriculture has weaknesses and needs, the demonstrated ability of the system to resolve, accommodate, or manage critical food safety problems, temporary shortages of some commodities, plant and animal infestations and diseases, and natural disasters indicates that, in general, such confidence has been warranted. However, over the last several years, there has been recognition of the possibility and consequences of intentional threats directed at US agriculture. Such attacks could come from foreign or domestic terrorists and use biological, chemical, or radiological agents. They could be directed at the pre harvest (live plant and live animal) or post harvest (processing and distribution) stages of food and fiber production. "Countering Agricultural Bioterrorism" asseses the vulnerability of US agriculture to intentional threats and provides recommendations needed to strengthen and adapt the US system for defense against biological threats to agriculture.
(source: Nielsen Book Data)

• 1 Front Matter
• 2 Executive Summary
• 3 1 Introduction
• 4 2 National Security Environments and the Context for Landmines
• 5 3 Current Uses of Antipersonnel Landmines
• 6 4 Evaluation Methodology
• 7 5 Alternatives Available Today
• 8 6 Alternatives Available by 2006
• 9 7 Alternatives Potentially Available After 2006
• 10 8 Conclusions and Recommendations
• 11 References
• 12 Appendix A: Biographical Sketches of Committee Members
• 13 Appendix B: Committee Meetings
• 14 Appendix C: Current Types of U.S. Landmines
• 15 Appendix D: Value of Antipersonnel Landmines in Unprotected Mixed Minefields
• 16 Appendix E: The Ottawa Convention and Amended Protocol II of the Convention on Conventional Weapons
• 17 Appendix F: Signatories to the Ottawa Convention and Their Alternatives to Landmines
• 18 Appendix G: Mission Need Statements.
• (source: Nielsen Book Data)

This book examines potential technologies for replacing antipersonnel landmines by 2006, the U.S. target date for signing an international treaty banning these weapons. Alternative Technologies to Replace Antipersonnel Landmines emphasizes the role that technology can play to allow certain weapons to be used more selectively, reducing the danger to uninvolved civilians while improving the effectiveness of the U.S. military. Landmines are an important weapon in the U.S. militarya (TM)s arsenal but the persistent variety can cause unintended casualties, to both civilians and friendly forces. New technologies could replace some, but not all, of the U.S. militarya (TM)s antipersonnel landmines by 2006. In the period following 2006, emerging technologies might eliminate the landmine totally, while retaining the necessary functionalities that todaya (TM)s mines provide to the military.
(source: Nielsen Book Data)

• The origins of the chemical and biological warfare program
• Project Coast, 1981-1993
• Rollback of Project Coast, 1988-1994
• Transition to ANC rule, proliferation concerns and efforts to conceal Project Coast details, 1994-1996
• Basson's arrest and trial and TRC hearings, 1997-2000.

At the start of the 20th century the United States led the world in advances in aviation, with the first successful engine-powered flights at Kitty Hawk, North Carolina, and Dayton, Ohio, beginning in 1903. Fifteen years later, however, American airmen flew European-designed aircraft because American planes were woefully inadequate for services on the Western Front. Why was the United States so poorly prepared to engage in aerial combat in World War II? To answer this question, Herbert Johnson takes a hard look at the early years of US military aviation, exploring the cultural, technical, political and organizational factors that stunted its evolution. Among the recurring themes of Johnson's narrative are the damaging effects of a chronic lack of governmental funding for military aeronautics and the disruptive influence of a civilian ""aeronaut constituency"" both on military discipline and on public Congressional attitudes toward army aviation. In addition, the Wright brothers' patent litigation hindered the technical development of American aircraft and crippled the domestic aviation industry's manufacturing capacity. Wartime experience helped correct some of these problems, but the persistence of others left the postwar Air Service with an uncertain and stormy future.
(source: Nielsen Book Data)

