Constraint Factor Research Articles

Compilation of 1:50,000 vegetation type map with remote sensing images based on mountain altitudinal belts of Taibai Mountain in the North-South transitional zone of China

The compilation of 1:250,000 vegetation type map in the North-South transitional zone and 1:50,000 vegetation type maps in typical mountainous areas is one of the main tasks of Integrated Scientific Investigation of the North-South Transitional Zone of China. In the past, vegetation type maps were compiled by a large number of ground field surveys. Although the field survey method is accurate, it is not only time-consuming, but also only covers a small area due to the limitations of physical environment conditions. Remote sensing data can make up for the limitation of field survey because of its full coverage. However, there are still some difficulties and bottlenecks in the extraction of remote sensing information of vegetation types, especially in the automatic extraction. As an example of the compilation of 1:50,000 vegetation type map, this paper explores and studies the remote sensing extraction and mapping methods of vegetation type with medium and large scales based on mountain altitudinal belts of Taibai Mountain, using multi-temporal high resolution remote sensing data, ground survey data, previous vegetation type map and forest survey data. The results show that: 1) mountain altitudinal belts can effectively support remote sensing classification and mapping of 1:50,000 vegetation type map in mountain areas. Terrain constraint factors with mountain altitudinal belt information can be generated by mountain altitudinal belts and 1:10,000 Digital Surface Model (DSM) data of Taibai Mountain. Combining the terrain constraint factors with multi-temporal and high-resolution remote sensing data, ground survey data and previous small-scale vegetation type map data, the vegetation types at all levels can be extracted effectively. 2) The basic remote sensing interpretation and mapping process for typical mountains is interpretation of vegetation type-groups→interpretation of vegetation formation groups, formations and subformations→interpretation and classification of vegetation types & subtypes, which is a combination method of top-down method and bottom-up method, not the top-down or the bottom-up classification according to the level of mapping units. The results of this study provide a demonstration and scientific basis for the compilation of large and medium scale vegetation type maps.

Performance of four state-of-the-art GPP products (VPM, MOD17, BESS and PML) for grasslands in drought years

Accurate estimation of gross primary production (GPP) is of significance for understanding the changes of carbon uptake and its responses to extreme climate events like droughts. Emerging new GPP products with higher spatial and temporal resolutions (500-1000 m, 8-day) from the Moderate Resolution Imaging Spectroradiometer (MODIS) Photosynthesis (MOD17), the Vegetation Photosynthesis Model (VPM), the Breathing Earth System Simulator (BESS), and the Penman-Monteith-Leuning (PML) models, provided unprecedented opportunities to understand the spatial and temporal variations of GPP. However, their performances under drought conditions remain obscure. Here we evaluated the performance of these four state-of-the-art GPP products in grasslands, using FLUXNET data as reference. The results showed that all the four models have reasonable accuracies under non-drought years. In drought years, the VPM performed best, followed by the MOD17, PML and BESS, with the RMSEs of 1.67, 1.69, 1.72 and 1.77 gC m−2 day−1, respectively. The VPM, BESS and PML overestimated annual GPP by 2%, 13% and 21%, respectively, while MOD17 underestimated annual GPP by 10% in drought years. This varied model performances under drought years could be partially attributed to the differences in quantifying the water stress effects. The water constraint factor in the VPM, which is derived from the Land Surface Water Index (LSWI) and directly indicates the overall water content of leaf, plant stand and soil background, could better capture the vegetation response to water content variation than that in MOD17, PML and BESS, all of which used an atmospheric moisture related indicator (the Vapor Pressure Deficit for MOD17 and PML, and the relative humidity for BESS). This study suggests that water stress factors, which reflect the physiological and ecological characteristics of vegetation itself (e.g., LSWI) rather than atmospheric moisture (e.g., VPD) or other meteorological surrogates, should be further considered in GPP models when applied in drought conditions

Genetic Algorithm Based Prototype Filter Design for Oriented Side Lobe Energy Suppression in FBMC System

The prototype filter design problem is investigated for the filter bank multicarrier (FBMC) system of the fifth generation (5G) physical-layer wireless communications. In order to further suppress the side lobe energy within a certain frequency range, different constraint factors need to be introduced to meet the various side lobe energy suppression demands. In this paper, we formulate a dual-objective optimization problem which minimizes the stopband energy with constrained factors and subjects to the ISI/ICI constraints. Considering the uncertain constrained factors, a suboptimization problem is proposed by constraining the total stopband energy and the side lobe energy of the first segment to minimize the side lobe energy of the second or the third segments. Then, the nested sequential quadratic program-genetic algorithm (NSGA), one of the artificial intelligence (AI) aided algorithms, is introduced to obtain the optimal solution of the dual-objective problem, in which the genetic algorithm (GA) is applied to acquire the optimal constrained factors and the sequential quadratic program (SQP) is applied to acquire the optimal filter coefficients. Numerical results validate that the proposed method can achieve orientated side lobe energy suppression at specified segments for satisfying different side lobe energy suppression requirements with the confirmed algorithm convergence.

