Buildings In Zones Research Articles

Vertical and horizontal displacements of a reservoir slope due to slope aging effect, rainfall, and reservoir water

Landslides are common hazards in reservoir areas and significantly affect dam operation and human lives. For the prevention and management of landslides, accurate assessment of the factors influencing their generation is essential. This study evaluated the key external factors influencing horizontal and vertical displacements of Luobogang Reservoir Slope in Hanyuan County, China. Displacements had been monitored by a surface-displacement-monitoring system consisting of 118 GPS stations during 2012–2015. To identify the external driving factors, their influence zones, and slope responses, we analyzed 32 months of displacement measurements and other multi-source datasets using the empirical orthogonal function. Overall, the results show that slope aging effect, rainfall, and reservoir water levels are three main driving factors. For horizontal displacement, aging effect is the most critical factor and predominantly affects the edges of landslides, the gob cave, and the public building zones. The secondary factor is the reservoir water level, which mainly acts on the boundary between the slope and reservoir water surface. The closer the slope zone is to the reservoir water, the more significant the impact is. Regarding vertical displacement, the most important factor is rainfall. The vertical displacement caused by rainfall accounts for 56.76% of the total vertical displacements. However, rainfall induces elastic displacements that generally cause less damage to the slope. The secondary factor is aging effect, and the vertical displacement caused by aging effect accounts for 9.42%. However, seven individual zones are highly affected by slope aging effect, which is consistent with the distribution of public buildings.

Neoliberalism of disaster and long-term recovery: The case of the 2010 earthquake in Talcahuano, Chile

In this article, it was analyzed the long-term disaster recovery after the earthquake and tsunami that affected Talcahuano, Chile in February 2010. Under the assumption that disaster governance is neither politically nor discursively neuter, the aim of this article is to describe the long-term recovery process of Talcahuano, where urban planning was adjusted to the political neoliberal frame. We used a unique-case study. There were considered 7 maps that show longitudinally the changes in Talcahuano's city design. There are maps about tsunami risk zones and landslide risk zones. Additionally, there were used 25 interviews to complement the recovery process. The results show that Talcahuano experienced post disaster changes in urban planning in line with neoliberal politics. The changes can be seen in the enlargement of commercial and residential zones. In some cases, the new building zones overlap in potentially risky zones of coastline and hills. The conclusions of the study show there is a recovery in terms of rebuilding and the organization of its local governance in emergency responses. Nevertheless, it was not able to avoid the general frame given by neoliberal regime. For more than a decade, the post-disaster recovery process favors the market growth and partially omit the local community participation in decision-making about the city design. The study case about 2010 earthquake in Talcahuano, Chile, contributes to observe long-term recovery as complex processes where the political regime aspects should be included in the analysis.

Integration of Laser Scanner and Photogrammetry for Heritage BIM Enhancement

Digital 3D capture and reliable reproduction of architectural features is the first and most difficult step towards defining a heritage BIM. Three-dimensional digital survey technologies, such as TLS and photogrammetry, enable experts to scan buildings with a new level of detail. Challenges in the tracing of parametric objects in a TLS point cloud include the reconstruction of occluded parts, measurement of uncertainties relevant to surface reflectivity, and edge detection and location. In addition to image-based techniques being considered cost effective, highly flexible, and efficient in producing a high-quality 3D textured model, they also provide a better interpretation of surface linear characteristics. This article addresses an architecture survey workflow using photogrammetry and TLS to optimize a point cloud that is sufficient for a reliable HBIM. Fusion-based workflows were proposed during the recording of two heritage sites—the Matbouli House Museum in Historic Jeddah, a UNESCO World Heritage Site; and Asfan Castle. In the Matbouli House Museum building, which is rich with complex architectural features, multi-sensor recording was implemented at different resolutions and levels of detail. The TLS data were used to reconstruct the basic shape of the main structural elements, while the imagery’s superior radiometric data and accessibility were effectively used to enhance the TLS point clouds for improving the geometry, data interpretation, and parametric tracing of irregular objects in the facade. Furthermore, in the workflow that is considered to be the ragged terrain of the Castle of Asfan, here, the TLS point cloud was supplemented with UAV data in the upper building zones where the shadow data originated. Both datasets were registered using an ICP algorithm to scale the photogrammetric data and define their actual position in the construction system. The hybrid scans were imported and processed in the BIM environment. The building components were segmented and classified into regular and irregular surfaces, in order to perform detailed building information modeling of the architectural elements. The proposed workflows demonstrated an appropriate performance in terms of reliable and complete BIM mapping in the complex structures.

