116 research outputs found
QUALITY IN TERMS OF COST EFFICIENCY
The studies based on using selective research are one of the maininstruments in the strategy building process at the managing level of academic facilities and collecting the data in the most effective way possible is one of the main problems that this kind of studies can arise.A way of solving this problem could be collecting the necessary dataonline, which implies human and financial resources a lot reduced compared to the classical way. Based on selective research, conducted among students, it has been tested the quality of the data collected online, by comparing them to the ones collected by face-to-face interviews.The studies that use selective research, conducted in the academicenvironment, in student collectivities, alumni, future possible students, the employers that might need the university’s graduates etc., are quite suitable for using the online collecting method of the data, due to the characteristics of the analyzed collectivities
A hybrid model-based and memory-based short-term traffic prediction system
Short-term traffic forecasting capabilities on freeways and major arterials have received special attention in the past decade due primarily to their vital role in supporting various travelers\u27 trip decisions and traffic management functions. This research presents a hybrid model-based and memory-based methodology to improve freeway traffic prediction performance. The proposed methodology integrates both approaches to strengthen predictions under both recurrent and non-recurrent conditions. The model-based approach relies on a combination of static and dynamic neural network architectures to achieve optimal prediction performance under various input and traffic condition settings. Concurrently, the memory-based component is derived from the data archival system that encodes the commuters\u27 travel experience in the past. The outcomes of the two approaches are two prediction values for each query case. The two values are subsequently processed by a prediction query manager, which ultimately produces one final prediction value using an error-based decision algorithm. It was found that the hybrid approach produces speed estimates with smaller errors than if the two approaches employed separately. The proposed prediction approach could be used in deriving travel times more reliable as the Traffic Management Centers move towards implementing Advanced Traveler Information Systems (ATIS) applications
A stochastic mesoscopic cell-transmission model for operational analysis of large-scale transportation networks
The cell transmission model (CTM), developed by Daganzo in 1994 was not fully exploited as an operations model for analysis of large-scale traffic networks. Because of its macroscopic / mesoscopic features, CTM offers calibration and computational advantages over microscopic models. This study presents a series of enhancements to the original form of CTM. These enhancements show potential to increase the model’s accuracy and realism of traffic flow representation. For example, topological enhancements and modifications to the flow advancing equation are introduced to allow variable cell lengths and non-discrete movements of vehicles between cells. In addition, implementation of lane-changing behavioral logics and algorithmic enhancements to model vehicle flows at network junctions demonstrate potential in modeling realistic non-homogeneous traffic streams in CTM. A calibration exercise was conducted to account for randomness in driving behavior using vehicle trajectory data. This proves the models potential in modeling stochastic variations of real-life networks. A sample freeway network of I-10 corridor in Baton Rouge was used to evaluate and compare the performance of the improved version of CTM versus CORSIM. The simulation results showed comparable performance of both platforms in terms of link occupancy (density) and total network travel time and demonstrate the potential of employing CTM in traffic operations applications
Mathematical Model of the Three-Phase Induction Machine for the Study of Steady-State and Transient Duty Under Balanced and Unbalanced States
SHADOW ECONOMY AND FOREIGN DIRECT INVESTMENTS: AN EMPIRICAL ANALYSIS FOR THE CASE OF ROMANIA
Shadow economy (SE) represents a controversial phenomenon, present more or less in all economies, whose empirical estimates should be regarded with due reserve. The main goal of this paper is to analyze the nature of the relationship between Romanian shadow economy, expressed as % of the official GDP and the foreign direct investments (FDI) using two causality analysis methods, namely the Granger causality analysis method and the Toda-Yamamoto procedure, based on quarterly data, over the period 2000-2010. The paper will also try to particularize the implications of this relationship on the sustainable development of the Romanian economy. For that purpose we will use the shadow economy series estimated in a previous article using one of the monetary approaches, the currency demand approach, based on econometrical methodology of error correction models and co-integration. The quantitative demarche of shadow economy estimation is detailed in Alexandru (Davidescu) and Dobre (2013). The empirical results highlight a unidirectional short-run causality that runs only from foreign direct investments to the shadow economy. The impulse responses function indicates a short-run negative relationship between FDI and SE
