Compact Placement Research Articles

The method of efficient individual control of electric traction motors of an electric portal axle during cornering

BACKGROUND: In recent years, the global automotive industry has shown increased interest in electric traction drive for road vehicles, including electric cars, electric buses and electric trucks, where various drive layouts are used. One of the most widespread drive layouts is an individual electric traction drive, which is often used in modern electric buses. The individual electric traction drive has such advantages as reliability in sustaining traction or braking forces in case of failure of one of the engines, compact placement of engines, low floor level along the entire length of the cabin and adaptation of the electric traction drive to road conditions. The last point of the mentioned advantages requires the development of an advanced control system. AIMS: Development of the yaw recognition algorithm and formation of the algorithm for designing a torque redistribution regulator. METHODS: Modeling of the operation of the yaw recognition algorithm is carried out during simulation tests in the MATLAB/Simulink software package. The main dependencies are derived, followed by obtaining a phase variable, for the correct operation of the optimal controller. RESULTS: The yaw recognition algorithm, which forms the torque redistribution between the driving wheels, is developed, an algorithm for designing an optimal regulator was developed, such concepts as theoretical and actual motion parameters are introduced. Simulation modeling of the spatial movement of an electric bus is carried out in the MATLAB/Simulink software package, showing the operability and efficiency of the developed system. The scientific novelty is the formation of the optimal regulator, making torque redistribution possible. CONCLUSIONS: The practical value of the development and research lies in the possibility of applying the algorithm and the control law for vehicles equipped with the individual electric traction drive.

Система расселения Калининградской области: дазиметрический анализ

The article examines the settlement system of the Kaliningrad region using the dasymet­ric method, first proposed in the early 20th century by the Russian geographer V. P. Se­menov-Tyan-Shansky as a more precise alternative to population density cartograms. Several dasymetric analysis approaches (buffer zone delineation and grid methods) of the settlement system and mapping of the territory in the Kaliningrad Oblast are demonstrated using GIS tools. Areas of the highest population concentration within the region, coinciding with the agglomeration's influence territory, have been identified. A decrease in population density to the east of Kaliningrad is also shown. For the municipal entities of the Kaliningrad region, the area and density of inhabited territories have been calculated. Dasymetric analysis has re­vealed areas of compact placement of rural settlements, aligning with the designated govern­ment rural agglomerations. The conclusion is drawn regarding the existence of stronger con­nections between settlements within different municipal entities and the potential for the ex­pansion of rural agglomerations beyond administrative boundaries. The connectivity of rural and urban settlements within the boundaries of the Kaliningrad agglomeration suggests the formation of second-order agglomerations. The dasymetric method can be utilized in further research to analyze the settlement system for studying the development of rural territories.

FPGA fabric conscious architecture design and automation of speed-area efficient Margolus neighborhood based cellular automata with variegated scan path insertion

Optimized Field Programmable Gate Array (FPGA) implementation of Cellular Automata (CA) for high speed design requires knowledge of the platform specific logic cell architecture. In this paper, we have proposed architectures and design automation of a particular class of CA, essentially a Finite State Machine (FSM), which obey rules governed by principles of Margolus neighborhood. Under this proposition, the inputs to the next state function of the FSM for every CA cell alternates between two sets of data in every successive clock cycle. Careful choice of logic elements and their compact placement was ensured for speed-area efficient implementation. Variants of scan insertion were carried out for fault localization by properly utilizing the logic cells realizing the original Margolus CA, so that area-delay overhead is minimized. We outperform behavioral or register transfer level (RTL) based descriptions for CA implementations, expressed through conventional higher levels of abstraction, with respect to delay and occupancy count of logic slices.

On‐chip miniaturized bandpass filter using gallium arsenide‐based integrated passive device technology

