Vacant Cells Research Articles

Ising Paradigm in Isobaric Ensembles.

We review recent work on Ising-like models with "compressible cells" of fluctuating volume that, as such, are naturally treated in NpT and μpT ensembles. Besides volumetric phenomena, local entropic effects crucially underlie the models. We focus on "compressible cell gases" (CCG), namely, lattice gases with fluctuating cell volumes, and "compressible cell liquids" (CCL) with singly occupied cells and fluctuating cell volumes. CCGs contemplate singular diameters and "Yang-Yang features" predicted by the "complete scaling" formulation of asymmetric fluid criticality, with a specific version incorporating "ice-like" hydrogen bonding further describing the "singularity-free scenario" for the low-temperature unusual thermodynamics of supercooled water. In turn, suitable CCL variants constitute adequate prototypes of water-like liquid-liquid criticality and the freezing transition of a system of hard spheres. On incorporating vacant cells to such two-state CCL variants, one obtains three-state, BEG-like models providing a satisfactory description of water's "second-critical-point scenario" and the whole phase behavior of a simple substance like argon. Future challenges comprise water's crystal-fluid phase behavior and metastable states.

Unidirectional photonic reflector using a defective atomic lattice

Based on the broken spatial symmetry, we propose a scheme for engineering a unidirectional photonic reflector using a one-dimensional atomic lattice with defective cells that have been specifically designed to be vacant. By trapping three-level atoms and driving them into the regime of electromagnetically induced transparency, and through the skillful design of the number and position of vacant cells in the lattice, numerical simulations demonstrate that a broad and high unidirectional reflection region can be realized within the EIT window. This proposed unidirectional reflector scheme provides a new platform for achieving optical nonreciprocity and has potential applications for designing optical circuits and devices of nonreciprocity at extremely low energy levels. Published by the American Physical Society 2024

Dynamic manipulation of three-color light reflection in a defective atomic lattice.

We extend a recent theoretical work [Phys. Rev. A101, 053856 (2020)10.1103/PhysRevA.101.053856] by replacing disorders characterized by varied atomic densities with defects characterized by vacant lattice cells to evaluate again three-color reflection in a one-dimensional optical lattice filled with cold 87Rb atoms. This is based on the consideration that trapped atoms may escape from some lattice cells and effects of vacant cells on light propagation are of major importance from both fundamental and applied research viewpoints. We consider two types of defective atomic lattices where vacant cells are randomly or continuously distributed among filled cells. Numerical results show that the wider reflection band in a large detuning region of negligible off-resonance absorption is quite sensitive to, while the narrower reflection bands in two near-resonant regions of electromagnetically induced transparency are rather robust against, the number of random vacant cells. In contrast, all three reflection bands exhibit strong robustness against the number of continuous vacant cells. Note, however, that both narrower reflection bands may become widened and exhibit a blue shift when continuous vacant cells appear in the front of our atomic lattice due to the joint contributions of Bragg scattering and quantum interference.

Climate and land‐use change drive habitat loss in a mountain bird species

Mountain areas still feature remnants of traditional land use and consequently constitute a large proportion of the remaining species‐rich habitats in Central Europe. However, their biodiversity is increasingly threatened by changes in climate and land use. The Alpine Ring Ouzel Turdus torquatus alpestris is a typical mountain bird that has recently declined in most of its breeding range. In this study we compared the historical (1986–1987) and recent (2017) distribution of breeding Ring Ouzels in 62 randomly selected 750 × 750 ‐m plots and analysed local colonization and extinction patterns in 558 subunits (= ‘grid cells’) in the southern Black Forest (south‐western Germany). Our study revealed that habitat occupancy has decreased by about one‐third, mainly at lower elevations and in depressed landforms, during the past three decades. Local colonization amounted to 25% and extinction to 66% of the previously vacant or occupied grid cells, respectively. Habitat occupancy and local colonization and extinction were driven by climate and habitat parameters. The Ring Ouzel preferred convex landscape formations such as mountain peaks and ridges with long snow‐cover duration for breeding. Sites with high proportions of deciduous forest and abandoned pasture were avoided. Local colonization was higher at convex landscape formations and by high coniferous forest coverage and forest‐edge length. Local extinction, on the other hand, was lower at convex landscape formations and high‐elevation sites. Our results suggest that shorter persistence of snow fields caused by climate change and degradation of feeding grounds through land‐use abandonment might severely deteriorate food availability for the species, which is likely to have contributed to the observed decline. For conservation of the Alpine Ring Ouzel, we recommend adopting measures to mitigate the negative effects of climate warming and improve habitat quality. The creation of small‐scale mosaics of sparse conifer forests and regularly grazed pastures, especially on north‐ and east‐facing slopes on the lee sides of hills, mountain peaks or ridges, should be supported.

