Load Factor Method Research Articles

Diseño y análisis dinámico de un edificio multifamiliar de 4 niveles sin sótano en la Provincia de Chanchamayo

In the present investigation, the design of a 4-story building without a basement located in the Province of Chanchamayo of Peru was carried out, intended for a multi-family home made up of structural elements such as columns, beams, and plates, which each one was designed and modeled under the Peruvian Load Regulations E. 020, Earthquake-resistant Design E. 030, Reinforced Concrete E. 060, Masonry E. 070 and General Design Conditions A. 010. The use of these Standards is established in the National Building Regulations that allowed compliance with the objective of designing and carrying out the Dynamic Analysis of the Building under the Earthquake methodology, which is based on the Load factor and resistance design method. Modeling was carried out with the help of ETABS software to obtain results necessary for the design and analysis of the structure. Finally, it was obtained that the building will use the structural system for structural walls, which has a basic reduction coefficient equal to 6 and it is concluded that the methodology used allows guaranteeing the safety, functionality and quality service of a building.

Aerodynamic Load Variation and Wind-Induced Vibration Analysis of Tower Cranes Under Full Wind Angles

When tower cranes are applied in coastal engineering, the wind-induced vibration under complex wind loads along the coast will be exceptionally obvious. It is increasingly important to explore the wind-induced vibration characteristics of different sections of tower cranes under full wind angles. This paper first establishes a three-dimensional numerical wind tunnel model that can be used for the simulation of tower cranes under full wind angles and analyzes the aerodynamic load variation of the tower crane under full wind angles. Secondly, the tower crane structure is divided into sub-regions, and the AR model method in the linear filtering method is used to simulate the three-dimensional wind speed time history. Further, the wind speed time history is applied to the finite element transient analysis, and based on the Newmark-beta method, the acceleration and displacement responses of different sections of the tower crane structure under fluctuating wind are systematically studied. Finally, the equivalent static wind load of different sections of the tower crane is evaluated by using the gust load factor method. The results indicate that the wind load of the tower crane exhibits an obvious three-dimensional effect, and the crosswind load cannot be ignored in the analysis of wind stability. The different sections of the tower crane structure show low-frequency vibration characteristics, and the low-frequency band is dominated by down-wind vibration, while the high-frequency band often experiences crosswind vibration. The amplification effect of the tower crane on fluctuating wind loads will increase with the increase of the height of the tower crane and the length of the jib, and the amplification effect on fluctuating wind loads in the crosswind direction is more obvious. The equivalent static wind load on the top of the tower crane reaches the maximum when the angle between the jib and the incoming wind is 60°.

Analysis of changes and trends in ambient air pollutant concentrations in the Beijing-Tianjin-Hebei region in recent years

The Beijing-Tianjin-Hebei region is a key prevention and control area for air pollution in China. Based on the PM2.5, PM10, SO2, NO2 and AQI data published by the Ministry of Ecology and Environment and the online monitoring and analysis platform of air quality, the temporal variation of air pollutant concentrations in the Beijing-Tianjin-Hebei region from 2019 to 2021 and the contribution of each pollutant to air pollution were analyzed by the comprehensive pollution index method and the pollution load factor method. The results show that: (1) The changes in the comprehensive air pollution index and AQI index in the Beijing-Tianjin-Hebei region from 2019 to 2021 show a downward trend. Compared with the annual average concentrations of PM2.5, PM10, SO2 and NO2 in 2019, the average concentrations of PM2.5, PM10, SO2 and NO2 decreased by 23.72%, 19.28%, 34.28% and 24.03%, respectively. (2) The monthly average change of the concentration of various pollutants in the Beijing-Tianjin-Hebei region from 2019 to 2021 shows a roughly shaped “U”, following the governing rule of "high in winter and low in summer, rising in autumn and falling in spring". (3) The average pollution load coefficients of four pollutants in the Beijing-Tianjin-Hebei region, including PM2.5, PM10, SO2 and NO2, were 38.18%, 31.64%, 3.84% and 26.34% from 2019 to 2021, respectively. It indicates that the ambient air quality in this area is greatly affected by particulate matter pollution.

