15 research outputs found
Effect of torsion on shear capacity of slabs
No full textA large number of existing bridges in Europe and North-America are reaching the end of their devised service life. Therefore, it is necessary to improve the methods of assessment for existing bridges. One method, suitable for existing reinforced concrete slab bridges, is the Modified Bond Model. This method, however, currently only takes the effect of torsion for loads close to the edge into account in a simplified manner. In this study, finite element models are created of a slabs with two supports, three concentrated (pre-stressing) loads and a distributed load, representing a truck wheel print. The load is varied along the longitu-dinal and transverse directions of the slab to find the bending moments (mx and my) and torsional moments (mxy). The results is an expression for the effect of torsion in slabs, which can be used with the Modified Bond Model for assessment and design of slab bridgesSteel & Composite Structure
Safety Risk Management in Dam Construction Projects: Literature Review
No full textSafety risk assessment in dams is a traditional and modern approach to the engineering process of dams on safety systems so as to produce a design history that has a good overall record and integrity. With this approach for both old and new dams, this safety risk assessment aims to determine whether the risk the hazard can be tolerated or not, if it cannot be tolerated then there must be a solution for action to reduce the risk of danger so that the safety of the dam can be obtained. The existing risk assessment can be used as the basis for the construction of the dam to its maintenance, in this study discussed risk assessment safety on dams located in several countries such as in Asia, Europe and America. The methods implemented include the preparation of safety risks, risk analysis, risk evaluation and safety risk management. Based on research results The main risk factor that causes safety responsibilities is the Contractor\u27s responsibility, namely the Non-technical project factor (40.54%), the 2nd rank is the Undecided Responsibility due to internal technical factors (35.13%), the 3rd rank is the technical project factor namely Contractor\u27s Responsibility (10.8%), Rank 4 is external technical factor and external non-technical factor, the last risk factor is internal non-technical factor (2.7%) namely Joint Responsibility.
Keywords : Risk safety management, risk assessment, risk analysis, risk evaluation, dam projec
Bankruptcy Prediction with Rough Sets
No full textThe bankruptcy prediction problem can be considered an or
dinal classification problem. The classical theory of Rough Sets describes
objects by discrete attributes, and does not take into account the order-
ing of the attributes values. This paper proposes a modification of the
Rough Set approach applicable to monotone datasets. We introduce re-
spectively the concepts of monotone discernibility matrix and monotone
(object) reduct. Furthermore, we use the theory of monotone discrete
functions developed earlier by the first author to represent and to com-
pute decision rules. In particular we use monotone extensions, decision
lists and dualization to compute classification rules that cover the whole
input space. The theory is applied to the bankruptcy prediction problem
CRITICAL SUCCESS FACTORS FOR MODULAR CONSTRUCTION ON HIGH-RISE RESIDENTIAL BUILDINGS BASED RISK MANAGEABILITY TO INCREASE PROJECT TIME PERFORMANCE
No full textInternational Construction Costs published in Comparison 2020 continued to increase as an impact of the Covid-19 pandemic, The modular system is considered able to answer the problems of increasing costs. Although modular construction has been widely applied to low-rise buildings, application in high-rise buildings remains limited, less than 1% worldwide. The need for residential high-rise building applying modular construction in Indonesia becomes important. The interdependence between parties in modular projects is greater than in conventional methods. Unavailability of design guidelines hinders the construction industry in implementing modular technology. The purpose of this study is to analyze the critical success factors for modular construction of residential high-rise buildings applying risk-based management to improve project time performance. Forty-one Indicators were drawn from literature reviews and specialist interviews to conduct a sustainability evaluation. The survey was submitted to case project developers, designers, supervisors, and contractors in Indonesia, thereafter statistically analyzed using SPSS and risk management analysis with three stages: risk sources, risk drivers and risk causes. Critical success factors for drawing approvals have a considerable influence on modular construction among 15 other factors, followed by supply chain and design standardization. It is necessary to mitigate these risks to improve project time performance