Effect of Inert Gas Vibrations in Bound States on the Equilibrium of a Vapor-Liquid System

The effect the vibrational motion of inert gas atoms in the bound states at an arbitrary density of a vapor–liquid system has on the equilibrium concentration dependence of the chemical potential on density is considered for the first time. Both the potential energy of interaction between atoms and their vibrations in the bound states, starting from an isolated dimer to a dense phase, are considered. Calculations are made using the lattice gas model (LGM) for a one-dimensional fluid. Spatial atomic distributions are described in a quasi-chemical approximation. Local frequencies of atoms are calculated in a quasi-dimer model of vibrational motion. At the same time, the translational motion of atoms when they move to neighboring vacant cells are considered. The calculations are made in two versions of the theory: discrete and continuum. The latter reflects the motion of the center of mass inside the cells into which the entire volume is partitioned in the LGM. It is found that allowing for the vibrations of atoms in the bound states at a fixed density of the system shifts the chemical potential to lower values.

Incorporating sprawl and adjacency measures in land‐use forecasting model: A case study of Collin County, TX

AbstractSprawl measures have largely been neglected in land‐use forecasting models. The current approach for land‐use allocation using optimization mostly utilizes objective functions and constraints that are non‐spatial in nature. Application of spatial constraints could take care of the contiguity and compactness of land uses and can be utilized to address urban sprawl. Because a land‐use model is used as an input to transportation modeling, a better spatial allocation strategy for more compact land‐use projections will promote better transportation planning and sustainable development. This study formulates a scenario‐based approach to normative modeling of urban sprawl. In doing so, it seeks to improve the land‐use projections by employing a spatial optimization model with contiguity and compactness consideration. This study incorporates urban sprawl measures based on smart growth principles together with a mixed‐use factor, and adjacency consideration of nearby land uses. The objective function used in the study maximizes net suitability based on imposed constraints. These constraints are based on smart growth principles that enhance walkability in neighborhoods, promote better health for residents, and encourage mixed‐use development. The formulated model has been applied to Collin County, TX, a fast‐developing suburban county located to the north of the Dallas–Fort Worth metroplex. The suitability of land cells indicates the probability of conversion, which is calculated using spatial discrete choice analysis with Moran eigenvector spatial filtering for vacant cells at a resolution of 150 × 150 m employing factors of the built environment, and socioeconomic and demographic characteristics. This study demonstrates how spatial proximity between land uses, which has been ignored to date, can be used to control sprawl, resulting in better mixing of different land uses based on constraints imposed in a spatial optimization problem.

Water's two-critical-point scenario in the Ising paradigm.

We present a spin-1, three-state Ising model for the unusual thermodynamics of fluid water. Thus, besides vacant cells, we consider singly occupied cells with two accessible volumes in such a way that the local structures of low density, energy, and entropy associated with water's low-temperature "icelike" order are characterized. The model has two order parameters that drive two phase transitions akin to the standard gas-liquid transition and water's hypothesized liquid-liquid transition. Its mean-field equation of state enables a satisfactory description of results from experiments and simulations for the ST2 and TIP4P/2005 force fields, from the phase diagram, the density maximum, or the deeply "stretched" states to the behavior of thermodynamic response functions at low temperatures at which water exists as a supercooled liquid. It is concluded that the model may be regarded as a most basic prototype of the so-called "two-critical-point scenario."