AbstractThe paper proposes a miniaturized bandpass filter (BPF) using gallium arsenide (GaAs)‐based integrated passive device (IPD) technology. The proposed filter is evolved from traditional third order BPF, and it achieves a wide operation frequency band covering three 5G sub‐bands including 3.4–3.5 GHz, 3.5–3.6 GHz, and 4.8–4.9 GHz. The performance of out‐of‐band rejection is improved by introducing three transmission zeros (TZs). As known, adding cross coupling and LC resonator are the general methods to improve out‐of‐band rejection. Therefore, the first TZ at 5.85 GHz is obtained at the upper sideband by adding a capacitive coupling between the source port and resonator 2, which is a cross‐coupling mode. According to the coupling matrix, the value of the added capacitance can be calculated and optimized. Another TZ at 2.36 GHz is occurred at the left side of passband as a serial LC resonator is connected in parallel with filter near the input port. The third TZ at 7.74 GHz is generated at the upper sideband due to a serial LC resonator connected in parallel with the load terminal of the filter. The values of components in LC resonators can be calculated, too. Finally, the whole filter is optimized in full‐wave electromagnetic simulation software HFSS. The proposed filter is fabricated and measured, and the results show that it has a wide −10 dB frequency band from 3.3 GHz to 4.9 GHz and a maximum insertion loss of 2.5 dB. In addition, it has a good frequency selectivity with a rectangular coefficient of 1.67 and out‐of‐band suppression higher than 20 dB in a wide stopband. The filter adopts compact placement and has a relative miniaturized electrical size of 0.298 , which is about 55% smaller than recently reported one.

Low-power nuclear power plants in the context of electric power systems transformation

Increasing economic importance of the Arctic, further intensification of northern sea routes, and exceptional sensitivity of the arctic natural environment to anthropogenic impacts are fundamental factors for a comprehensive study of environmental aspects in the application of innovative technologies for the development of infrastructure in the Arctic. Despite the growing interest in low-power nuclear power plants as a distributed generation facility, their possible application in technologically isolated power systems does not lose relevance. The development of both the Arctic and Far Eastern regions of the Russian Federation presents great opportunities and demand for the use of nuclear power sources. Also, development programs for the Russian arctic zone imply a significant increase in the role and number of nuclear power facilities, in other words of potential radiation-hazardous facilities. Large-scale use of nuclear-powered installations in the Arctic necessitates advanced development of a scientifically grounded and modern forecasting system as well as assessments of threats and risks in case of possible radiation emergencies at nuclear- and radiation-hazardous facilities. Also, the development of proposals for necessary measures to minimize negative consequences of such emergencies is required. This is especially true for the case of compact placement of industrial, infrastructure and residential facilities in the Arctic in the immediate vicinity of nuclear facilities. The paper demonstrates that the demand for low-power nuclear power plants and their competitiveness will grow steadily in the conditions of electric-power industry decentralization, further spread of distributed generation and the development of technologically isolated power systems. Approaches to the generation of a low nuclear-power system based on the philosophy of industrialization of production and centralized management are presented. Special features of the environmental impact assessment of low-power nuclear power plants for the development of a methodology to study the radio-ecological hazard related problems are provided.

Slotted Resonator Section of the Silencer for Engineering Networks

The paper is devoted to noise reduction in engineering networks. It is indicated that the slotted silencer is promising for systems with large cross-section air ducts and flues. The technological and operational possibilities of including in the silencer the additional slotted section are noted. The additional two-slot section containing Helmholtz resonators is presented. Based on the calculations it was found that broadband noise reduction is provided by tuning the slotted resonators in a geometric progression with a denominator of 20.8. For a section with three resonators in each slot duct the following is shown: the resonator with the highest tuning frequency does not significantly effect the noise reduction of the other two resonators; the resonator with the highest tuning frequency can be placed between resonators with lower tuning frequencies. Compact placement of slotted resonators is proposed. The length of the device is shorted by 1.5 times while reducing the efficiency by 30%. The obtained data show that the silencer section composed from Helmholtz slotted resonators allows fulfilling silencer with additional noise reduction in the frequency range of 31.5-125 Hz and acceptable length.

ТЕХНІЧНІ ЗАСОБИ НАВЧАННЯ І ПІДГОТОВКИ ВІЙСЬК. ОГЛЯД ТЕХНОЛОГІЙ

The article considers the problematic issues concerning the application of the latest training technologies in the training program of the Land Forces, the analysis of their influence on the level of combat training of mechanized and tank units. The problems of integration in the process of combat training of mechanized and tank units of the Land Forces of training means, namely complex training systems, which will provide an effective solution to a wide range of tasks, are considered. The direct influence of educational means on the level of training of personnel is determined. A generalized scheme of classification of training equipment and training and range equipment has been developed, according to which simulators of certain types of weapons and military equipment, as well as simulators of control and communication equipment are combined into a single training and modeling system of tactical training of crews, combat units and military units. A comparative analysis of the effectiveness of classes using traditional training tools and tools based on the latest training technologies. The advantages of the new generation of simulators are substantiated, which allows: to increase the capacity of personnel training; reduce electricity costs; reduce the number of forces and resources involved in training; to provide compact placement of a training complex; to reduce term of training of experts from 4-5 weeks to 2-3 weeks. Keywords: training tools, combat training, computer technology systems, training systems, training technologies.