E STUDIES AND RESEARCH TO IDENTIFY MAJOR OPPORTUNITIES AND PROBLEMS FACED BY THE ORGANIC ROMANIAN FARMERS
The oscilatory evolution of the number of operators registered in the field of organic agriculture during the latest years, as well as the general trend of organical breading and of increase in cultivated areas, were prerequisites for an exploratory research among manufacturers. The present studyis prezents a collection of information based on the depth controlled interview, aiming at identifying the main challenges and opportunities faced by the organic Romanian farmers. We had in mind a number of main objectives related to the economic environment, the market of organic products, the financial situation and the investment value, the certification process, etc. The result of the study highlighted the importance of the development of organic production, using appropriate technologies and management methods
THE ORGANIC EGG MARKET IN ROMANIA: FEATURES, PRICES AND TRENDS
The eco-egg is one of the most present organic products in Romanian stores. Although it has a high price, it is an alternative to conventional egg for many consumers. For a better understanding of the market, I conducted a research focused on two components: one to monitor the evolution of prices on the shelves and one to investigate among consumers, using in-depth interview method.In the first phase of the study resulted that the price of organic egg is much larger and it does not present a significant seasonal variation, as well as in the case of conventional eggs.In the second stage of the research I tried to identify the main reasons leading to the high prices of the organic products, as well as explaining the differences in the evolution of the price in the case of organic eggs compared to conventional ones. It was also identified a number of problems faced by chicken breeders in the Romanian organic system, some special features of the market as well as some trends in terms of market development for organic eggs
An empirical analysis using panel data gravity models and scenario forecast simulations for the Romanian exports in the context of COVID-19
The paper focuses on the trade performance of Romania, a representative country for the Central and Eastern European region,
strongly connected with its European partners in global value
chains and thus affected by any change in these countries’ relationships with the rest of the world in general and China in particular. Using panel data gravity models for the 2008-2019 period,
we find that Romania’s exports are significantly influenced by the
demand of its major trade partners in the EU, and imports from
China and the rest of the world. In addition, exports are vulnerable to the effectiveness of the government in relation to the
other countries, corruption control and cultural values such as collectivism. We also assess the capacity of Romanian exports to
regain their ascending trend displayed before the COVID-19 pandemic by using simulation forecasting scenarios based on the
shape of the economic recovery and the type of shock transmission across economies. We observe a sharp decrease in 2020 followed by an important recovery in 2021 in a V-shape scenario
and uniform transmission of the pandemic shock in the internal
demand and in the foreign trade, or followed by a very slow
recovery in 2021 (in a U-shape scenario and non-uniform transmission type in the two previously mentioned elements), especially when the global relation with rest of the world is included
Methodology to Predict the Time of Blockage (ToB) for Bicycle Sharing Systems.
As of 2018, Montreal’s bicycle-sharing system (BSS), BIXI Montreal, is managing about 6,200 bicycles and 540 stations from mid-April till mid-November. A major problem that arises in BSS’s is bicycle and/or dock availability. A more predictable system will help optimize bicycle-rebalancing and raise the customers’ satisfaction of the service which, eventually, will generate incentives for mode-shifting and reducing traffic congestion. In this thesis, we used the 2017 open-source data along with basic demographic information, provided by BIXI, to create a methodology that will improve rebalancing procedures and add adjustability to a BSS. Preliminary investigation of the data shows that bicycle/dock availabilities are critical during the AM peak hours - when most users utilize the system for commute. Arriving on time in the morning is a priority for most users and providing a convenient infrastructure service for this is believed to be essential for any growing city. At the station level, we examine arrivals and departures as well as capacity and inter-station distances. At the user level, we examine gender, age, language and trip duration. The developed methods will allow bicycle sharing systems to study the variation of the Time of Blockage (ToB) as the user profile changes. This is very useful when there is interest in geographical expansion of the system. The methods will also allow for real-time monitoring of the ToB instead of using pre-set dispatch times. This will definitely optimize bicycle rebalancing operations - maximizing convenience, availability and users’ satisfaction
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