Exploring technology opportunities by visualizing patent information based on generative topographic mapping and link prediction

The shortening lifetime of technology requires companies to make intensive efforts to continuously explore new technology. Although many researchers have proposed visualization methods to find technology opportunities, little attention has been paid to present detailed directions of technology development with specified characteristics of technology. Thus, this research aims to suggest a systematic approach to conducting technology opportunity analysis by visualizing patent information, such as patent documents and citation relationships. First, keywords that explain core concepts, functions, and so on are extracted from collected patent documents by text mining. Second, patents are visualized in a two-dimensional space, and vacant cells are identified with their estimated keyword vectors by generative topographic mapping (GTM). Third, since many vacant cells will be potential candidates for developing new technologies, link prediction tools can choose promising vacant cells to connect existing cells with potential, but not yet existent, cells. Finally, the results of prediction are tested by comparing the predicted cells with the actual developed cells. The research reported in this paper is based in three technologies that have emerging, stable, and declining patterns, in order to illustrate the proposed approach, and investigate in which types it is relevant. It is found that the proposed approach provided a good prediction performance in the case of a technology that has a stable pattern. In addition, among link prediction methods, a semantic similarity-based approach showed better prediction results than a machine learning technique due to modest data availability for training. Thus, the results of this research can help R&D managers plan and evaluate R&D projects for technology development.

State Equation of a Nanocrystal with Vacancies

An expression for the Helmholtz free energy is established and the equation of state is derived for a nanocrystal containing vacancies in the lattice and delocalized (diffusing) atoms. The calculations are performed for bcc (body-centered cubic) iron under the isothermal compression of a nanocrystal along the 300-K and 1000-K isotherms. The changes in the specific surface energy (σ), the probability of vacancy formation (ϕ v ) and the probability of atom delocalization (x d ) are studied depending on the size (N) and shape of the nanocrystal at different temperatures (T) and pressures (P). The size dependences are characterized along two isobars: at atmospheric pressure (P = 1 bar) and at P = 100 kbar. As is shown, two P-points arise in the σ(P) isotherms at T ≤ 300 K, where the specific surface energy is independent of the nanocrystal size, which is σ(N) = σ(∞). As the temperature increases, the P points approach each other and at T ≥ 1000 K they vanish in the isotherms. At atmospheric pressure and T = 300 K the amount of vacancies per atom in a nanocrystal is much lower than that in a macrocrystal; however, at T = 1000 K the shredding of the latter leads to an increase in the probability of vacancy formation. Moreover, the smaller the nanocrystal size, the higher the probability of atom delocalization (as well as the self-diffusion coefficient) at any pressure and temperature. The ratio ϕ v /x d decreases with decreasing size of the nanocrystal, and less than a certain size, there is an no-vacansies self-diffusion, at which the number of delocalized atoms is greater than the amount of vacant cells in the nanocrystal lattice, i.e., ϕ v < x d . As the nanocrystal shape becomes different from the energetically optimal, the size dependences of the lattice properties of the nanocrystal are enhanced.

Effective bandstructures from unfolding supercells with vacancies

We study how vacancies alter the effective primitive cell bands projected out of supercell eigenstates via Brillouin zone unfolding. Two types of vacant primitive cells are of particular interest: Fully vacant, in which all atoms in a single cell are missing; and net fully vacant, in which the atoms comprising a full set for a single cell are missing from more than one cell. We find that a fully vacant primitive cell and a net fully vacant primitive cell have the same effect on the primitive cell bands. We show that the probability reduction for any primitive cell band is the same, regardless of band or wavevector in the primitive cell Brillouin zone, for both fully and net fully vacant primitive cells. We illustrate these results with a two-band model.

Path Optimization for Seedling Transplanting Based on TPCG Strategy

In facility agriculture, automated transplanter is used to transplant the healthy seedlings in vacant cells to replace the bad ones. It can make full use of space and nutrition. And the working efficiency could be improved by selecting a shorter transplanting path length. In this paper, a path optimization strategy based on tray position control and greedy algorithm (TPCG) was introduced. 260 samples with randomly location vacant holes tray were used to do transplanting path planning simulation. And TPCG was compared with fixed sequence (FS). The results showed TPCG could shorten over 18% of the path length for 32 cell trays, and more than 16% of path length for 128 cell trays. The transplanting efficiency was improved and the operation time was 0.302s which could meet the real-time requirement of transplanting task.

User Point Processes in Cellular Networks

The point process of concurrent users is critical for the analysis of cellular systems, in particular for the uplink and for full-duplex communication. We analyze the properties of two popular models. For the first one, we provide an accurate characterization of the pair correlation functions from the user and the base station point of view, which are applied to approximate the user process by Poisson and Ginibre point processes. For the second model, which includes the first model asymptotically, we study the cell vacancy probability, the mean area of vacant and occupied cells, the user-base station distance, and the pair correlation function in lightly and heavily loaded regimes.