Sustainability Assessment of Marine Aquaculture considering Nutrients Inflow from the Land in Kyushu Area

The nutrient load generated by excessive aquaculture farms leads to self-pollution around water, which destroys aqua-environment, and further leads to a decline in aquaculture production. The purpose of this study is to propose an index to assess the sustainability of inshore aquaculture in Kyushu area, considering nutrient loads from land and farms. The number and size of fish cages identified from Google satellite imagery are used to calculate annual fish production, which is then converted into annual loads of total nitrogen and total phosphorus. The pollutant load factor method is applied to calculate the land nutrient inflow. An index, including nutrient load from land and farms, bay area, water depth and distance from farms to bay, is proposed. The results show that for most of the cultured bays in Kyushu, the nutrient load from the farm is more than that from the land inflow. The bay with higher index value has a higher possibility of red tide occurrence and lower sustainability for aquaculture. Among which, location of fish farms, total nitrogen and total phosphorus loading are key factors impacting water quality within the bays.

Finite Element Analysis of the Load Factor and New Design Method for Bolted Joints Consisting of Dissimilar Hollow Cylinders Under Tensile Loads

Abstract In designing a bolted joint consisting of dissimilar hollow cylinders, the load factor (the ratio of an increment in axial bolt force to an external tensile load) is important. However, no researches on the characteristics of bolted joints consisting of dissimilar joint members have been conducted. In this paper, the effects of load application positions, the ratio b/a of the outside diameter to the inside diameter of dissimilar hollow cylinders, Young's modulus ratio between the dissimilar hollow cylinders on the load factor, and a load when the interface separation starts are examined using finite element method (FEM) calculations. As a result, it is found that the values of the load factor decrease as the ratio b/a increases, and the load application position approaches the interfaces, while the value of the load factor is independent of the bolt preload. For verification of the FEM calculations, experiments to measure the load factor and a load when the interfaces start to separate were carried out. The FEM results are fairly coincident with the experimental results. It is found that the value of the load factor is less than 0.15 for steel and aluminum joints, it is less than 0.1 for steel and steel joints, and it is less than 0.2 for aluminum and aluminum joints, where the bolt material is steel in this study. Finally, using the obtained load factor, a new design method for bolted joints with dissimilar hollow cylinders is demonstrated for determining the nominal diameter of bolt, the bolt strength grade, a target tightening torque, and a target bolt preload. Additionally, in the design procedure, an issue if a washer should be inserted or not inserted is discussed as well as determination of bolt preload.

Analysis of wind-induced responses and GLF for super-large cooling towers

Based on wind tunnel tests, time-varying wind pressure distribution on the finite element model of a super-large hyperbolic cooling tower under group-tower environment were reconstructed by the radial basis function (RBF) method. The results were applied in time-domain calculations of wind-induced responses of the cooling tower. Then, the gust loading factor (GLF) method adopted in current engineering practice was analyzed. The results indicate that: due to some inevitable limitations, the existing GLF scheme, in which a unified amplification factor G is adopted to calculate the equivalent static wind loads, may not be applicable for super-large cooling towers.

THE ANALYSIS OF PUBLIC NEEDS FOR RAIL TRANSPORT IN KRUENG GEUKUEH, ACEH, INDONESIA

This study aims to analyze the level of public demand for railroad transportation in Krueng Geukuh, Dewantara District, North Aceh Regency. The survey method used is the dynamic survey method and static survey, the data analysis method used is using the Load Factor method. The results showed that the travel speed using the Train was 5.3 minutes from each station. The time between the train distance and other public vehicles is 60 minutes. Travel time required in 1 km is 1.88 minutes. Keywords: Load Factor, Travel Speed, Headway, Travel Time, Frequency, Wakru Wait

RELATION OF SERVICE QUALITY, LOAD FACTORS AND TARIFF ON BUS CITY OF BANDUNG

The purpose of this study is to discuss the relationship between satisfaction with service quality, by determining the number of vehicles and the ideal tariff for passengers. This research was conducted on consumers who use the Bandung City Bus. The relationship between satisfaction and service quality with passenger loyalty using the Structural Equation Modeling (SEM) method, the ideal tariff is seen from the Ability and Willingness To Pay passengers compared to vehicle operating costs, the break-even load factor method is used to calculate the number of vehicles that consider passenger needs, revenue, and operational costs. The results of the calculation of service quality on satisfaction is 6,731, proving that service quality has a significant and positive influence on customer satisfaction. One of the dimensions of service quality is tangible include physical evidence has the higest correlation with satisfaction factors on the service quality dimension affecting passenger loyalty. Service satisfaction is obtained from vehicles are load factors, and tariffs, which are calculated from six non-toll routes in Bandung, with the Ability to Pay vehicle suitable tariffs, only route 6B shows the Willingness to Pay customers below the current tariff.Keywords: Service Quality; Customer Satisfaction; Load Factors, TariffJEL Classifications: L1, L8DOI: https://doi.org/10.32479/irmm.9867