• 1. Air power in the age of total war
• 2. The birth of air power
• 3. The First World War 1914-1918
• 4. The development of air power doctrine and theory 1918-1939
• 5. Global air power 1918-1939
• 6. The war in Europe 1939-1945
• 7. The war in the Far East 1937-1945
• 8. Air power and the post-war world
• 9. Conclusions Bibliography Index.
• (source: Nielsen Book Data)

A fascinating study of the changing military role of air power in the twentieth century, this book examines the sensational impact of the Great War, the pioneering work of air power theorists and visionaries in the interwar period, the air arms race, the SecondWorld War in Europe and the Far East, and finally, the post-war period.
(source: Nielsen Book Data)

• 1 Front Matter
• 2 Executive Summary
• 3 Part I Problem Definition and Status of the Aging Force
• 4 Part II Recommended Strategy and Opportunities for Near-Term and Long-Term Research
• 5 References
• 6 Appendix A: Synopses of Air Force Aging Aircraft Structural Histories
• 7 Appendix B: Biographical Sketches of Committee Members.
• (source: Nielsen Book Data)

Many of the aircraft that form the backbone of the U.S. Air Force operational fleet are 25 years old or older. A few of these will be replaced with new aircraft, but many are expected to remain in service an additional 25 years or more. This book provides a strategy to address the technical needs and priorities associated with the Air Force's aging airframe structures. It includes a detailed summary of the structural status of the aging force, identification of key technical issues, recommendations for near-term engineering and management actions, and prioritized near-term and long-term research recommendations.
(source: Nielsen Book Data)

Another jewel in the growing literature about African-American contributions to aviation has arrived with the release of Double V: The Civil Rights Struggle of the Tuskegee Airmen. Thoroughly researched and punctuated with absorbing personal vignettes, the book is far more than a rehash of the struggles and triumphs of the famed black pilots and crewmen who served in the U.S. Army Air Forces during World War II.... This book is a valuable reference of African-American accomplishments in aviation from World War I through WWII. The depth with which the authors have covered their subject may well be unmatched in any single volume. For everyone interested in examples of the human spirit triumphing over immense obstacles, this book will please and inspire.
(source: Nielsen Book Data)

A study of &lcirc; le aux Noix and other military positions along Quebec's Richelieu River and their defence strategies.
(source: Nielsen Book Data)

Designed for beginners, this is a guide to the collections of aviation records in the Public Record Office. Subjects covered include: aircraft and airships; operational records; organization of the air services; records of individuals; women in the RAF and Air Transport Auxilary; honours and awards; crashes and casualties; and photographic reconnaissance. The records date from the origins of military flying in Britain (1900) to 1964.
(source: Nielsen Book Data)

• Phase 1 - 1950-52
• phase 2 - 1953-60
• phase 3 - 1960-70.
• (source: Nielsen Book Data)

Provides a comprehensive insight into the first 20 years of Royal Air Force helicopter operations, covering their various roles and theatres of operation. The book also describes many of the decisions taken by each of the three services on the future employment patterns of this aircraft type.
(source: Nielsen Book Data)

Some of the most senior commanders of the Royal Air Force are already well-known and have received considerable attention from historians and biographers. Little, however, has been written about most of those who have held the highest appointment the Service has to offer. The 22 biographies in this book include all 19 past Chiefs of the 3 Air Staff and three other very senior commanders. Drawn from a wide cross-section of the nation's talent, their varied careers reflect the history of the Service itself, in war-time as well as in peace-time. This account of the careers and achievements of some of the most outstanding men in the Service is based on Air Commodore Henry Probert's research in the extensive archives of the RAF's Air Historical Branch and on interviews with many of the commanders themselves. Each had to face different challenges and differing circumstances, from fighting for and building an air force, to leading that force in war and then preserving it, and this book shows how these distinctive individuals not only foresaw the potential of air power but enabled it to be realized to the full.
(source: Nielsen Book Data)