Technology-Based New Service Idea Generation for Smart Spaces: Application of 5G Mobile Communication Technology

Innovative technology has made it possible to dramatically change the social and economic environment. In particular, 5G mobile communication technology that radically improves the performance of current technology can renew urban infrastructure, public services, and citizens’ lives for the implementation of smart spaces. Although new services need to be generated by such innovative technology, existing technology-based approaches have mostly relied on the intuition of experts rather than a systematic approach. Thus, this paper aims to present a method and process by which technology-based new ideas using 5G mobile communication technology are generated to realize a connected environment by focusing on technological functions as well as customer value. First, the relationships among technology, value, and service are defined through morphology analysis. Second, service opportunities are identified by developing a transformed buyer-utility map in the smart space environment. After mapping the established services, candidate cells for a new service were identified as vacant cells in the map with the removal of technically unnecessary candidates based upon the pre-defined relationship. Third, a new service idea is generated by modifying/extending candidates concretely through an ERRC (Eliminate, Reduce, Raise, Create) framework. Value factors are determined in advance and shown in the As-Is value curve representing the current status. The current level in the curve is then compared at an industrial level and value factors are chosen to newly modify or create. As a result, the To-Be curve is established and leads to a new service idea. It can be regarded as a useful tool for mobile carriers to plan new business models for smart spaces with adequate technology and market feasibility.

Role of S100A4 in the epithelial-mesenchymal transition of esophageal squamous cell carcinoma and its molecular mechanism

To explore the role of S100A4 in the epithelial-mesenchymal transition (EMT) in esophageal squamous cell carcinoma and its possible molecular mechanism. Three chemically synthesized S100A4 siRNA sequences were transiently transfected into esophageal carcinoma EC9706 cells. EC9706 cells transfected with negative siRNA, lipofectamine 2000, and vacant EC9706 cells were used as control. Fluorescence quantitative RT-PCR and Western blot were used to detect the inhibition rate of S100A4 siRNA. S100A4 siRNA2 with the best inhibition rate was chosen to transiently transfect into EC9706 cells under the same conditions. The EC9706 cells transfected with negative siRNA, lipofectamine 2000 and vacant EC9706 cells were also used as control. Fluorescence quantitative RT-PCR and Western blot were used to detect the mRNA and protein expressions of E-cadherin, vimentin and snail. The morphology of EC9706 cells was observed under an inverted microscope. Boyden chamber and scratch test were used to detect the invasion and migration ability of EC9706 cells, and CCK8 assay was used to detect the proliferation ability of EC9706 cells. EC9706 cells transfected with S100A4 siRNA2 were further transfected with snail eukaryotic expression vector. The EC9706 cells transfected with S100A4 siRNA, EC9706 cells transfected with snail eukaryotic expression vector and vacant EC9706 cells were used as control. The above indexes of all the groups were observed, too. The S100A4 mRNA and protein expression levels of the S100A4 siRNA2 group were 0.417 ± 0.041 and 0.337 ± 0.039, the transmembrane cell number was 61.608 ± 8.937, the scratch healing distance was (0.216 ± 0.064) mm, the A value was 0.623 ± 0.084, the E-cadherin mRNA and protein levels were 0.619 ± 0.032 and 0.495 ± 0.034, the vimentin mRNA and protein levels were 0.514 ± 0.032 and 0.427 ± 0.028, the snail mRNA and protein levels were 0.573 ± 0.029 and 0.429 ± 0.041. These data were significantly different with the liposome group, the negative control group and the blank group (P < 0.05 for all). After the S100A4 siRNA2 treatment for 24 h, the appearance of EC9706 cells changed to epithelial cell morphology. The transmembrane cell number and the scratch healing distance of the S100A4 siRNA2+snail eukaryotic expression vector group were (69.382 ± 9.666) cells and (0.274 ± 0.029) mm, the A value was 0.823 ± 0.101, the snail mRNA and protein levels were 0.704 ± 0.037 and 0.625 ± 0.031, the vimentin mRNA and protein levels were 0.712 ± 0.046 and 0.609 ± 0.038, and these data were significantly higher than those of the Sl00A4 siRNA2 group (P < 0.05 for all). The E-cadherin mRNA and protein levels of the S100A4 siRNA2+eukaryotic expression vector group were 0.437 ± 0.038 and 0.381 ± 0.031, significantly lower than those of the S100A4 siRNA2 group (P < 0.05 for all). However, snail had no effect on the morphology of EC9706 cells. S100A4 may be involved in the EMT process of esophageal squamous-cell carcinoma by regulating the expression of snail and then plays a role in the invasion and metastasis of esophageal carcinoma.

