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Iulian-Cornel Lolea and Lucian Constantin Vilcu

Abstract

This paper aims to identify if regime-switching GARCH models perform better than singlestate GARCH models for the Romanian stock market. There will be used two approaches: in-sample and out-of-sample. All estimations are going to be made for the BET Index, which is the most relevant index from the selected market. The results will be ranked based on statistical loss functions for each of the two considered approaches. These rankings should ensure an accurate comparison for models’ performance and they succeeded to return about the same results as in the relevant literature. Hence, for the in-sample evaluation there was no model which performs best for all loss-functions, but one can notice that for the out-of-sample evaluation the regime-switching models performed better especially on short-term (1-day observation period). All of these results were used further to improve some risk management strategies based on VaR, for which the volatility could be estimated through regimeswitching GARCH models, than considering historical volatility.

Open access

Lucian-Eugen Bolboacă, Emanuel Ştefan Baltag, Lucian Fasolă-Mătăsaru and Constantin Ion

ABSTRACT

The Yellow-browed Warbler is a species of the Sylviidae family that breeds in Asia and winters in South East Asia and western Europe. In northern and north-western Europe it is considered one of the most numerous nocturnal migratory species from Siberia. In the southern and eastern part of the continent there are fewer observations of the presence of the species in passage or in winter. On 29 September 2013, during a ringing session in the southern part of the Danube Delta (Romania), we captured a juvenile individual of the Yellow-browed Warbler. This is the first record of the species in Romania.

Open access

Traian Vasile Constantin, Victor Lucian Mădan, Maria-Magdalena Constantin, Silviu-Horia Morariu and Bogdan Braticevici

Abstract

Prostate cancer is, after lung cancer, the most common malignant disease diagnosed in the male population. The introduction into the practice used during the 80’s and 90’s of the determination of serum Prostate-Specific Antigen (PSA) levels, as a component of screening for prostate cancer, was a turning point in the medical practice. Due to this enzyme produced exclusively by the prostate gland, the prostate cancer detection rate (in curative, intracapsular stages) improved significantly. Serum PSA is a better predictive factor for prostate cancer (PC) than digital rectal examination or transrectal prostatic ultrasound.

Open access

Emanuel Ștefan Baltag, Viorel Pocora, Constantin Ion and Lucian Sfîcă

Abstract

Long-legged Buzzard (Buteo rufinus) is a medium sized bird of prey which is known as a breeding species for Romania. In the last years it started to become a common wintering presence in the south-eastern part of Romania (Dobrogea) but it was also recorded in the more northern areas (Moldova) during the cold season. Its presence in Moldova, during the winter period, was recorded in large river valleys, with agricultural lands or grasslands and with trees or timber poles, which are used for perching. Long-legged Buzzard is a new presence for Moldavian winter seasons and it could be observed only in warm periods of winter, when the daily mean temperature is above 0°C. The wintering places are maintained not only for all winter period, but also for the next years. This behaviour could be explained by its territorial fidelity, which was recorded also in other European buzzard species during the winter period.

Open access

Carmelia Mariana Dragomir, Daniel Eduard Constantin, Mirela Voiculescu and Lucian Puiu Georgescu Georgescu

Abstract

One way of monitoring the atmospheric pollution is to estimate anthropogenic emissions. This paper presents a study of PM10 emissions in a city SE of Romania (Braila) for the period 2009-2012. PM10 emissions decrease from 304.75 t in 2009 to 78.01 t in 2012. Using data from the Environmental Protection Agency Braila and the METI-LIS dispersion model, four maps were produced in order to estimate the spatial distribution of PM10 emission in each year. Results of dispersion models show that the air quality can change abruptly between points at few meters away. Expectedly, PM10 emissions increase towards the centre of the city centre, are generally higher in the vicinity of busy streets and roads.

Open access

Mirela Danubianu, Dragos Mircea Danubianu, Cristian Teodorescu and Lucian Constantin

Abstract

Energy and environment are top priorities for the EU’s Europe 2020 Strategy. Both fields imply complex approaches and consistent investment. The paper presents an alternative to large investments to improve the efficiencies of existing (outdated) power installations: namely the use of data-mining techniques for analysing existing operational data. Data-mining is based upon exhaustive analysis of operational records, inferring high-value information by simply processing records with advanced mathematical / statistical tools. Results can be: assessment of the consistency of measurements, identification of new hardware needed for improving the quality of data, deducing the most efficient level for operation (internal benchmarking), correlation of consumptions with power/ heat production, of technical parameters with environmental impact, scheduling the optimal maintenance time, fuel stock optimization, simulating scenarios for equipment operation, anticipating periods of maximal stress of equipment, identification of medium and long term trends, planning and decision support for new investment, etc. The paper presents a data mining process carried out at the TERMICA - Suceava power plant. The analysis calls for a multidisciplinary approach, a complex team (experts in power&heat production, mechanics, environmental protection, economists, and last but not least IT experts) and can be carried out with lower expenses than an investment in new equipment. Involvement of top management of the company is essential, being the driving force and motivation source for the data-mining team. The approach presented is self learning as once established, the data-mining analytical, modelling and simulation procedures and associated parameter databases can adjust themselves by absorbing and processing new relevant information and can be used on a long term basis for monitoring the performance of the installation, certifying the soundness of managerial measures taken and suggesting further adjustments