A tool for generation of stochastic occupant-based internal loads using a functional data analysis approach to re-define ‘activity’

In building energy simulation (BES), internal loads are typically defined as hourly schedules based on occupant-related ‘activities’ assigned to each building zone. In this paper, a data-centric bottom-up functional data analysis model is used to examine how activities in a building correlate with energy demand for plug loads and lighting. Functional principal component analysis and hierarchical clustering of the principal component scores have been used to explore the links between the data and zone activity. The results show that plug loads show limited links to activity to the extent that the activity determines the variability of the data. The lighting loads show little correlation with zone activity but instead are determined primarily by the building control system. A novel methodology is proposed for the generation of stochastic load data for input into BES. This methodology has been developed into a tool for stochastic load generation which is available online.

Sequence-to-sequence deep learning model for building energy consumption prediction with dynamic simulation modeling

This study used a more detailed dataset approach to address the limitations of existing building energy prediction methods and to predict building energy demand more accurately. The EnergyPlus dynamic simulation program closely modeled building envelope performance, zone division, and heating, ventilation, and air conditioning systems. Building energy simulation used actual weather data and generated occupancy data. The occupancy, lighting, and equipment schedules for each zone were generated in 5-min intervals using the Lawrence Berkeley National Laboratory occupancy simulator. Summer electric power consumption based on Internet of Things information from the testbed building validated the model. When applying generated occupancy, lighting, and equipment schedules, the mean bias error of simulation similarly improved to 4.73%, and the coefficient of variation of the root-mean-squared error (Cv(RMSE]) improved to 12.26%. Subsequently, a demand prediction model was constructed as a sequence-to-sequence (seq2seq) model using long short-term memory (LSTM) cells in recurrent neural network (RNN) algorithms, then its accuracy was evaluated. In the seq2seq model, the learning performance based on the EnergyPlus data exhibited an RMSE of 4.48% and a weighted average percentage error of 3.07%. As a result of applying prediction methods while changing climate scenarios, prediction performance also satisfied statistically significant levels. The occupancy information and solar radiation were determined to exert the greatest influence on the building energy demand prediction. • The occupant schedule for each zone was generated in 5-min intervals using the LBNL occupancy simulator. • When applying the generated internal schedules, the MBE improved to 4.73%, and the Cv(RMSE) improved to 12.26%. • In the seq2seq model, the learning performance based on the EnergyPlus data exhibited an RMSE of 4.48% and a WAPE of 3.07%. • The occupant information and solar radiation were determined to exert the greatest influence on energy demand prediction.

Hierarchical flexibility potentials of residential buildings with responsive heat pumps: A case study of Denmark

In Denmark, the penetration of Renewable Energy Sources (RES) has increased from 44% in 2015 to 55% in 2020 and is scheduled to increase up to 100% by 2050. To overcome the intermittency and volatility of the RES, demand-side flexibility is an alternative solution for the Danish Electricity Market (DEM). In the residential sector, the heat pump is a practical solution to hedge against the supply-side uncertainties associated with RES. To fulfill the aim, this paper suggests a novel hierarchical structure for residential heat pumps to provide power system flexibility. An Economic Model Predictive Control (EMPC) is proposed to unlock the heat flexibility of residential buildings in response to RES availability. The three-stage stochastic programming is addressed to schedule, adjust, and regulate the heat flexibilities of buildings hierarchically in three trading floors of short-term electricity markets, including day-ahead, intraday, and balancing market floors, on long, mid, and short advance notices, respectively. Leveraging heat flexibility based on occupancy patterns, the thermal dynamics of buildings are developed to address different temperature zones in residential buildings. Finally, a Danish Test House with 4 temperature zones is simulated to show the applicability and proficiency of the suggested approach. The results confirm that the proposed approach not only provides flexibility to the DEM but also reduces the energy consumption cost of households.

