Please answer the following question: Information:  - Alternating current (AC), is an electric current which periodically reverses polarity, whereas direct current (DC, also dc) flows only in one direction with a single polarity either positive or negative. Alternating current is the form in which electric power is delivered to businesses and residences, and it is the form of electric energy that consumers typically use when they plug kitchen appliances, televisions and electric lamps into a wall socket. A common source of DC power is a battery cell in a flashlight. The abbreviations "AC" and "DC" are often used to mean simply "alternating" and "direct", as when they modify "current" or "voltage".  - Germany, officially the Federal Republic of Germany, is a federal parliamentary republic in central-western Europe. It includes 16 constituent states, covers an area of , and has a largely temperate seasonal climate. With about 82 million inhabitants, Germany is the most populous member state of the European Union. After the United States, it is the second most popular immigration destination in the world. Germany's capital and largest metropolis is Berlin. Other major cities include Hamburg, Munich, Cologne, Frankfurt, Stuttgart and Düsseldorf.  - Trade, or commerce, involves the transfer of goods and/or services from one person or entity to another, often in exchange for money. A network that allows trade is called a market.  - Hamburg (local pronunciation ; Low German/Low Saxon: "Hamborg" ), officially "Freie und Hansestadt Hamburg" (Free and Hanseatic City of Hamburg), is the second largest city in Germany and the eighth largest city in the European Union. It is the second smallest German state by area. Its population is over 1.7 million people, and the wider Hamburg Metropolitan Region covers more than 5.1 million inhabitants. The city is situated on the river Elbe.  - Frequency is the number of occurrences of a repeating event per unit time. It is also referred to as temporal frequency, which emphasizes the contrast to spatial frequency and angular frequency. The period is the duration of time of one cycle in a repeating event, so the period is the reciprocal of the frequency. For example, if a newborn baby's heart beats at a frequency of 120 times a minute, its periodthe time interval between beatsis half a second (that is, 60 seconds divided by 120 beats). Frequency is an important parameter used in science and engineering to specify the rate of oscillatory and vibratory phenomena, such as mechanical vibrations, audio (sound) signals, radio waves, and light.  - Stuttgart ( Swabian: "Schduagert"), often nicknamed the ""Schwabenmetropole"" in reference to its location in the center of Swabia and the local dialect spoken by some natives, is the capital and largest city of the German state of Baden-Württemberg. It is located on the Neckar river in a fertile valley locally known as the "Stuttgarter Kessel" an hour from the Swabian Jura and the Black Forest. Stuttgart's name comes from the Old High German word ""Stuogarten"," or "stud farm"  a reference to the city's founding in 950 AD as a stud farm. Stuttgarts urban area has a population of 623,738, and a further making it the sixth largest city in Germany, 2.7 million people live in the citys administrative region, and another 5.3 million people in its metropolitan area, making it the fourth largest metropolitan area in Germany.  - Berlin is the capital and the largest city of Germany as well as one of its constituent 16 states. With a population of approximately 3.5 million people, Berlin is the second most populous city proper and the seventh most populous urban area in the European Union. Located in northeastern Germany on the banks of rivers Spree and Havel, it is the centre of the Berlin-Brandenburg Metropolitan Region, which has about 6 million residents from more than 180 nations. Due to its location in the European Plain, Berlin is influenced by a temperate seasonal climate. Around one-third of the city's area is composed of forests, parks, gardens, rivers and lakes.  - Bremerhaven (literally "Bremen's harbour", Low German: "Bremerhoben") is a city at the seaport of the Free Hanseatic City of Bremen, a state of the Federal Republic of Germany. It forms an enclave in the state of Lower Saxony and is located at the mouth of the River Weser on its eastern bank, opposite the town of Nordenham. Though a relatively new city, it has a long history as a trade port and today is one of the most important German ports, playing a crucial role in Germany's trade.  - A port is a location on a coast or shore containing one or more harbors where ships can dock and transfer people or cargo to or from land. Port locations are selected to optimize access to land and navigable water, for commercial demand, and for shelter from wind and waves. Ports with deeper water are rarer, but can handle larger ships. Since ports throughout history handled every kind of traffic, support and storage facilities vary widely, may extend for miles, and dominate the local economy. Some ports have an important military role.  - A tower is a tall structure, taller than it is wide, often by a significant margin. Towers are distinguished from masts by their lack of guy-wires and are therefore, along with tall buildings, self-supporting structures.  - Reinforced concrete (RC) is a composite material in which concrete's relatively low tensile strength and ductility are counteracted by the inclusion of reinforcement having higher tensile strength or ductility. The reinforcement is usually, though not necessarily, steel reinforcing bars (rebar) and is usually embedded passively in the concrete before the concrete sets. Reinforcing schemes are generally designed to resist tensile stresses in particular regions of the concrete that might cause unacceptable cracking and/or structural failure. Modern reinforced concrete can contain varied reinforcing materials made of steel, polymers or alternate composite material in conjunction with rebar or not. Reinforced concrete may also be permanently stressed (in compression), so as to improve the behaviour of the final structure under working loads. In the United States, the most common methods of doing this are known as pre-tensioning and post-tensioning. For a strong, ductile and durable construction the reinforcement needs to have the following properties at least:  - The City Municipality of Bremen is a Hanseatic city in northwestern Germany, which belongs to the state Free Hanseatic City of Bremen (also called just "Bremen" for short).  - Technology ("science of craft", from Greek , "techne", "art, skill, cunning of hand"; and , "-logia") is the collection of techniques, skills, methods and processes used in the production of goods or services or in the accomplishment of objectives, such as scientific investigation. Technology can be the knowledge of techniques, processes, and the like, or it can be embedded in machines which can be operated without detailed knowledge of their workings.  - A parliamentary republic is a republic that operates under a parliamentary system of government where the executive branch (the government) derives its legitimacy from and is accountable to the legislature (the parliament). There are a number of variations of parliamentary republics. Most have a clear differentiation between the head of government and the head of state, with the head of government holding real power, much like constitutional monarchies. Some have combined the roles of head of state and head of government, much like presidential systems, but with a dependency upon parliamentary power.  - The amplitude of a periodic variable is a measure of its change over a single period (such as time or spatial period). There are various definitions of amplitude (see below), which are all functions of the magnitude of the difference between the variable's extreme values. In older texts the phase is sometimes called the amplitude.  - Nordenham is a town in the Wesermarsch district, in Lower Saxony, Germany. It is located at the mouth (on the west bank) of the Weser river on the Butjadingen peninsula on the coast of the North Sea. The seaport city of Bremerhaven is located on the other side (east bank) of the river. The Midgard-seaport in Nordenham is the largest private-owned harbor in Germany.  - Radio is the technology of using radio waves to carry information, such as sound, by systematically modulating properties of electromagnetic energy waves transmitted through space, such as their amplitude, frequency, phase, or pulse width. When radio waves strike an electrical conductor, the oscillating fields induce an alternating current in the conductor. The information in the waves can be extracted and transformed back into its original form.  - Steel is an alloy of iron and other elements, primarily carbon, that is widely used in construction and other applications because of its high tensile strength and low cost. Steel's base metal is iron, which is able to take on two crystalline forms (allotropic forms), body centered cubic and face centered cubic (FCC), depending on its temperature. It is the interaction of those allotropes with the alloying elements, primarily carbon, that gives steel and cast iron their range of unique properties. In the body-centred cubic arrangement, there is an iron atom in the centre of each cube, and in the face-centred cubic, there is one at the center of each of the six faces of the cube. Carbon, other elements, and inclusions within iron act as hardening agents that prevent the movement of dislocations that otherwise occur in the crystal lattices of iron atoms.  - Cologne is the largest city in the German federal State of North Rhine-Westphalia and the fourth-largest city in Germany (after Berlin, Hamburg, and Munich). It is located within the Rhine-Ruhr metropolitan region, one of the major European metropolitan regions and the largest in Germany, with more than ten million inhabitants.  - The European Union (EU) is a political and economic union of member states that are located primarily in Europe. It has an area of , and an estimated population of over 510 million. The EU has developed an internal single market through a standardised system of laws that apply in all member states. EU policies aim to ensure the free movement of people, goods, services, and capital within the internal market, enact legislation in justice and home affairs, and maintain common policies on trade, agriculture, fisheries, and regional development. Within the Schengen Area, passport controls have been abolished. A monetary union was established in 1999 and came into full force in 2002, and is composed of 19 EU member states which use the euro currency.  - Lower Saxony is a German state ("Bundesland") situated in northwestern Germany and is second in area, with , and fourth in population (8 million) among the sixteen "Länder" of Germany. In rural areas Northern Low Saxon, a dialect of Low German, and Saterland Frisian, a variety of Frisian, are still spoken, but the number of speakers is declining.  - Radio waves are a type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light. Radio waves have frequencies as high as 300 GHz to as low as 3 kHz, though some definitions describe waves above 1 or 3 GHz as microwaves, or include waves of any lower frequency. At 300 GHz, the corresponding wavelength is , and at 3 kHz is . Like all other electromagnetic waves, they travel at the speed of light. Naturally occurring radio waves are generated by lightning, or by astronomical objects.   - The euro (sign: €; code: EUR) is the official currency of the eurozone, which consists of 19 of the member states of the European Union: Austria, Belgium, Cyprus, Estonia, Finland, France, Germany, Greece, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Portugal, Slovakia, Slovenia, and Spain. The currency is also officially used by the institutions of the European Union and four other European countries, as well as unilaterally by two others, and is consequently used daily by some 337 million Europeans . Outside of Europe, a number of overseas territories of EU members also use the euro as their currency.  - A polymer (Greek "poly-", "many" + "-mer", "parts") is a large molecule, or macromolecule, composed of many repeated subunits. Because of their broad range of properties, both synthetic and natural polymers play an essential and ubiquitous role in everyday life. Polymers range from familiar synthetic plastics such as polystyrene to natural biopolymers such as DNA and proteins that are fundamental to biological structure and function. Polymers, both natural and synthetic, are created via polymerization of many small molecules, known as monomers. Their consequently large molecular mass relative to small molecule compounds produces unique physical properties, including toughness, viscoelasticity, and a tendency to form glasses and semicrystalline structures rather than crystals.  - The Weser is a river in Northwestern Germany. Formed at Hannoversch Münden by the confluence of the rivers Fulda and Werra, it flows through Lower Saxony, then reaching the Hanseatic-town Bremen (see: Hanseatic League), before emptying further north at Bremerhaven into the North Sea. On the opposite (west) bank is the town of Nordenham at the foot of the Butjadingen Peninsula; thus, the mouth of the river is in Lower Saxony. The Weser has an overall length of . Together with its Werra tributary, which originates in Thuringia, its length is .  - Concrete is a composite material composed of coarse aggregate bonded together with a fluid cement that hardens over time. Most concretes used are lime-based concretes such as Portland cement concrete or concretes made with other hydraulic cements, such as ciment fondu. However, asphalt concrete, which is frequently used for road surfaces, is also a type of concrete, where the cement material is bitumen, and polymer concretes are sometimes used where the cementing material is a polymer.  - Europe is a continent that comprises the westernmost part of Eurasia. Europe is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, and the Mediterranean Sea to the south. To the east and southeast, Europe is generally considered as separated from Asia by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways of the Turkish Straits. Yet the non-oceanic borders of Europea concept dating back to classical antiquityare arbitrary. The primarily physiographic term "continent" as applied to Europe also incorporates cultural and political elements whose discontinuities are not always reflected by the continent's current overland boundaries.  - The Bremerhaven Radar Tower is a 106 metre reinforced concrete tower located in Bremerhaven , Germany . The radar tower , which was constructed between 1962 and 1965 , accommodates numerous transmitting plants for maritime radio purposes , in addition to its radar equipment . A viewing platform is situated at the 60 metre level , and is accessible to the public . Unlike other transmitting towers , the Bremerhaven facility belongs to the Bremerhaven Water and Shipping department and not Deutsche Telekom AG or a broadcasting corporation .  - Frankfurt am Main is a metropolis and the largest city in the German state of Hesse and the fifth-largest city in Germany, with a 2015 population of 731,095 within its administrative boundaries, and 2.3 million in its urban area. The city is at the centre of the larger Frankfurt Rhine-Main Metropolitan Region, which has a population of 5.8 million and is Germany's second-largest metropolitan region after Rhine-Ruhr. Since the enlargement of the European Union in 2013, the geographic centre of the EU is about to the east of Frankfurt's CBD, the Bankenviertel. Frankfurt is culturally and ethnically diverse, with around half of the population, and a majority of young people, having a migration background. A quarter of the population are foreign nationals, including many expatriates.  - Low German or Low Saxon ( or in the wider sense) is a West Germanic language spoken mainly in northern Germany and the eastern part of the Netherlands. It is descended from Old Saxon in its earliest form.  - A republic (from ) is a sovereign state, country, or government which is organized with a form of government in which power resides in elected individuals representing the citizen body and government leaders exercise power according to the rule of law. In modern times, the definition of a republic commonly refers to a government which excludes a monarch. Currently, 147 of the world's 206 sovereign states use the word "republic" as part of their official names; not all of these are republics in the sense of having elected governments, nor do all nations with elected governments use the word "republic" in their names.  - In materials science, ductility is a solid material's ability to deform under tensile stress; this is often characterized by the material's ability to be stretched into a wire. Malleability, a similar property, is a material's ability to deform under compressive stress; this is often characterized by the material's ability to form a thin sheet by hammering or rolling. Both of these mechanical properties are aspects of plasticity, the extent to which a solid material can be plastically deformed without fracture. Also, these material properties are dependent on temperature and pressure (investigated by Percy Williams Bridgman as part of his Nobel Prize-winning work on high pressures).  - Düsseldorf (Low Franconian, Ripuarian: "Düsseldörp" ) is the capital city of the German state of North Rhine-Westphalia and the seventh most populous city in Germany. Düsseldorf is an international business and financial centre, renowned for its fashion and trade fairs. The city is headquarters to one Fortune Global 500 and two DAX companies. Messe Düsseldorf organises nearly one fifth of premier trade shows.  - Rebar (short for reinforcing bar), collectively known as reinforcing steel and reinforcement steel, is a steel bar or mesh of steel wires used as a tension device in reinforced concrete and reinforced masonry structures to strengthen and hold the concrete in tension. Rebar's surface is often patterned to form a better bond with the concrete.  - Information is that which informs. In other words, it is the answer to a question of some kind. It is thus related to data and knowledge, as data represents values attributed to parameters, and knowledge signifies understanding of real things or abstract concepts. As it regards data, the information's existence is not necessarily coupled to an observer (it exists beyond an event horizon, for example), while in the case of knowledge, the information requires a cognitive observer.  - A cement is a binder, a substance used in construction that sets and hardens and can bind other materials together. The most important types of cement are used as a component in the production of mortar in masonry, and of concrete, which is a combination of cement and an aggregate to form a strong building material.  - A building or edifice is a structure with a roof and walls standing more or less permanently in one place, such as a house or factory. Buildings come in a variety of sizes, shapes and functions, and have been adapted throughout history for a wide number of factors, from building materials available, to weather conditions, to land prices, ground conditions, specific uses and aesthetic reasons. To better understand the term "building" compare the list of nonbuilding structures.  - Munich (also in British English ) is the capital and largest city of the German state of Bavaria, on the banks of River Isar north of the Bavarian Alps. Munich is the third largest city in Germany, after Berlin and Hamburg, and the 12th biggest city of the European Union, with a population of above 1.5 million. The Munich Metropolitan Region is home to 5.8 million people.  - In physics and electrical engineering, a conductor is an object or type of material that allows the flow of an electrical current in one or more directions. A metal wire is a common electrical conductor. Electrical current is generated by the flow of negatively charged electrons, positively charged holes, and positive or negative ions in some cases.   - In physics, energy is the property that must be transferred to an object in order to perform work on  or to heat  the object, and can be converted in form, but not created or destroyed. The SI unit of energy is the joule, which is the energy transferred to an object by the mechanical work of moving it a distance of 1 metre against a force of 1 newton.    What entity does 'bremerhaven radar tower' has the relation 'located in the administrative territorial entity' with?
A:
bremen