Organizational and technological solutions of multicriteria quality analysis in high-rise construction

Features of renovation of built-up areas are considered. The main difficulties in carrying out the renovation process are identified. The concept of the constraint factor of the building is defined. Methods. A method for analyzing and assessing constraints for selecting optimal organizational and technical solutions for the renovation of territories is proposed. Results. An analysis algorithm is proposed, based on the consideration of the constraint factor as an array of actions of individual “objects of influence” on the corresponding “subjects of influence”. Conclusion. Сonducting such an analysis will provide the most effective and optimal organizational and technological solutions reflected in the relevant sections of the renovation project in high-rise construction (development of a construction master plan, preparation of calendar and network work schedules). The implemented rational version of the design solution ensured the reduction of the prime cost and the reduction of the terms of the preparatory works for the renovation of housing construction projects taking into account seismic uncertainty. Renovation is one of the varieties of this reconstruction of high rise construction.

Study on the impact of LNG carrier entering and leaving port on the passing capacity of narrow channel

As a clean energy source, LNG has been widely used. LNG ships need to enter and leave the port area through the channel. With the development of the port, the ship traffic will gradually increase. As a manual excavation of narrow and long channel, its passing capacity will become a constraint factor for LNG receiving stations and port development. In this paper, the system simulation method is used to study the impact of LNG ship entry and exit on the passage capacity of the channel, which can provide basis and reference for the planning, site selection and channel construction of the LNG receiving station.

Study on Constraint on the Readiness of Using Building Information Modelling (BIM) for Construction Project in Indonesia

Building Information Modeling (BIM) is a paradigm shift that has many benefits, not only for those engaged in building construction but also for the wider community. The benefits of BIM include a more integrated design and construction process, resulting in better quality buildings, lower costs and lower duration. However, to master BIM in Indonesia, many factors have not been achieved. This study uses the Analytical Hierarchy Process (AHP) to get the constraint factors for the readiness of using BIM in Indonesia which consists of 3 criteria in which there are 19 sub-criteria. There are 5 (five) experts who have competence in the field of building Information Modeling with at least 10 years of experience carrying out the assessment. The results of expert research show that the most dominant factors on the readiness of using BIM are Maturity in Understanding BIM.

Key Factors Influencing Multimodal Transportation of Natural Block Rubber in Thailand

Thailand is the world’s largest natural rubbers exporter. The major type of natural rubbers exported is block rubber. Currently, the transportation of natural rubbers in Thailand depends mainly on truck mode because of the convenience and extensive network of roads. However, Thailand confronts road transportation limitations including maximum acceptable weight, traffic congestion and high fuel prices. Dealing with these problems, the multimodal connection from roads to container yards (CY) and ports is expected to decrease logistics cost, and increase various opportunities to trade with neighbouring countries. This paper, thus, aims at examining key factors influencing the use of multimodal transportation utilizing the exploratory factor analysis (EFA). The principal components analysis (PCA) method, together with the eigenvalue over 1, factor loading of 0.40, and varimax rotation method, extracted five key factors with a total of 20 associated attributes, which are the Multimodal Operation, Service Operation, Multimodal Service Provider, Market Consideration, and Road Constraints factors. The result also pinpoints the capacity of container yard (CY) or port, accessibility to container yard (CY) or port, documentation process, logistics cost, adequacy of a multimode service provider, and law enforcement on truck driving hours, as crucial attributes in planning for multimodal transportation. This paper can be used as a guideline for a feasibility study of multimodal transportation of natural block rubber in Thailand.