Effect of WW domail-containing oxidoreductase gene on apoptosis of papillary thyroid carcinoma cells and its mechanism

Objective To investigate the effects of WW domail-containing oxidoreductase (WWOX)-mediated apoptosis on papillary thyroid carcinoma in vitro and its possible mechanism. Methods A eukaryotic expression vector containing WWOX was transfected into papillary thyroid cancer cell line K1(recombinant plasmid group),and positive cell clones were selected and amplified. Synthesized small interfering RNA(siRNA) targeting WWOX(WWOX siRNA group) was transfected into TPC-1 cells.On the other hand, TPC-1 cells transfected with Lipofectamine 2000(liposomes control group)and vacant TPC-1 cells(blank control group) were used as controls.The expression of WWOX m RNA was detected by real-time quantitative reverse transcriptase-polymerase chain reaction(RT-qPCR).The effects of WWOX on apoptosis releated protein were analyzed by Western blotting. Results Recombinant plasmid group cells could steadily express WWOX mRNA, which was more than 4. 5 times higher than plasmid group and blank control group(P< 0. 05).The absorbance of TPC-1 cells decreased greatly after transfection with WWOX siRNA, which was 0. 2 times lower than in control groups(P< 0. 05).Forced expression of WWOX in K1 cells enhanced the expression of apoptosis releated protein. Conversely, knockdown of WWOX in TPC-1 cells using siRNA targeting WWOX decreased the expression of apoptosis releated protein. Conclusion WWOX can promote apoptosis of human PTC cells through a mechanism which may be assocoated with activation of the mitochondrial apoptosis pathway. Key words: WW domail-containing; Oxidoreductase gene; Apoptosis; Gene transfection

Properties of an almost localized Fermi liquid in an applied magnetic field revisited: a statistically consistent Gutzwiller approach

We discuss the Hubbard model in an applied magnetic field and analyze the properties of neutral spin- fermions within the so-called statistically consistent Gutzwiller approximation. The magnetization curve reproduces in a semiquantitative manner the experimental data for liquid 3He in the regime of moderate correlations and in the presence of a small number of vacant cells, modeled by a non-half-filled band situation, when a small number of vacancies (∼5%) is introduced in the virtual fcc lattice. We also present the results for the magnetic susceptibility and the specific heat, in which a metamagnetic-like behavior is also singled out in a non-half-filled band case.

Effects of Tetranychus lintearius (Acari: Tetranychidae) on the structure and water potential in the foliage of the invasive Ulex europaeus (Fabaceae) in Australia

Ulex europaeus, a native of Western Europe and the Mediterranean coast, is a serious agricultural and environmental weed in many parts of the earth, including Australia. Tetranychus lintearius attacks U. europaeus in its natural range and is one of the four biological control agents introduced into Australia to regulate populations of U. europaeus. Tetranychus lintearius is specific to different species of Ulex, which enhances its status as a key biological control agent. Little is known on the physiological effects and structural changes induced by T. lintearius on U. europaeus. This article describes anatomical changes and evaluates the physiological effects in U. europaeus consequent to feeding by T. lintearius for more than 100 d. This study demonstrates that feeding by T. lintearius reduces the quantity of photosynthetic tissue in U. europaeus, as a result of feeding on mesophyll parenchyma by inserting its stylets through the stomatal aperture. Unfed parenchyma cells display signs of stress, either exhibiting deformed cell organelles aligned along the walls of vacant cells or with cells with no well-defined cell organelles. Subsequent to T. lintearius feeding, leaves externally manifest bleaching. After feeding by a population of T. lintearius, leaf water potential is decreased by 30% and tender shoots lose their turgor, indicating water-related stress. Tetranychus lintearius has the potential to decelerate vigour and retard the competitiveness of U. europaeus by inflicting stress. Our findings reinforce the use of T. lintearius in the biological management of populations of U. europaeus in temperate Australia.