Comparative Study of Building Envelope Cooling Loads in Al-Amarah City, Iraq

In recent years, the summer season in Iraq has become longer and hotter than before, leading to high cooling loads inside buildings and increased demand for electrical energy. The use of sustainable energy and insulation techniques for building envelopes are reasonable solutions for overcoming harsh weather conditions and reaching acceptable thermal comfort levels. In this study, a survey on more than 60 residential buildings in Al-Amarah City, Iraq, was conducted on 21 July 2018 to examine the nature of the most common construction materials used in the building envelopes. Furthermore, the cooling loads of building envelope elements, e.g. roof, external walls and windows, was calculated using the cooling load temperature difference/solar cooling load/cooling load factor method of ASHRAE. The results were tabulated and compared for each combination of elements. The results showed that reflective glass is the optimal choice for exterior windows. The 'clay"“insulation"“fired clay bricks"“cement mortar' and 'cement mortar"“thermo-stone bricks"“cement mortar"“gypsum mortar' combination layers performed well for roof and external wall installations, respectively. Several recommendations were deduced from this study, which can be used as guidelines for construction authorities in Al-Amarah City and individuals interested in energy-efficient buildings.

Theoretical and experimental development of cooling load temperature difference factors to calculate cooling loads for buildings in warm climates

In Mexico, electricity consumption is highest during the summer due to the usage of air conditioning systems. Considering that half of Mexico has warm climatic conditions and more than 30% households are equipped with some kind of air conditioning equipment, accurate cooling load calculations would directly affect energy efficiency, indoor thermal comfort and suitable heating, ventilation, and air conditioning design. The cooling load temperature difference/solar cooling load/cooling load factor (CLTD/SCL/CLF) method provides a reasonably accurate estimation of total heat gains through a building envelope; however, it is restricted to climatic conditions in the United States and a small number of construction materials. This study aims to determine the CLTD values for flat roofs and walls of buildings for different climatic zones in Mexico, such as Monterrey, Veracruz, and Mexicali, and for different construction materials that typically used in Mexico. We used the complex finite Fourier transform to solve the one-dimensional transient heat transfer model. We ran experimental setup in Monterrey to validate the mathematical model developed in this work. Additionally, we verified the theoretical model with the previously reported studies and compared them with CLTD values calculated using the correction factor proposed by the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) methodology. From these results, we can conclude that applying the CLTD method with the correction factor overestimates cooling loads through walls and roofs for typical buildings and Mexican climatic conditions. The average difference between ASHRAE-derived values and the obtained CLTD values was 10 °C.

Comparison of ASHRAE peak cooling load calculation methods

The building peak cooling load calculation is one of the fundamental steps to develop a proper whole-building HVAC system design. The accuracy of the calculation not only impacts the system size but also influences the building’s performance over the long run since oversized or undersized HVAC systems can exhibit less than optimal operation. Therefore, an accurate, easy-to-use method has been a goal for more than 60 years in the United States. To date, ASHRAE has published five methods for determining building peak cooling loads, including the total equivalent temperature difference/time averaging (TETD/TA) method, the transfer function method (TFM), the cooling load temperature difference/solar cooling load/cooling load factor (CLTD/SCL/CLF) method, the heat balance method (HBM), and the radiant time series method (RTSM). This article presents the results of a comprehensive comparison of these building peak cooling load calculation methods with a focus on the sensible building envelope cooling loads. The results show that the HBM is the most accurate method, followed by the RTSM, the TFM, the TETD/TA method, and the CLTD/SCL/CLF method.