Numerical study on thermal stratification for impinging jet ventilation system in office buildings

Thermal stratification is the key to improving energy efficiency and indoor air quality for impinging jet ventilation (IJV) system in cooling mode. However, unclear thermal stratification characteristics of IJV system can degrade the ventilation performance of the IJV. In the present study, the thermal stratification characteristics of an IJV is investigated by the validated simulation model for different supply air parameters and internal heat sources in interior zone of office buildings. The critical value of supply air parameters for the formation of thermal stratification is determined by thermal length scale, which considers the combined effect of inertial force and thermal buoyancy on the supply airflow. In addition, the cooling load in an IJV cooling room caused by the heat source intensity can be calculated directly and the heat source distribution is negligible. The results also indicate that the thermal stratification height (H) only depends on supply air parameters, while the temperature difference between head and ankle level (ΔT) is affected by both supply air parameters and cooling load. The predictive models of H and ΔT are obtained based on the simulation results, which could provide the theoretical basis for optimizing the design scheme of IJV system in interior zone of office buildings.

Impacts of high-rise building on urban airflows and pollutant dispersion under different temperature stratifications: Numerical investigations

In this study, the effects of high-rise building on the flow and pollutant dispersion under different temperature stratification conditions were simulated using the Reynolds Averaged Navier Stokes (RANS) method and standard k-ε turbulence model. The results showed the following: Both the height of central building and temperature stratification significantly affect the airflow around building arrays. When the height of the central building is 0H (H is the height of surrounding buildings), the flow structure under the different temperature stratification conditions are invariably wake interference flows in morphology but are markedly different in terms of the vortex morphology and quantity. When the height of the central building is 2H, the central building has marked blocking effect, increasing the complexity of the flow fields in the surrounding blocks, the length of the recirculation zones of downstream buildings, and the range of pollutant dispersion, particularly under stable conditions. Increasing the central building height to 2H markedly decreases the turbulent kinetic energy in downstream street canyons due to the effect of the recirculation zones of the central building. Under non-neutral conditions, increasing the central building height to 2H intensifies the mechanical turbulence, resulting in nonsignificant temperature stratification variations in the building arrays.

ТЯЖЕЛЫЕ МЕТАЛЛЫ В ГОРОДСКИХ ПОЧВАХ: ОЦЕНКА СОДЕРЖАНИЯ И ЭКОЛОГИЧЕСКОГО РИСКА

Актуальность исследования обусловлена необходимостью выявления особенностей накопления тяжелых металлов в почвах урболандшафтов Владивостока и Уссурийска и установления величины потенциального экологического риска. Целью работы является оценка геохимического состояния почв различных функциональных зон урболандшафтов с использованием нескольких индексов загрязнения. Методы. Валовое содержание элементов в почвах определяли методом рентгенфлуоресцентного анализа на спектрометре EDX-800HS (Shimadzu). Результаты. Под влиянием сильной техногенной нагрузки в верхних горизонтах почв урболандшафтов в наибольшей степени накапливаются хром, медь, цинк и свинец. Содержание ванадия, кобальта и никеля сравнимо с кларком или ниже его. Средние и максимальные значения комплексных коэффициентов загрязнения PLI и NPI свидетельствуют о деградации поверхностного слоя городских почв и сильной степени загрязнения тяжелыми металлами. Потенциальный экологический риск колеблется от незначительного до среднего. Степень загрязнения почв различных функциональных зон увеличивается в следующем ряду: рекреационная<многоэтажной застройки<транспортно-селитебная<малоэтажной застройки, уровень загрязнения варьирует от оценки «чиста почва» до оценки «сильно загрязненная почва». В некоторых почвах рекреационной зоны выявлена слабая аккумуляция хрома, цинка и меди. В почвах зоны многоэтажной застройки во Владивостоке обнаружено накопление хрома, меди, свинца и цинка (от слабого до среднего), а в Уссурийске отмечено только накопление меди. В почвах транспортно-селитебной зоны и зоны малоэтажной застройки с разной степенью интенсивности аккумулируются хром, медь, свинец и цинк. Более высокие значения как индивидуальных (Igeo, EF, PI), так и комплексных показателей загрязнения (NPI, PLI, PERI) выявлены в почвах Владивосток.