ЕФЕКТИВНІСТЬ ОДИНИЧНОГО КОДУВАННЯ ДАНИХ

The paper analyzes the implementation properties of unit codes as alternatives to classical binary ones. The possibility of forming a logical-temporal code, which is a symbiosis of two known unit codes: a unit normal and a unit positional (marking) code, is shown. This allows you to provide accelerated principle of recording information and less energy-intensive while storing it. Analytical expressions for calculation of hardware and time expenses at concrete realization of unit data encoding on the shift register and the binary counter with the decoder are resulted. It is the lack of decryption of the generated data that requires increasing the number of connections in the schemes in times. The widespread use of FPGAs eliminates this problem with the compact placement of unit-coded devices in the FPGA chip. This makes it possible to use unit codes as an alternative to binary codes in data transmission, as well as in some types of control devices when encoding their states and in storage devices when addressing their contents. As an example, the efficiency of using unit codes for encoding the states of microprogram automata is shown, which is achieved by the low complexity of combinational circuits and the absence of the need to decode the code combinations of automaton states.

Exploring Multiple Analog Placements With Partial-Monotonic Current Paths and Symmetry Constraints Using PCP-SP

Modern analog placement techniques require consideration of current path and symmetry constraints. The symmetry pairs can be efficiently packed using the symmetry island configurations, but not all these configurations result in minimum gate interconnection, which can impact the overall circuit routing and performance. This article proposes the first work that reformulates this problem considering all of them together in the form of parallel current path (PCP) constraints. PCP constraints, in addition to monotonic current paths, also consider partial-monotonic current paths to generate a more compact placement. We use a novel two-step approach to detect symmetry-feasible sequence-pairs (SFSPs) without doing placement construction by using representative sequence-pair (RSP). Then a placement algorithm satisfying these constraints is formulated to reduce a vast search space via efficient sequence pair manipulation. The experimental results show that this formulation and algorithm can generate multiple placement solutions that satisfy all the constraints in a more tightly packed configuration, resulting in smaller wirelength, reduced parasitics, and thus better post-layout performance.

Impact of relative spacing of two adjacent vertical axis wind turbines on their aerodynamics

The impact of relative spacing on the individual and overall performance of two adjacent co-rotating Darrieus H-type VAWTs is investigated through high-fidelity URANS simulations, validated with experimental data. The simulations cover relative distances of 1.25d ≤ R ≤ 10d (d: turbine diameter) and relative angles of 0° ≤ Φ ≤ 90°. The relative angles of 30° ≤ Φ ≤ 75 with relative distance range of 1.25d ≤ R ≤ 5d are identified as the optimal regime with the highest overall power performance for the array. In this regime, the downstream turbine has a maximum increase of 5.1% in CP (R = 1.5d and Φ = 45°) with respect to an isolated solo rotor with similar characteristics. Local flow characteristics including wake length, wake expansion, vorticity and velocity fields are also investigated. It is found that for azimuthal angles of 90° ≤ θ ≤ 160° in the optimal regime, regions of accelerated flow are created due to the contraction of the flow between the turbines which benefit the downstream turbine CP and thus the overall power performance of the array. This provides an opportunity for a compact placement of turbines within a vertical-axis wind turbine farm and consequently increasing the farm power density.