Influence of Airflow Field on Food Freezing and Energy Consumption in Cold Storage

Currently most food products are cooled and frozen in air-blast cold storage to prolong storage time. The airflow field distribution in storage has a great impact on the process of food freezing and energy cost by that. In this paper, a transient model of food freezing considering airflow field was developed to simulation the temperature profile of air and food products during freezing process. A lumped parameter model was used to predict the temperature and moisture profile of air, which connected all other components together, such as air coolers, food products, envelop enclosure and refrigeration system. A finite difference method was employed to model the heat transfer inside food products during freezing, where the mass transfer was neglected as the food products were wrapped with polystyrene films. Unit load factor method was applied to calculate the sensible heat refrigeration capacity and thus the total capacity of air coolers. The simulation was conducted on a large cold storage filled with large quantities of packaged food products. Results show that there are great differences in airflow field distribution at different locations in cold storage, which lead to spacial differences in freezing time required. Inappropriate set point of freezing time prolongs freezing process unnecessarily and leads to extra energy consumption. Operational mode of air coolers has a great impact on the total energy consumption, as they consume energy themselves and release equivalent heat into storage simultaneously.

Literature review of building peak cooling load methods in the United States

Today, sizing HVAC systems plays an important role in the building design process, requiring an accurate method in order to avoid problems from over- or under-sized systems. To date, there have been five peak cooling load methods published by ASHRAE, including: the Total Equivalent Temperature Difference/Time Averaging Method, the Transfer Function Method, the Cooling Load Temperature Difference/Solar Cooling Load/Cooling Load Factor Method, the Heat Balance Method, and the Radiant Time Series Method. This study provides a thorough review of the five methods with respect to their history and summarizes the method differences that can lead to inaccurate sensible cooling load calculations.

Comparative Study on Implementing Home Air Conditioning for Passenger Carriages in the Indonesian Railway

Passenger comfort is important in railway transport system. The train operator company in Indonesia would like to increase passenger comfort by installing home air conditioning into all existing carriages of the economy train. The air conditioning is expected to give better passenger convince. Therefore, the aims of this research are to know the cooling load and compare characteristic between home Air Conditioning (AC) and train AC. The cooling load calculation is analyzed using Cooling Load Temperature Difference (CLTD)/Solar Cooling Load (SCL)/Cooling Load Factor (CLF) method. Comparison between both home air conditioning and train air conditioning are discussed to identify the benefits and drawbacks of each type. The total heat that needs to be removed from a passenger carriage with home AC is 104,334 Btu/h, while the total cooling capacity of home AC is 75,000 Btu/h. The passenger carriages with train AC have cooling capacity 119,100 Btu/h to remove heat 11,5290 Btu/h. The Energy Efficiency Ratio (EER) value of most home AC is higher than train AC, installation time of home AC is shorter than train AC, total cost for 20 years period of home AC is more than train AC. There is no guarantee for home AC, so everything that happens to it will become the full responsibility of train operator company. The train AC control system is more effective than the home AC. No fresh air is permitted to circulate within the home AC system hence, the same air is repeatedly processed in the system. Implementing home air conditioning in the existing passenger carriages is worthwhile for short time period in the goal to increase and improve the level of service provided by giving better comfortability to the passenger.

Study on the Urban Air Quality Assessment and Pollution Characteristics in Daqing City

The aim of this study is to reveal the spatial and temporal variations of the main atmospheric pollutants in Daqing City by mathematical analysis of the monitoring data according to the atmospheric environmental monitoring data for nearly 15 years of Daqing City. The comprehensive pollution index method, the pollutant load factor method and the rank correlation coefficient method were used for the evaluation of atmospheric environmental quality. The results showed that the air quality of Daqing City was good as a whole in 15 years and it improved better step by step. Dusts and PM10 were the major air pollutants and the weight of NO2 was increasing year by year. In addition, the air pollution type was developing from “coal smoke” to “oil smoke”. Spearman rank correlation coefficient method was used to analyze the trend and significance of the main air pollutants in Daqing City. The results showed that PM10, dusts and SO2 presented downward trend and NO2 Presented upward trend, but the trends were not significant and fluctuated on the same level. The task of energy-saving and emission-reduction will be still arduous for Daqing City.