Effects of local density of clonal plants on their sexual and vegetative propagation strategies in a lattice structure model

Clonal plants can propagate both sexually and vegetatively and the balance between the efforts of sexual and vegetative propagation can be determined by inter- and intra-specific competition. This raises the question of whether sexual propagation becomes more suitable than vegetative propagation or vice versa. Some studies suggest seed production is positively correlated with plant density, and others, negatively. To evaluate the effects of local density of ramets on plant propagation strategy, we developed a lattice model where two strategies compete with each other. In the model, a plant changes its strategy based on local density as defined by the proportion of neighboring lattice cells containing plants. One strategy produces seeds at high local density (SEEDING at HLD) and produces ramets at low local density, and the other strategy produces ramets at high local density (RAMETING at HLD) and seeds at low local density. Seeds can spread all cells while ramets can reach only adjacent cells, and if an individual from a seed competes with an individual from a vegetative propagule, the latter always wins. Each plant has different thresholds to change its strategy from sexual to vegetative, or vice versa, along with local density. In the model, a realized density depends on both reproductive rate and mortality; thus, we evaluate the performance of each strategy under different mortalities.When mortality is high, a realized density becomes low. Under this condition, plants reproduce mainly by seeds (either the SEEDING at HLD plants with lower threshold values, or RAMETING at HLD plants with higher threshold values) and show high performance. High mortality results in many vacant lattice cells that do not have neighboring plants. Since vegetative propagules cannot reach these isolated vacant lattice cells while seeds can, plants that propagate mostly or exclusively by seed become dominant. When mortality is low, the local density becomes high and few cells are available for new individuals. Under this condition, SEEDING at HLD becomes dominant. SEEDING at HLD plants with a high threshold value almost always reproduce ramets, but they also produce seeds when neighboring cells are completely occupied. Although SEEDING at HLD plants with a high threshold value and RAMETING at HLD plants have an equal chance to get established by vegetative propagation, SEEDING at HLD plants also produce seeds when there are no vacant neighboring cells (i.e., high density), and those seeds can, although rarely, establish new individuals. In conclusion, the production of ramets at lower densities and the production of seeds at higher densities seem to be a proper strategy in our model.

Thermal energy conduction in a honey bee comb due to cell-heating bees

Theoretical analysis and numerical calculations are performed to characterize the unsteady two-dimensional conduction of thermal energy in an idealized honey bee comb. The situation explored corresponds to a comb containing a number of brood cells occupied by pupae. These cells are surrounded by other cells containing pollen which, in turn, are surrounded (above) by cells containing honey and (below) by vacant cells containing air. Up to five vacant cells in the brood region can be occupied by cell-heating bees which, through the isometrical contraction of their flight muscles, can generate sufficient energy to raise their body temperatures by a few degrees. In this way, the cell-heating bees alter the heat flux and temperature distributions in the brood region so as to maintain conditions that benefit the pupae. The calculations show that the number of cell-heating bees significantly affects the magnitude, time rate of change, and spatial distribution of temperature throughout the comb. They also reveal a vertically aligned asymmetry in the spatial distribution of temperature that is due to the large heat capacity and thermal conductivity of honey relative to air, whereby air-filled cells experience larger temperature increases than honey-filled cells. Analysis shows that convection and radiation represent negligible modes of thermal energy transfer at all levels in the problem considered. Also, because of its small thickness, the wax wall of a comb cell simultaneously presents negligible resistance to conduction heat transfer normal to it and very large resistance along it. As a consequence the walls of a cell play no thermal role, but simply serve as mechanical supports for the materials they contain.

主に空地を介した土地利用移転によって形成される土地利用パターンの特徴 : マルチエージェントの満足度戦略による土地移転モデルその3

The characteristics of land use formation made by the replacement of land according to the degree of affinity between land uses: residence, commerce, industry, green, vacant and suburbs, are analyzed. The land use formation is formed by the simulation using cellular automata. 1. Method of Simulation (1) The cells of residence, commerce, industry and green are not exchanged directly, but exchanged through vacant or suburbs. (2) The cells of residence, commerce, industry and green take an egoism strategy to land use exchange. (3) The vacant cell takes an altruism strategy or an egoism strategy to land use exchange. 2. Result (1) In the case of a vacant cell taking an altruism strategy: Vacant cells exist between the land use settlements, and form a city outline. A city outline is simple and clear. (2) In the case of a vacant cell taking an egoism strategy: Vacant cells exist inside of the land use settlement. A city outline is complicated and is not clear.