Research and Application of Predictive Control Method Based on Deep Reinforcement Learning for HVAC Systems

Energy efficiency and consumption control remain a significant topic in the area of Heating, Ventilation, and Air Conditioning (HVAC) systems. Deep reinforcement learning (DRL) is an emerging technique to optimize energy consumption. Its advantage lies in the ability to tackle the time-series nature of energy data and complexity brought by environmental factors. However, most DRL algorithms have not considered both time-of-use electricity pricing and thermal comfort. This paper proposed a hybrid approach based on twin delayed deep deterministic policy gradient algorithm and model predictive control (TD3-MPC) for HVAC systems, to mitigate function approximation errors and save cost by pre-adjusting building temperatures at off-peak times. This proposed method is compared with deep deterministic policy gradient (DDPG) algorithm under simulations of five building zones. Experiment results demonstrate that TD3-MPC outperforms DDPG algorithm and potentially saves 16% of total energy consumption cost, with better stability and robustness.

Air Exchange Rate and Internal Air Flows in a Naturally Ventilated Museum Building

A controlled indoor environment is crucial to the preservation of valuable historical artefacts in museums, but is influenced by many factors such as building properties, exhibit design, number of visitors, outdoor conditions etc. This study aims to monitor the local air exchange rates (AERs) and internal air flows in the Viking Ship Museum, Oslo, Norway during different outdoor conditions and is part of a project to create a new museum for the ships. Homogeneous emission tracer techniques (with tracer A) were used to monitor the local mean age of air (from which the local AER can be estimated). The internal air flows from a building zone were monitored by loading that zone with another tracer (B). The building outline is in the shape of a cross with four wings emanating from a central tower and thus naturally creates five zones to investigate. Three measurement periods were conducted with outdoor conditions ranging from winter to late summer. During winter conditions the average hourly air exchange rate (ACH) for the museum is fairly low (0.05 h-1), but during summer conditions it rises fourfold (0.2 h-1). During the summer, windows and doors may be kept open and the number of visitors peaks. The internal flows are very large, as indicated by very similar patterns of the sampler loads for both A and B tracers in relation to the twenty sampling positions.

ОЦЕНКА ПЫЛЕВОГО ЗАГРЯЗНЕНИЯ АТМОСФЕРЫ НАЗЕМНЫМИ И ДИСТАНЦИОННЫМИ МЕТОДАМИ (НА ПРИМЕРЕ Г. ТОБОЛЬСК)

Snow cover is an effective accumulator of dust fallout and provides objective information on the level of pollution, but its sampling in large areas takes a long time. The use of remote sensing data (RSD) makes it possible to significantly simplify the assessment of the dust load in the atmosphere. Based on RSD from the town of Tobolsk, we evaluated the information value of various indices used to assess the distribution and properties of snow cover (NDSI, normalized S3 index, and SCI). Data on dust load and physicochemical properties of the snow obtained during sampling and subsequent analysis were compared with the spectral properties of the snow cover. It was determined that the dust load in the town averaged 32,1 mg/m2 per day, which is approximately 8 times higher than the background values. The degree of alkalinization is moderate, an increase in pH and salinity of snowmelt waters is observed. In comparison with other functional zones of the town, no increase in dust fallout was detected in the industrial zone (Tobolsk Petrochemical Plant). The level of dustiness is maximum in the zone of multistory buildings and on the streets with the highest traffic intensity. It was established that spectral indices indicate the amount of solid impurities in snow and the level of alkalinization. A statistically significant correlation was found between the amount of insoluble particles in snow and the S3 index as well as between pH and the SCI index. The paper concludes that these indices can be used to assess the environmental situation in urbanized areas.

Prediction and Evaluation of Emergency Broadcasting Sound and Speech Intelligibility for Safety Zones in High-rise Buildings

As construction of high-rise buildings is increasing, the installation of a fire safety zone for the safe evacuation of residents has become mandatory. Even for building complexes with an underground connection between 30 and 49 stories, a fire safety zone must be installed when the residential density exceeds 1.5 people per square meter. In the fire safety zone, an automatic fire detection system and a system to assist radio communication must be installed. In addition, an emergency broadcasting system must be installed to announce the fire situation and to guide the safe evacuation of the residents. The fire safety zone was constructed with non-combustible material to minimize flames or smoke and was furnished to maintain a very low fire load. However, non-combustible materials have very low sound absorption characteristics; therefore, they usually reflect the sound energy into the spaces. In spaces consisting of sound reflective materials, the emergency broadcasting sounds reverberated, making it difficult to understand the meaning of the broadcasted sound. In this study, the room acoustics characteristics for fire safety zones in a high-rise building, represented as reverberation time and speech transmission index, were predicted using a certified room acoustics simulation method and evaluation of speech intelligibility. As a result of predicting the acoustic characteristics of the safety zone, it was found that the space had quite long reverberation and speech intelligibility was low, making it difficult to clearly transmit the emergency broadcast sound. When a safety zone was set up in a part of the machinery room, it was confirmed that it was difficult to clearly transmit the emergency broadcast sound, even when the background noise level was louder than 70 dB(A). To deliver a clear emergency broadcast sound in the safety zone, it is necessary to use inorganic sound-absorbing materials and to properly block noise in the machine room. In addition, it is necessary to establish guidelines for regulation of the speech transmission index for emergency broadcasting systems.