Experimental approach for the study of wood strength at fracture in mode II by using a modified prototype test specimen and confrontation of the results with those of the 4ENF test. Application: Eucalyptus Grandis

Wood is a material used since the beginning of history by Man, It has proved very practical in various fields, and we quote mainly the sector of building and furniture. Known to be anisotropic, cellular and very complex. Its structural properties have a major influence on the mechanical behavior of the material. The interest of this present work is to further enrich our knowledge of this material through the study of its behavior in the face of external stresses that generate the mode II fracture. To do this, the choice of a specimen to study is imperative, knowing that there is no standardized test for the study of this phenomenon; we then began by studying the different prototypes of specimens mentioned in the literature and identified their advantages and disadvantages. We concluded that each test presents many difficulties of use and a great dispersion of the results caused on the one hand, by the nature of the material but mainly by the instability of the propagation of the crack. Based on this state of the art and the various experimental devices available to us, we have developed a test specimen prototype based on a tensile test for the study of the mode II of fracture. To carry out this work, in order to apprehend the studied material, we began by carrying out a complete characterization of the studied essence: Eucalyptus Grandis that includes the two aspects: mechanical and physical.. The dispersive nature of the material, the tests of the feasibility of the prototype developed and the number of notches require the reproduction of the test, hence the large amount of testing. During this test, the wood has adopted a fragile character, which gives it a linear behavior until it reaches a break with a stable propagation of the crack. This has been noticed for all notch lengths. The microscopic analysis that we carried out enabled us to validate the mode of fracture, to do this we studied the fracture facies of each length of notch using the scanning electron microscope. To determine the GII energy mode II initiation fracture toughness, we used the global approach using the convenience method and the theory of IRWIN KIES, we then deduced the KII constraint factor. We wanted to compare the results obtained with those of the literature but this operation can hardly be feasible except for the case, if we compare that order of magnitude because the tests are not done under the same conditions and using even the species. This led us to reproduce the most used test in the research and which is more accurate compared to other experiments in this case the test 4ENF.

基于Lagrange约束因子修正迭代初值的TDOA定位算法

基于Lagrange约束因子修正迭代初值的TDOA定位算法

Factors Affecting the Implementation of Low- Level Oral Questioning in Mathematics Teaching in Primary School

The purpose of this study was to identify factors that influence the implementation of low-level oral questioning in mathematics teaching in primary school. This study was a qualitative study using the case study method. Data were collected through partial structural observation, semi-structured interview, document analysis and field notes. Six mathematics teachers from six different primary schools were selected as participants of the study using purposive sampling method. The data were then analyzed using a constant comparative method to identify the patterns and themes that emerged from the data obtained. The study identified that factors of time constraint, heavy workload, extensive coverage of contents, low level student achievement, student engagement, and lack of in-service training contributed to the lack of high level questionings in the mathematics teaching process. These factors need to be addressed so that students' thinking can be enhanced through higher level oral questioning activities during the class.

Suitability of constraint and closure models for predicting crack growth in generic configurations

The effective stress intensity factor range ΔKeff is commonly considered to govern the fatigue crack growth and may be estimated through the crack opening stress Sop and the constraint factor α. In the literature closed-form expressions have been developed for estimating both variables in a center-cracked plate with elastic-perfectly plastic behavior subjected to remote uniform stresses. However, such expressions are frequently adopted regardless of geometry, material and loading and, moreover, α is often given a fixed value. The final objective is to assess the suitability of existing constraint and closure models for performing accurate crack-growth predictions in configurations that do not meet the original hypotheses. The region-II growth of a hole-edge crack is predicted in the 42CrMo4 steel by integrating crack growth laws calibrated with data from standard compact tension (CT) specimens. The results show overall better predictions by using the same constraint model for estimating α in both geometries, rather than by treating it as a fitting parameter in CT specimens. Unexpectedly, the predictions obtained at different stress ratios were, in general, more accurate by integrating a non-closure law based on ΔK and independent of Sop and α.