ТЕХНОЛОГІЧНЕ ОБЛАДНАННЯ НА ПОВІТРЯНИХ ПОДУШКАХ КОВЗАННЯ - ЗАСТОСУВАННЯ В ЛІТАКОБУДУВАННІ. РОЗРАХУНОК ПАРАМЕТРІВ

The technological equipment under consideration relates to air-cushioned out-door vehicles operating from the workshop pneumatic network. Their designs are based on the modular principle. A typical design of such equipment equipped with inflatable balloon fences is presented. The effectiveness of their use in aircraft construction is shown. When performing interoperational movements, they provide savings in production space due to the compact placement of aircraft in assembly shops. When performing mounting and docking operations, the proposed equipment does not require accurate combination of mating units and simplifies the process of docking heavy units. The equipment also allows for cyclic ground tests of a rotary wing of an aircraft with loads close to flight. This eliminates possible emergency situations during flight tests and ensures the safety of expensive products. When performing loading and unloading operations, the use of air cushions allows to reduce the weight of loading equipment, as well as reduce the time and cost of these operations. Most researchers consider the flow to be viscous and laminar due to small flow gaps be-tween the balloon guard and the floor supporting surface. A new approach is pro-posed here. It is based on a turbulent regime of outflow from an air cushion. This is confirmed by replacing the real air path with an equivalent circular section. As a result, the configuration of the outlet channel is transformed into a short confuser diffuser nozzle with a small length along the flow. And such resistances are considered turbulent. As the first turbulent throttle acts as an air flow regulator at the en-trance to the support. Proceeding from this, calculation methods are proposed that allow one to determine expendable, energy, and specific indicators of both individual modules on air cushions and systems based on them. The information necessary for the designer is given to solve current problems in aircraft construction and other are-as of technology.

ДВУХПРУДОВОЙ НАГУЛЬНО-ВЫРОСТНОЙ РЫБОВОДНЫЙ КОМПЛЕКС

Purpose: development and description of the layout and design solution for a two-pond feeding nursery fish-breeding complex, which characterizes by compact placement of its constituent structures and their adaptation to the topographic conditions of the territory. Materials and methods. The theoretical and empirical basis for the development was made up of well-known recommendations on design and construction of pond complexes and survey data of operating fish-breeding facilities and their structures. During the development, the technologies of search design of engineering projects in compliance with fish breeding requirements and restrictions were used. Results. The fish-breeding complex includes: two fish-breeding ponds with a common dividing dam and a water supply system including a pumping station; water supply pipe system; a system of devices and structures that ensure the release of fish grown in ponds into a fish trap; spillway devices for discharging water from ponds and a fish trap with a set of regulating elements. Fish ponds are located on the floodplain lands of the river Don and are formed by protecting dikes. The bed of the reservoirs is planned with sections with longitudinal and transverse slopes to the water-fish collecting and-transporting ditches arranged in their bottom, allowing them to be emptied and the fish grown in the ponds to be directed to the outlet structures. The release of fish from the ponds is carried out by two tower water outlets. The design of the fish trap provides for the accumulation and seine fishing, it is equipped with means for regulating water discharge and maintaining conditions for fish. Conclusions. The developed layout and design solution for a two-pond fish-breeding complex with one fish trap is adapted to the local relief and the difference in water levels in ponds and in water intake. The implemented layout and design solutions can be used in the development of similar objects

Cluster radioactivity: analysis, forecast, new factors of slowing the decay of atomic nuclei

Some regularities of cluster decays are revealed, which make it possible to predict the existence of a large number of medium, heavy and, possibly, superheavy f-active nuclei. The stability of the majority of non-magic nuclides (products of cluster radioactivity) is explained by the simultaneous action of the already known factors slowing (stabilizing) the radioactive decays of atomic nuclei and some additional factors. Among the additional factors, a weakly expressed effect of pairing of α-particles in light nuclei can be noted. In some cases, an additional particle (neutron, proton or light cluster) contributes to the stability of the nucleus by intensifying the forces of mutual nuclear attraction. Compact arrangement of α-clusters in another additional factor stabilizing the nuclei. One more factor is associated with compact placement of neutrons (possibly paired) between α-clusters within the of light nuclei.