Group of tetradrachmas from the reign of Diocletian discovered at Kom el-Dikka in Alexandria

A set of more than 30 tetradrachmas from the second half of the 3rd century AD was discovered in Alexandria in Egypt, at the Kom el-Dikka site excavated by a Polish mission, in a zone of public buildings constructed in the 4th century AD. A row of lime kilns from the construction site of this complex stood on top of the ruins of an early Roman domestic quarter and, after they ceased to be used, were covered with earth and rubble, the latter partly from the destruction layer of these houses. Excavation of the kilns in 2008 and 2009 produced large quantities of 4th and 5th century pottery as well as pieces of marble revetment that had been fed to the kilns, and isolated late Roman coins. The tetradrachmas from two of the kilns (Fc and Fd), which were hoarded apparently in AD 293–295, seems to have preceded the destruction of the early Roman houses and may have been hidden in one of them.

Information Security Compliance Framework for Data Center in Utility Company

The utility organization has already implemented some of security framework and compliance in their data center to secure the data centers of valuable information. However, the implementation of security framework and compliance, still has several issues relates to some restricted areas. There is no effective security framework and compliance, being implemented in their data center such as access control management system at the entrance of the building zone. Therefore, the objective of this research is to develop information security compliance framework in data center in utility company. This research applied qualitative method namely semi structured interviews for data collection. The contribution of this research will help professionals and security management organizations to understand the best ways they can be used to improve physical security within the context of information security compliance frameworks that play an important role.

Spatial Analysis of the Zolotarevka Fortified Settlement Structures

The article examines the structures of the Zolotarevka fortified settlement (a medieval fortress in the upper reaches of the Sura River, Penza region), both from the points of view of building technologies and of spatial analysis. The zones of residential buildings and zones of economic and industrial structures were identified. The buildings themselves were located chaotically along the territory of the fortified settlement but were tied to internal roads. The average size of residential buildings was 4×3 m, and the economic – 2×2 m. Usually the pockets for cooking were located next to the side and fenced with wattle. Among the features two long structures (barracks) with a rammed platform between them may be singled out. The study of these materials also made it possible to identify the traditions of Ancient Russia and Volga Bulgaria. Particular attention is paid by the authors to the defensive structures that were formed over the years from 10th to 13th centuries and retain a number of unique elements. First of all, these were trapping pits located in a checkerboard pattern on the floor side of the settlement as well as coating the ditch with clay and internal paths along the rampart. To summarize, these facts make the Zolotarevka fortified settlement a reference monument of the medieval history of Eastern Europe.

THE INVESTIGATION OF DISTRIBUTION OF THE MAGNETIC FLUX DENSITY OF OPERATING TWO-CIRCUIT POWER LINE 110 KV «CHTPP-CHERNIHIV-330» IN THE RESIDENTIAL AREA AND METHODS OF ITS DECREASING TO A SAFE LEVEL