Guidance and Control for Re-entry Vehicles in the Terminal Area: Application of Pseudospectral Methods
No full textOne part of spaceflight technology that has always been in demand is to go to space using a vehicle that can be re-used without much additional costs. It is roughly five years ago that the last Space Shuttle mis- sion took place, and replacements are currently in development. Yet, much of the available literature is still based on architectures created during the development of the Space Shuttle. The goal of this thesis is to expand the current knowledge with modern computational methods. This thesis demonstrates if pseudospectral methods can be used as the basis of a guidance and control architecture in the terminal area. In the past, these architectures were based by decoupling the longitu- dinal and lateral dynamics, using the energy available to calculate the current state without knowing what is to come, and calculating many variables and possible scenarios before the flight has even commenced. The architecture presented here does not require this, and it demonstrates an integrated package that can do this on the fly, by deploying a type of non-linear optimization method called pseudospectral methods. The X-38 is chosen as the reference vehicle due to the compatibility of the aerodynamic data set with non- linear optimizers. A 3-DOF simulation is created to see what set of feasible trajectories can be created un- der nominal conditions. Subsequently, a single reference trajectory is used as a basis to determine if the guidance subsystem is able to cope with a wide variety of initial conditions. The guidance system proved to be quite robust. A set of winds and gusts have been simulated and it would return to the desired state as long as there is an approximate predictive ability. The research is later continued by extending to a 6-DOF simulation. A control subsystem based on LQR is implemented with good results. A PSM implementation is introduced after and the results are promising, but the computation time is too high to be feasible. The upside is that a result is found without calculating the deflection of the trimmed state and gains, which was required with LQR. The conclusion is that pseudospectral methods can be used as a robust real-time guidance method, but that using it as a control method is currently not feasible. It is thus proven that pseudospectral method is able to deal without calculating predictive trajectories and gains as was done with the Space Shuttle. This reduces the complexity of re-entry problems by a sub- stantial amount. The time it takes to solve problems with new conditions and spacecraft is reduced, which might encourage other people to continue in this direction. There is still much more possible than what is presented in this thesis.Aerospace EngineeringSpace EngineeringSpace Exploratio
Análise de indicadores e sua influência no resultado dinal dos jogos do campeonato brasileiro de futebol da série A 2011
No full textO presente estudo buscou identificar dentre as variáveis estudadas, quais melhor explicam o resultado final do jogo de Futebol. A amostra foi constituída por 380 jogos do Campeonato Brasileiro de 2011. Os dados foram obtidos de forma indireta e cedidos pela empresa “Footstats”, especializada em análise estatística de Futebol. As variáveis do estudo foram local do jogo (mando de campo), posse de bola, passe certo e passe errado, definidas por interesse do autor. Para a apresentação do perfil das ações de jogo e local, adotamos a estatística descritiva, apresentando os valores de média e desvios padrão. Na análise inferencial, recorremos ao teste da função discriminante com o método de extração das variáveis Stepwise. Para comparar as ações do jogo estudadas por nível de rendimento das equipes (classificação final na tabela da competição), utilizamos o teste de ANOVA, do tipo One-way, com teste post hoc de Scheffé. As análises foram realizadas no pacote estatístico SPSS for Windows®, versão 18.0. Os resultados encontrados apontam o local do jogo e a posse de bola como variáveis que melhor explicam as vitórias nos jogos analisados. Em relação às comparações feitas com as ações do jogo, por nível de rendimento, encontramos diferenças significativas para a posse de bola no resultado de vitória, derrota e empate. Relativamente ao passe certo e passe errado, houve diferença significativa apenas para o resultado empate.The present study identified among these variables, which best explain the outcome of the football game. Were analyzed 380 games of the 2011 Brazilian championship. Data were obtained indirectly by a company called Footstats which is specializing in statistical analysis of football. The study variables were home field advantage, ball control, pass right ball and go wrong ball, all of them defined by the interest of the author. For the presentation of the shares in the football game and home field advantage was used descriptive statistics, showing the mean and standard deviations. In inferential analysis, we used to test the