Чисельне моделювання теплообмінного апарата для різних систем вентиляції

The purpose of the research is to develop and numerical modeling of the shell-tube heat exchanger of a new design as an element of the microclimate maintenance system for various types of ventilation systems in the summer season. Materials and methods of research. As mentioned above, two types of ventilation systems are considered - tunnel and lateral. For these ventilation systems TA is projected. The poultry house is a traditional type. At the side walls there are openings with jackets in the total number of 80 pieces. with dimensions 0,3×0,85 m. And also on the front end walls are located evacuation cooling tapes with dimensions of 5,1×1,1 m. In place of the cassettes and louver we fit the HE. Consider the shell and tube heat exchanger with a shell of a rectangular cross section in the transverse flow of pipe beams. The geometry of the pipes with diameters d = 10 mm is peculiar, which differs from the traditional chess, corridor and compact beams. Neighboring pipes in such close beams are displaced one relative to the other at a distance of 1 mm. Moreover, we consider two types of beam construction, in which there is a displacement of pipes in a transverse direction along the entire length of the tube beam by 15 mm. All calculations are performed at a volume flow of air 1036 thousand m3/h. As a coolant air is selected with a temperature of +40 o С at the inlet, which flows in the channels for cooling the external heated air in the poultry house in the summer period of the year, where as the cooler is used water underground wells. In the soybean, cold water moving inside the pipes, which has an inlet temperature of +10 o C. The layout of the heat carrier movement is cross-linked. Research results and their discussion. The temperature change for different ventilation systems. For tunnel ventilation, the temperature in the TA decreases from +40 to +22.5 o C (Fig. 2), and for the side - from +40 to +19,7 o С. Conclusions and perspectives. 1. A new design of a shell-tube heat exchanger with a compact arrangement of pipes in tubular beams is proposed and developed. 2. Computer-aided mathematical modeling of heat and mass transfer processes in bundles of pipes of different geometries with compact placement of pipes using the software ANSYS Fluent. The fields of velocities, temperatures, and pressure in the studied channels are obtained. The conditions of the hydrodynamic flow in the channels were analyzed and estimates of the heat transfer intensity between the hot and cold coolant through the wall separating them. 3. It was determined that the tunnel ventilation system would be most effective and TA was designed for it.

To the method of studying the permittivity of soils (on an example of soils of ravine forests of the northern variant of the steppe zone of Ukraine)

The article is devoted to the establishment of the peculiarities of the method for studying the dielectric permittivity of soils, which is its important electrophysical characteristic. The dielectric permittivity of the soil, which is a complex multiphase medium, depends on the dielectric properties of the mineral composition of its solid phase, the chemical composition, structure and composition of soil particles, their shape and size, and also the dielectric features of inter-porous air and moisture. Now it is possible to greatly simplify the technique of measuring the dielectric permittivity of soils due to the wide dissemination of compact digital instruments that provide high accuracy in measuring the capacitive characteristics of various media. For the approbation of the method, samples of soils of ravine forests of the northern variant of the steppe zone of Ukraine were used, as well as individual soil fractions of 2–3, 1–2 and 0.5–1 mm. All samples were studied in an air-dry state to level out the effect of moisture on the dielectric permittivity of soils, as described in many scientific papers. For measurements, a cylindrical condenser made of organic glass was manufactured, which does not conduct an electric current. The diameter of the capacitor plates was 20 mm, the distance between them was 0.7 mm. After placing the sample in the condenser, it was sealed by pressure from above the weight of about 0.3 kg to create a better contact with the covers of the capacitor. The measurements were carried out using a digital capacitance meter CM-9601A in the range of 0.1–200 picofarads at a test frequency of 800 Hz. At the end of the measurement, the soil sample was weighed to calculate its density. All measurements were performed three times. As a result of using this technique, it was found that the permittivity of a general soil sample is generally higher than that of individual soil fractions. This is explained by the more compact placement of soil particles in the soil sample and its greater density, while in studies of individual fractions, due to their shape, there remain pores between the aggregates that are not filled with soil material, which cause a decrease in sample density. As a result, the maximum density is typical for the soil fraction 0.5–1 mm, and the minimum for the fraction 2–3 mm. This is due to the fact that the maximum permittivity, as a rule, is characteristic for the fraction 0.5–1 mm, and the minimum for the fraction 2–3 mm. This assertion was proved by the measurements carried out. It was also found that the value of dielectric permittivity is significantly affected by soil enrichment of the clay fraction, the increased content of which causes an increase in the dielectric permittivity. Thus, as a result of the research, a method for measuring the dielectric permittivity of soils was tested using a modern digital capacitive meter. An increase in the dielectric permittivity of soils with an increase in their density and an increase in the content of the clay fraction was established. Soils, in general, have an increased permittivity in comparison with soil fractions of 2–3, 1–2 and 0.5–1 mm. There was a need to develop and approbate a technique for measuring the dielectric permittivity of soils in the field using undisturbed addition samples. In the future, in complex studies of soils, it is also desirable to perform a measurement of their dielectric permeability.