Purpose. The problem of evaluation and analysis of magnetic flux density of overhead power lines is very relevant now, since the magnetic field of industrial frequency can have a negative effect on human health. The analysis of the magnetic field of the operating double-circuit overhead transmission line was made in this work. This overhead line is in the residential area of Chernihiv, Ukraine. The purpose of this work is to determine safe habitation conditions as a function of the magnetic flux density along the route of two-circuit power line with the voltage 110 kV «ChTPP-Chernihiv-330». Real modes of operation are taken into account. Recommendations are given for reducing the magnetic flux density level in the residential area to a value that will not exceed the standard value. Methodology. Methods of electromagnetic field theory were used to calculate the magnetic field of power lines. The location of the phase wires on different types of supports of the existing power transmission line and the minimum distance between the conductors and the ground were taken into account. The current value of the current in the phases of the transmission line was taken from the Company «Chernihivoblenergo». Also, the calculation of the magnetic flux density was made for the perspective loads of the transmission line. Estimation of the value of the magnetic flux density was made for the zone of one-story and multi-story buildings near power lines. The option of uniform loading of two power transmission lines was considered and the case where the entire load is transferred along one circuit was also considered. Results. In this work, the distribution of magnetic flux density at a height of 1.8 m in the direction perpendicular to the power transmission line for the sections built on supports of the U110-2 and PB110-2 types was obtained. The graphs show that the magnitude of the magnetic flux density at the boundary of the protection zone of the transmission line will be exceed twice the standard value 0.5 μT for the existing and perspective loads. This problem is relevant in the case of transmission lines in single-circuit mode. The graphs of distribution of magnetic flux density on the facade of an apartment building, located at a distance of 20 m from the axis of symmetry of the transmission line, were constructed. As a result, it is shown that at a height of 11 m from the earth's surface, magnetic flux density will be 1.5-2 μT. Practical value. It is determined that safe habitation along the route of two-circuit power line with the voltage 110 kV «ChTPP-Chernihiv-330» can be achieved when facades of an apartment building are removed from the axis of symmetry of the transmission line at a distance of 33 m for high-rise buildings and at a distance of 27 m for one-storey buildings. Recommendations for reducing the magnetic flux density of this power transmission line have been developed.

Buffer zones of the loessial massifs ecological framework as the necessary condition of its sustainable development

The design of buffer zones of buildings consisting of ecological skeleton biogeocenosis construction on loess arrays, is essential for the normal functioning of buildings throughout their life cycle. If the removal of such dangerous phenomena as pseudokarst, subsidence and erosion are involved at the stage of design and construction, the development and manifestation of these processes during the operation in the buffer zones can cause deformation and even complete destruction of buildings. Therefore, requires monitoring buffer zones, which delimit technogenic changed territory (TIT) and ecological framework for preventive action reduce the negative impact of dangerous geological processes of natural and anthropogenic genesis.

Multi-sensor information fusion based control for VAV systems using thermal comfort constraints

The conventional control methods of variable air volume (VAV) air conditioning systems usually assume that the indoor air is well mixed, and consider each building zone as one node with homogeneous temperature distribution. The average temperature is subsequently used as the controlled parameter in the VAV cascade control process, which might cause uneven temperature distribution and unsatisfactory thermal comfort. This paper presents a coupled simulation of computational fluid dynamics (CFD) and building energy simulation (BES) for the VAV system in an office building located in Shanghai for the purpose of simulating the building, the VAV control system, and indoor thermal environment simultaneously. An external interface is developed to integrate the CFD and BES models based on quasi-dynamic coupling approach. Based upon the developed co-simulation platform, the novel VAV control method is further proposed by fusing information from multiple sensors. By adding two temperature sensors to constrain the thermal comfort of the occupied zone, the supply air temperature setpoint of the VAV terminal unit can be reset in real time. The novel control method is embedded into the co-simulation platform and compared with the conventional VAV control approach. The results illustrate that the temperature distribution under the proposed method is more uniform. At most times of the typical test day, the air diffusion performance indexes (ADPIs) for the proposed method are above 80%, while the ADPIs for the conventional control method are between 60% and 80%. Due to multi-sensor information fusion, the proposed VAV control approach has better ability to ensure the indoor thermal comfort.

Thermal - electrical analogy in dynamic simulations of buildings: Comparison of four numerical solution methods

The lumped capacitance method is widely used in dynamic modelling of buildings. Models differ in complexity, solution methods and ability to simulate transient behaviour of described objects. The paper presents a mathematical description of a simple 1R1C thermal network model of a building zone. Four numerical methods were applied to solve differential equation describing its dynamics. For validation purposes two test cases (600 and 900) from the BESTEST procedure were used. In both cases detailed results were given. Better ability of the simulation model to reproduce transient behaviour of the modelled buildings was noticed in case of the lightweight object (case 600). Annual heating and cooling demand was within the reference range for heavyweight one (case 900). The kind of the computation method had no significant effect on simulation results.