Governing convergence of Max-sum on DCOPs through damping and splitting

Max-sum is a version of Belief Propagation, used for solving DCOPs. In tree-structured problems, Max-sum converges to the optimal solution in linear time. Unfortunately, when the constraint graph representing the problem includes multiple cycles (as in many standard DCOP benchmarks), Max-sum does not converge and explores low quality solutions. Recent attempts to address this limitation proposed versions of Max-sum that guarantee convergence, while ignoring some of the problem's constraints. Damping is a method that is often used for increasing the chances that Belief Propagation will converge. That being said, it has not been suggested for inclusion in the algorithms that propose Max-sum for solving DCOPs.In this paper we advance the research on incomplete-inference DCOP algorithms by: 1) investigating the effect of damping on Max-sum. We prove that, while damping slows down the propagation of information among agents, on tree-structured graphs, Max-sum with damping is guaranteed to converge to the optimal solution in weakly polynomial time; and 2) proposing a novel method for adjusting the level of asymmetry in the factor graph, in order to achieve a balance between exploitation and exploration, when using Max-sum for solving DCOPs. By converting a standard factor graph to an equivalent split constraint factor graph (SCFG), in which each function-node is split into two function-nodes, we can control the level of asymmetry for each constraint.Our empirical results demonstrate a drastic improvement in the performance of Max-sum when using damping (referred to herein as Damped Max-sum, DMS). However, in contrast to the common assumption that Max-sum performs best when converging, we demonstrate that non converging versions perform efficient exploration, and produce high quality results, when implemented within an anytime framework. On most standard benchmarks, the best results were achieved using versions with a high damping factor, which outperformed existing incomplete DCOP algorithms. In addition, our results imply that by applying DMS to SCFGs with a minor level of asymmetry, we can find high quality solutions within a small number of iterations, even without using an anytime framework. We prove that for a factor graph with a single constraint, if this constraint is split symmetrically, Max-sum applied to the resulting cycle is guaranteed to converge to the optimal solution. We further demonstrate that for an asymmetric split, convergence is not guaranteed.

Designing of organizational and technological solutions for construction in constrained urban environments

The article substantiates the need to improve the quality of design work on the construction site in the context of the existing urban development taking into account specific criteria and gradations. The features and problems of the main periods of construction are investigated. To improve the quality of the design documentation, in particular, of the construction work program in constrained urban conditions, the authors conducted the research of the influence of a complex of constraint factors affecting construction preparation activities. Recommendations of construction site organization in the current conditions are given. The results are presented and further research stages of technological processes in constrained urban conditions are outlined. We show the expediency of a systematic approach to improving the quality of construction’s process. We are taking into account the assessment of environment state and the need to reduce the negative impact of construction and assembly works on nearby already built-up areas. The need to take into account the above factors for developing a project of works execution is justified.

한국 의료관광의 제약요인과 성공가능방안에 관한 연구: 근거이론적 접근

Korean medical tours are growing dramatically as the globalization trend of medical tourism continues. There are, however, constraint factors which hinder the success of Korean medical tourism. This study has its aim to review the constraint factors of Korean medical tourism, and to introduce few yet significant implications on viable measures. Based on the interviews with 10 experts leading the development of Korean medical tours at the site of Korean medical tourism, data has been collected. The collected data was analyzed by Strauss and Corbin

Dynamic ball indentation for powder flow characterization

In industrial processing and manufacturing, characterizing the flowability of particulate solids is of particular importance both for reliable powder flow and for a consistent production rate. Shear testing is the most widely used method for powders subjected to moderate or high stresses, and under quasi-static conditions. However, this method is not suitable for measuring the powder flow properties occurring in dynamic systems, such as powder mixers and screw conveyors. In this study, the rheological behaviour of powders at high shear rates has been evaluated by the ball indentation method. The technique, which simply consists of dropping a ball onto a cylindrical bed of previously consolidated powder, directly measures the material hardness, which is related to the unconfined yield stress by the constraint factor. The impact of the ball on the bed is recorded with a high-speed camera to determine velocity and penetration depth. The hardness against the strain rate is considered for four different materials. Because of their difference in particle size, and by using a range of drop heights and a range of indenter densities, the intermediate regime of flow has been fully analyzed. Although hardness is constant in the quasi-static condition, it results to be strain rate dependent in the intermediate regime of flow. Finally, a predictive correlation that allows the operator to choose the best operating conditions for achieving the desired flow regime is proposed, and the unconfined yield strength of the materials is inferred.

The Impact of Auditor Switch on Private Sector’s Financial Constraints during the Implementation of the PPP Contract: Empirical Analysis Based on PSM-DID Model

Government intervention is the primary reason for the failure of PPP projects in China. Therefore, project implementing agencies should “loosen the shackle” of social capital or project companies (private sector), so as to give full play to their subjective initiative and innovative spirit. Practically, however, the winning of the social capital or the project company in the implementation of the PPP will tend to take opportunism behaviour in order to increase their income, resulting in the phenomenon of “the winner’s curse”, so the project implementing agencies still need through inspection, testing, auditing, and other ways to supervise and control the social capital or the project company. Based on the above research background, It will be of great significance to explore the impact of auditor changes on the subsequent financing constraints of the private sector during the implementation of PPP contracts. Using data from listed companies participating in PPP project construction from 2000 to 2017, through the PSM-DID model, we find that: After eliminating the selectivity bias, auditor changes result in additional costs of debt; Audit opinion shopping, accompanied by auditor changes, makes listed companies face greater debt financing constraints during the implementation of the PPP contract. The results of this study enrich the research on the influence factors of corporate financial constraints and the corporate governance mechanisms of audit market, and reveal the effectiveness of audit supervision in PPP mode to improve project management efficiency and project operation.