Dipole polarizability of nanodiamonds and related structures

In the present work, mean dipole polarizabilities of the nanodiamonds and the related nanostructures modified with nitrogen vacancy centers or surface functional groups F and OH have been studied by DFT methods. Linear correlation between the mean polarizability and the size of nanodiamonds has been justified. It opens opportunities for prediction of polarizabilities of larger nanodiamond particles without high-cost quantum-chemical calculations. Introducing nitrogen vacancy centers slightly increases the resulting mean polarizability due to the repulsive interactions of lone pairs of N atoms (in A, B, and N3 centers) or unpaired electron (C center). Mean polarizabilities of polyfluorinated and polyhydroxylated nanodiamonds have been calculated for model structures with isolated, focal, and compact arrangements of the F/OHs on the surface. The enhancement of polarizability over the expected additive value has been found for nanodiamonds with compact placement of F/OH and in the case of the polyhydroxylated nanodiamond with the isolated OH groups.

Optimization algorithm for PCB assembly of modular mounters

We propose an optimization method to maximize the productivity of PCB assembly of modular mounters. The modular mounter is a series of compact SMD placement modules each having assembly heads and feeder lanes. The throughput of the mounter is maximized by balancing the assembly time of each module. We identify the problem as an integer programming problem, and divide the problem into a feeder arrangement problem and a mount sequence problem by decoupling the path into forward arcs and backward arcs. Integer-programming based algorithms such as the branch-andbound algorithm and transportation algorithm are applied to solve the formulated problems. Simulation results are presented to verify the usefulness of the proposed method.

複合遊星ギアを用いたロボットフィンガの新機構

This paper presents a new mechanism for artificial fingers. It enables adduction/abduction of the MP joint in addition to the synergetic flexion/extension of the DIP, PIP and MP joints. The key mechanism is the newly invented double planetary gear system (DPGS) that allows three DOF motions of the finger in a compact placement of all actuators in a palm. The DPGS receives two input torques; one is an active torque coming from DC-motors, which drives solar gears, the other is a passive torque around the carrier of the planetary gears generated by a spring. This active/passive hybrid actuation enables to grip unknown shape objects with no sensory feedback. This paper describes the kinematics and the kinetics of the newly developed mechanism followed by the kinetics of pinching the object by two-fingers. It also shows the results of a couple of experiments. Additionally, we show a new mechanical design aiming for constructing a multi-fingered hand.

Floorplanning using a tree representation a summary

We present an ordered tree (O-tree) structure to represent nonslicing floorplans. The O-tree uses only n (2+[lg n]) bits for a floorplan of n rectangular blocks. We define an admissible placement as a compacted placement in both x and y directions. For each admissible placement, we can find an O-tree representation. We show that the number of possible O-tree combinations is O(n!2/sup 2n-2//n/sup 1.5/). This is very concise compared to a sequence pair representation that has O((n!) <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ) combinations. The approximate ratio of sequence pair and O-tree combinations is O(n <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> (n/4e)/sup n/). The complexity of an O-tree is even smaller than a binary tree structure for a slicing floorplan that has O(n!2/sup 5n-3//n/sup 1.5/) combinations. Given an O-tree, it takes only linear time to construct the placement and its constraint graph. We have developed a deterministic floorplanning algorithm utilizing the structure of O-tree. Empirical results on MCNC (www.mcnc.org) benchmarks show promising performance with average 16% improvement in wire length and 1% less dead space over the previous central processing unit (CPU) intensive cluster refinement method.

Floorplanning using a tree representation

We present an ordered tree (O tree) structure to represent nonslicing floorplans. The O tree uses only n(2+[lg n]) bits for a floorplan of n rectangular blocks. We define an admissible placement as a compacted placement in both x and y directions. For each admissible placement, we can find an O-tree representation. We show that the number of possible O-tree combinations is O(n!2/sup 2n-2//n/sup l.5/). This is very concise compared to a sequence pair representation that has O((n!)/sup 2/) combinations. The approximate ratio of sequence pair and O-tree combinations is O(n/sup 2/(n/4e)/sup n/). The complexity of O tree is even smaller than a binary tree structure for slicing floorplan that has O(n!2/sup 5n-3//n/sup 1.5/) combinations. Given an O tree, it takes only linear time to construct the placement and its constraint graph. We have developed a deterministic floorplanning algorithm utilizing the structure of O tree. Empirical results on MCNC (www.mcnc.org) benchmarks show promising performance with average 16% improvement in wire length and 1% less dead space over previous central processing unit (CPU) intensive cluster refinement method.