Wind-induced responses of super-large cooling towers

Traditional gust load factor (GLF) method, inertial wind load (IWL) method and tri-component method (LRC+IWL) cannot accurately analyze the wind-induced responses of super-large cooling towers, so the real combination formulas of fluctuating wind-induced responses and equivalent static wind loads (ESWLSs) were derived based on structural dynamics and random vibration theory. The consistent coupled method (CCM) was presented to compensate the coupled term between background and resonant response. Taking the super-large cooling tower (H=215 m) of nuclear power plant in Jiangxi Province, China, which is the highest and largest in China, as the example, based on modified equivalent beam-net design method, the aero-elastic model for simultaneous pressure and vibration measurement of super-large cooling tower is firstly carried out. Then, combining wind tunnel test and CCM, the effects of self-excited force on the surface pressures and wind-induced responses are discussed, and the wind-induced response characteristics of background component, resonant component, coupled term between background and resonant response, fluctuating responses, and wind vibration coefficients are discussed. It can be concluded that wind-induced response mechanism must be understood to direct the wind resistant design for super-large cooling towers.

ANALISIS PERSEPSI AUDITOR MENGENAI FAKTOR PENENTU AUDIT FEE BERDASARKAN CLIENT ATTRIBUTES, AUDITOR ATTRIBUTES, DAN ENGAGEMENT ATRTRIBUTES

This research purposes to know how perception auditors about determining factors of audit fee based on Client Attributes, Auditor Attributes, and Engagement Attributes at The Public Accountant Firm residing in Bandung. In this research, the indicator that is used to characterize the Client Attributes are size, complexity, inherent risk, profitability, leverage and liquidity, and industry. While the indicator to characterize the Auditor Attributes are auditor’s specialization, audit tenure, and location. And the indicators to characterize the Engagement Attributes are audit problems, audit report lag, busy season, and number of reports. The Method that is used in this research is a descriptive method. The population in this research is a public accountant in Bandung. Based on sampling techniques that saturated and qualified then it take about 11 offices of public accountant. SmartPLS ver 2.0 M3 are used as a Statistical analysis. The result of this research with count the loading factor and bootstrapping method are, the first one that the perception of the auditor based on client attributes of audit fee determinants from which is very important to not important is size, complexity, profitability, inherent risk, industry, and leverage & liquidty, the second states that perception based on auditor attributes audit fee determinants from which is very important to not important is audit tenure, location, and specialization. And the third states that the perception of auditor engagement attributes based determinants of audit fee which is very important to not important audit report lag, busy season, audit problems and number of reports.

A simplified method to predict hourly building cooling load for urban energy planning

It is not feasible to apply the traditional prediction method to predict hourly building cooling load at the urban energy planning stage because of the limited building information and complexity of energy prediction. This paper presents a simplified prediction model: Hourly Cooling Load Factor Method (HCLFM) that can provide quick and fair estimate of building cooling load for large-scale urban energy planning. The paper introduces the assumptions and principles of the proposed method, as well as discussing the implication and limitation of the approach. As a verification and demonstration, the method is applied to an office building in Beijing. The predicted results show that the dynamical trend of the cooling load is reasonable. The study further analyzes the potential causes of prediction errors and the significance of various cooling load influence factors.

Engineering Design of a Multiple-Use Spherical Explosion Containment Vessel Subjected to Internal Blast Loading From 25 kg TNT High Explosive

Explosion containment vessels have been widely used to contain the internal blast effects. In this paper, we present engineering design and experimental results of a real multiple-use spherical explosion containment vessel, which has been employed to withstand internal blast loading from 25 kg trinitrotoluene (TNT) high explosive in the past 10 years. It is shown that strain growth should be considered in the analysis and design of multiple-use explosion containment vessels, and the dynamic load factor (DLF) method with the consideration of strain growth may achieve a safe and proper design.

Bridge Rating Using System Reliability Assessment. II: Improvements to Bridge Rating Practices

The current bridge-rating process described in AASHTO Manual for Bridge Evaluation, First Edition permits ratings to be determined by allowable stress, load factor, or load and resistance factor methods. These three rating methods may lead to different rated capacities and posting limits for the same bridge, a situation that has serious implications with regard to public safety and the economic well-being of communities that may be affected by bridge postings or closures. This paper is the second of two papers that summarize a research program to develop improvements to the bridge-rating process by using structural reliability methods. The first paper provided background on the research program and summarized a coordinated program of load testing and analysis to support the reliability assessment leading to the recommended improvements. This second paper presents the reliability basis for the recommended load rating, develops methods that closely couple the rating process to the results of in situ inspection and evaluation, and recommends specific improvements to current bridge-rating methods in a format that is consistent with the load and resistance factor rating (LRFR) option in the AASHTO Manual for Bridge Evaluation.