Soil Fertility Evaluation for Strategic Direction Jati Plus Perhutani (JPP)

Soil fertility evaluation conducted to assess the characteristics of the soil and determine the significant constraint factor and alternative supervision. This research aims to determine the limiting factors of soil fertility in Jati Plus Perhutani (JPP) clonal forestry and routine plantation at the research sites in a few years of planting and determining the strategic directives of supervision. Total land of 12 soil map units evaluated based on a representative profile in the semi-detail level on the research sites of FMU Ngawi and Pemalang. Data collection of soil fertility was based on Soil Research Institute and the National Soil Survey Center guidelines. Classification of soil fertility shows that the soil was dominated by silty texture and has a flat to a moderately steep slope. Soils at the research sites have low infiltration rates, high ability to restrain water, difficult cultivation, and a high potential for a run-off on sloping land. Assessment of soil fertility status at the research sites shown of CEC and base saturation high to very high. C organic, P2O5, and K2O are rated very low to low, strategic directives for land supervision and cultivation in the research sites are the application of organic substances, intensive soil management and implementation of soil conservation.

How does ecology of finance affect financial constraints? Empirical evidence from Chinese listed energy- and pollution-intensive companies

Abstract Investment and financing are crucial for the healthy development of modern enterprises. A series of recent studies have examined various influential factors of financial constraints of enterprises, but few researchers have incorporated the influential factors simultaneously. This study introduces the term ecology of finance as a synthesized indicator to measure the influences of a series of variables that may affect financial constraints simultaneously. Using the data of Chinese A-share listed energy- and pollution-intensive firms from 2007 to 2017, how and to what extent the ecology of finance affects financial constraints is quantitatively investigated. The main finding of this research is threefold. First, good internal ecology of finance can relieve the financial constraints of high-polluted and high energy consumption firms, and improved external ecology of finance intensifies the financial constraints. Second, firms with high-level internal ecology of finance are more sensitive to the change in external ecology of finance. Third, firms with a lower level of external ecology of finance are affected more by the change in internal ecology of finance. This study provides insights on how to formulate appropriate policies and regulations for energy- and pollution-intensive companies to relieve their financial constraints and improve their environmental performance.

The impact of consumers' time constraint and conspicuous consumption behaviour on the throwaway society

AbstractIn highly competitive economies, productivity is always increasing as entrepreneurs, driven by the profit motive, strive to build a better mousetrap. Over time, this has given consumers a wealth of material goods. However, within this type of economy, the consumers need to consume all that is produced or else there will be distortions in the labour markets. However, as it turns out, we are able to consume all that is produced by having transitioned into a throwaway society, but there are environmental consequences associated with the replacing of malfunctioning household products instead of repairing and reusing these products. There are a number of factors responsible for causing consumers to replace a malfunctioning household product as opposed to repairing the product for reuse. The research in this paper will focus on two of these factors. The first factor is the time constraint that consumers are faced with and the second factor is conspicuous consumption. This research uses the results of an international survey conducted in seven different countries at different stages of economic development. The survey was conducted between November, 2015 and December, 2016. The results show that both the time constraint factor and the conspicuous consumption factor are significant in determining that if a consumer will look to replace a malfunctioning household product as opposed to repairing the product for further reuse. Furthermore, as more nations continue to develop economically and their GDP per capita grows, then the environmental impacts resulting from an increasing throwaway society by those nations will yield more hazardous environmental consequences.

Investigation of powder flowability at low stresses by DEM modelling

Ball indentation is a technique capable of assessing powder flowability down to very low consolidation stresses (≤1 kPa). With this method, powder flowability is determined by measuring the hardness of a powder bed, which allows the unconfined yield strength to be inferred via the constraint factor. The latter is well established for continuum materials, whereas for particulate systems its dependency on stress level and powder properties is not well defined. This work investigates these factors by simulating the ball indentation method using DEM. The constraint factor is shown to be independent of pre-consolidation stress. Constraint factor generally increases with interface energy for relatively cohesionless powders, though not for cohesive powders. An increase in plastic yield stress leads to a decrease in the constraint factor. Increasing the coefficient of interparticle static friction reduces the constraint factor, while increasing the coefficient of inter-particle rolling friction significantly increases the constraint factor.