discriminant function with the extraction method of stepwise variable. To compare the actions of the game by income level of the teams (final ranking in the competition), was used ANOVA, One-way type, with Scheffé post hoc test. Analyses were performed in SPSS for Windows ® version 18.0. The results show the location of the game and ball possession as variables that best explain the victories in the games analyzed. As for the comparisons made about the actions of the game, we found significant differences between the income levels of the teams in ball possession. The teams that have better performance showing higher percentage in comparison with the other results of win, lose and draw. Given this we can infer that there was an influence of these indications mentioned above in relation to the sample
Evolution of patient-reported outcome measures, 1, 2, and 5 years after surgery for subaxial cervical spine fractures, a nation-wide registry study
No full textBACKGROUND CONTEXT: A longer duration of patient follow up arguably provides more reli-able data on the long-term effects of a treatment. However, the collection of long-term follow up data is resource demanding and often complicated by missing data and patients being lost to follow up. In surgical fixation for cervical spine fractures, data are lacking on the evolution of patient reported out -come measures (PROMs) beyond 1-year of follow up. We hypothesized that the PROMs would remain stable beyond the 1-year postoperative follow up mark, regardless of the surgical approach. PURPOSE: To assess the trends in the evolution of patient-reported outcome measures (PROMs) at 1, 2-, and 5-years following surgery in patients with traumatic cervical spine injuries. STUDY DESIGN: Nation-wide observational study on prospectively collected data. PATIENT SAMPLE: Individuals treated for subaxial cervical spine fractures with anterior, poste-rior, or combined anteroposterior approaches, between 2006 and 2016 were identified in the Swed-ish Spine Registry (Swespine). OUTCOME MEASURES: PROMs consisting of EQ-5D-3Lindex and the Neck Disability Index (NDI) were considered. METHODS: PROMs data were available for 292 patients at 1 and 2 years postoperatively. Five-years PROMs data were available for 142 of these patients. A simultaneous within-group (longitu-dinal) and between group (approach-dependent) analysis was performed using mixed ANOVA. The predictive ability of 1-year PROMs was subsequently assessed using linear regression. RESULTS: Mixed ANOVA revealed that PROMs remained stable from 1-to 2-years as well as from 2-to 5-years postoperatively and were not significantly affected by the surgical approach (p<0.05). A strong correlation was found between 1-year and both 2-and 5-years PROMs (R>0.7; p<0.001). Linear regression confirmed the accuracy of 1-year PROMs in predicting both 2-and 5-years PROMs (p<0.001). CONCLUSION: PROMs remained stable beyond 1-year of follow up in patients treated with ante-rior, posterior, or combined anteroposterior surgeries for subaxial cervical spine fractures. The 1 -year PROMs were strong predictors of PROMs measured at 2, and 5 years. The 1-year PROMs were sufficient to assess the outcomes of subaxial cervical fixation irrespective of the surgical approach.& COPY; 2023 The Author(s). Published by Elsevier Inc.This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/
Conceptual and Empirical Challenges in the Study of Firm Growth
No full textWhen the first author reviewed the literature on small firm growth in the mid 1980’s for his disserta-tion work, he noted that surprisingly few studies had focused on that specific problem (Davidsson 1989a; 1989b). Today, this is no longer true. In recent years ever more comprehensive lists of studies have been compiled and reviewed. Storey (1994) compiled results from more than 25 studies. Delmar (1997) scrutinized the operationalizations of growth in 55 studies. The second author of the present manuscript recently reviewed and classified close to 70 studies for his dissertation work (Wiklund, 1998), while Ardishvili, Cardozo, Harmon & Vadakath (1998) included in their classification a full 105 published and unpublished studies focusing on new and/or small firm growth. \ud
However, rather than presenting a set of solid generalizations on the causes and effects of growth, these reviewers all tend to come up with relatively critical accounts. These criticisms concern both theoretical and methodological shortcomings. (Storey, 1994, p. 5; 125, Cooper, 1995, p. 120; Delmar (1997, pp. 205; 212; Wiklund, 1998, pp. 6-7; 19; Ardishvili et al, 1998, p. 1) \ud
In addition to the above evaluations of research specifically on growth, we also have the observation that longitudinal designs are generally lacking in entrepreneurship research (Cooper 1995, p. 112; Wik-lund 1998, p. 7). In the latest ‘State-of-the-Art’ volume, several authors mentioned the lack of longitu-dinal studies in entrepreneurship research as a major impediment (Aldrich & Baker, 1997, p. 389; Sex-ton, 1997, p. 407) \ud