From his beginning as Bill Hooper's personal cartoon "doodle" decorating the wall of "A" Flight's hut, the affable dimwit known as Pilot Officer Prune served right through the war, was posted to every command and even found himself "Out East". The little Spitfire pilot became the first example of a visual aid for technical training, showing thousands of aircrew all over the world how not to do it. In this book his creator Bill Hooper and Tim Hamilton trace the life and times of the plum nose character who proved such a successful anti-hero with the RAF and who doubtless saved many lives. Using drawings from the period, Bill Hooper's anecdotes and wherever possible original documents, this book should appeal to those with a keen interest in the RAF or aviation, or those who appreciate the humour of this cartoon character.
(source: Nielsen Book Data)

On 19 July 1919 a great Victory Parade was held in London. The Tank Corps was represented by some 70 men and four Medium C tanks. Tanks had first seen action on 15 September 1916 and their progress since then had been astounding. However, the Allied victory in Europe was no guarantee of a peaceful world and there was still a place for armoured vehicles. Although the Tank Corps was substantially reduced in the inter-war years, the machines were continually being developed. With very little past experience to guide them but massive technological strides to carry them on their way, the designers had free rein. "Merchanised Force" is a history of the Tank Corps from 1919 up until the time when, as the Royal Tank Regiment, it went to war again in 1939. It chronicles the many exciting events and innovations of the years between the wars, the truly formative years of tank design.
(source: Nielsen Book Data)

The air force made a huge impact on the events of World War II, but this new force of men and machines did not simply appear out of the blue. There was a long history leading up to the use of air power in military campaigns. When Franklin D. Roosevelt entered the White House in 1933, the leaders of the Army Air Corps wanted to force him, Congress, and the Army General Staff to create an independent air force. Using Billy Mitchell's tactics of public confrontation, exploitation of the air corps's poor condition, and unproven claims about air power, these officers only antagonized the people who could grant them independence. After the air corps failed to carry the air mail in 1934, a number of air corps officers started a concerted effort to promote themselves as "team players" who had given up the caustic, separatist attitudes of Mitchell. By the beginning of World War II, they had convinced Roosevelt, Congress, and the General Staff of the air corps's efficiency, as evidenced by Roosevelt's air corps expansion programs and the army's war plans. After the war in Europe substantiated many of the claims about air power, especially the ability of land-based airplanes to force unprotected naval forces to withdraw, Roosevelt and his military advisors placed increasing emphasis on the role of the air corps. Jeffery S. Underwood's book moves away from the traditional studies of air power. By examining how the leading officers in the air corps developed political skills and used them to win the trust and support of their superiors, it shows that the political and military leaders of the United States were not suddenly forced to accept the importance of air power by the war in Europe. Rather, they had already been awakened to the potential of air power by the efforts of politically astute air corps officers.
(source: Nielsen Book Data)

• Modern robust control for missile autopilot design / R. T. Reichert, D. J. Yost
• Midcourse guidance techniques for advanced tactical missile systems / U. Hartmann
• Flight control design issues in bank-to-turn missiles / W. A. Kaufmann
• Guidance simulation model of anti sea-skimmer missile / F. Burel
• Advanced missile guidance / R. V. Lawrence
• Micro based technology : a new tool for missile guidance system design and visualization / P. Zarchan
• Interactions between battle management and guidance law design for a strategic interceptor / O. L. Deutsch
• Guidance methods for tactical and strategic missiles / P. Zarchan.

This book records the recovery vehicles, trailers and tank transporters operated by the British Army since mechanical transport was first adopted, and not only lists and describes the vehicles themselves but sets their developments, acquisition and use against the contemporary background in both war and peace. The book shows that not until World War II was it fully appreciated that the retrieval and repair of damaged equipment from the battlefield could make a significant impact on the costs and logistics of war. The book is illustrated with some previously unpublished photographs - including some experimental vehicles never portrayed before - and should appeal not only to all military transport enthusiasts and modellers but also to those interested in the civil development of heavy vehicles.
(source: Nielsen Book Data)