As a result of the shortcomings pointed out by the critics, it is still true today that knowledge about what facilitates and hinders growth is still scattered and limited. The same is true for insights into the process of firm growth. Apparently, the large number of empirical studies has not given a very high yield of generalizable knowledge. This suggests that researchers who set out to contribute meaningfully to this line of empirical research have a number of challenges to deal with. On the basis of the criticism summarized above we would suggest that some of the more important challenges are the following:\ud
• to develop a satisfactory basic research design\ud
• to apply a well-founded conceptualization of growth, which in turn requires a well thought-out con-ceptualization of ‘the firm’\ud
• to adequately match this conceptualization with the purpose of the study, the theories used, and the operationalization of growth.\ud
\ud
In the remainder of this chapter we will elaborate our views on these challenges. In the next section we will argue that growth studies need to be longitudinal, and why this is so. We will then turn to the conceptualization of the firm and the unit of analysis in growth studies, which turns out to be a really difficult problem. After that we discuss theoretical perspectives and how these match with different conceptualizations of the firm. Finally, we turn to operationalization issues, i.e. the choice of growth indicators, specific ways to model growth trajectories, and the distinction between organic and acquired growth. Throughout, we also discuss how these issues relate to different purposes, i.e. whose knowl-edge interests the study aims to satisfy
Indonesia & mitos negeri macan Asia
No full textBuku ini merupakan sebuah pemikiran dari mahasiswa akan krisis yang terjadi di negara ini. Benarkah Indonesia sudah merdeka dan berdikari? Atau hanya berubah dari penjajahan senjata ke penjajahan sosial ekonomi? Melalui buku ini pembaca akan diajak untuk menilik lebih dalam mengenai isu-isu kesejahteraan sosial masyarakat yang masih perlu diperhatikan. Penulis membingkai setiap permasalahan dalam negeri dari berbagai macam sudut pandang. Lewat buku ini, penulis ingin memperlihatkan bahwa Indonesia sedang tidak baik-baik saja. Sehingga ketika pembaca menyentuh akhir kata dalam buku ini, timbul kesadaran untuk membuktikan bahwa julukan (Macan Asia) bagi Indonesia bukan sekadar mitos belaka. Buku ini merupakan karya pertama penulis, tentu masih terdapat banyak kelemahan. Oleh karena itu, penulis sangat terbuka untuk terusmenerus dilakukan perbaikan dan penyempurnaan. Penulis berharap kepada berbagai pihak untuk memberikan saran, masukan, dan kritik konstruktif untuk perbaikan dan penyempurnaan di masa-masa yang akan datang
The investment behaviour of Taiwanese in mainland China
No full textThis thesis studies the patterns of Taiwanese investment behaviour in China. It also analyzes the implications on current economic, cultural and political trends and appraises the determinants influencing the Taiwanese direct investment (TDI) in China. As an active force in the economic development of the world, China is attractive to enterprises and producers from all over the world. Despite the complicated political environments between China and Taiwan, the Taiwanese have been investing in China for years. The increasing TDI in China is because of Taiwan's own depressed economic, political and social conditions, as well as FDI incentives offered by the Chinese government. Ethnical and language issues, as well as guanxi, also play important roles in this whole business process. Besides the above motives, this study also points out that an important motive for TDI in China is that Taiwanese industries are based on a 'subcontracting system', a unique international production/distribution network in East Asia, seen especially in Chinese regions. The motives of FDI from Taiwan into China are very different from the motives of FDI based on oligopolistic enterprises. TDI in China tends to involve an entire Taiwanese 'industrial migration', instead of the movement of firms due to the Taiwanese subcontracting system. This thesis aims to contribute to the study of FDI on Taiwanese firms which have mainland based ventures. This thesis attempts to provide an overall picture of T D I in China by exploring the investment motives, industries, and locations over a set time span. This thesis examines the determinants of locational choices o n T D I in China based on a conditional ๒git model. Similar to Hou and Zhang's study (2001), my empirical results Find that there is strong evidence of structural change on the determinants of locational choices of T D I in China over time, especially for infrastructure and labour costs. The factors behind this structural change include China's WTO entry and cultural links supported by the FDI policy. The results also show that the technology transfer from TDI into China has been significant for my sample perio
