Housing affordability is the relationship between households’ income and housing expenditure. The public are very concerned about the high price of residential housing in Beijing, which is considered go beyond the income of average citizens. In order to fully understand the China’s real estate market, the paper first analyses the land policy, housing reform and housing finance, etc. Then this paper examine to what the extent the high housing price had led to low levels of housing affordability from 2000 until 2009 among Beijing urban households. The ratio analysis has been conducted to measure housing affordability. Meanwhile, we compute the housing-induced poverty, find maximum affordable housing prices for all the income classes, and suggest the housing assistance that should be provided to urban households in Beijing. Approximately, only 20% Beijing urban residents have purchase affordability for a standardized new residential housing, no matter which approach is used, strong statistical evidences reveal that there is an incessant large gap between residential housing prices and urban residents’ incomes in Beijing.

If communicating via a teleconference phone the desired transmitted signal (speech) needs to be crystal clear so that all participants experience a good communication ability. However, there are many environmental conditions that contaminates the signal with background noise, i.e sounds not of interest for communication purposes, which impedes the ability to communicate due to interfering sounds. Noise can be removed from the signal if it is known and so this work has evaluated different ways of estimating the characteristics of the background noise. Focus was put on using speech detection to define the noise, i.e. the non-speech part of the signal, but other methods not solely reliant on speech detection but rather on characteristics of the noisy speech signal were included. The implemented techniques were compared and evaluated to the current solution utilized by the teleconference phone in two ways, firstly for their speech detection ability and secondly for their ability to correctly estimate the noise characteristics. The evaluation process was based on simulations of the methods' performance in various noise conditions, ranging from harsh to mild environments. It was shown that the proposed method showed improvement over the existing solution, as implemented in this study, in terms of speech detection ability and for the noise estimate it showed improvement in certain conditions. It was also concluded that using the proposed method would enable two sources of noise estimation compared to the current single estimation source and it was suggested to investigate how utilizing two noise estimators could affect the performance.

<p>У докторату је предложен је нови модел за утврђивање деагрегационих<br />пропорција у top down методологији за хијерархијско прогнозирање.<br />Како би се утврдили показатељи рада новог приступа, извршена су<br />теоријска (симулациона студија) и емпиријска истраживања (студија<br />случаја) више ешалонског дистрибутивног ланца. Резултати показују да<br />нови приступ значајно превазилази стандардне моделе top down<br />методологије. Такође, у докторату је тестиран и утицај хијерархијских<br />прогноза на логистичке показатеље (просечне залихе и недостатак<br />залиха). Резултати показују да је нови модел остварио најмањи<br />недостатак залиха приликом примене у стратегијама управљања<br />залихама. Поред наведеног, у докторату је тестирано и комбиновање<br />различитих прогноза и истраживање утицаја особина временских серија<br />на прецизност прогнозирања модела за хијерархијско прогнозирање.</p> / <p>U doktoratu je predložen je novi model za utvrđivanje deagregacionih<br />proporcija u top down metodologiji za hijerarhijsko prognoziranje.<br />Kako bi se utvrdili pokazatelji rada novog pristupa, izvršena su<br />teorijska (simulaciona studija) i empirijska istraživanja (studija<br />slučaja) više ešalonskog distributivnog lanca. Rezultati pokazuju da<br />novi pristup značajno prevazilazi standardne modele top down<br />metodologije. Takođe, u doktoratu je testiran i uticaj hijerarhijskih<br />prognoza na logističke pokazatelje (prosečne zalihe i nedostatak<br />zaliha). Rezultati pokazuju da je novi model ostvario najmanji<br />nedostatak zaliha prilikom primene u strategijama upravljanja<br />zalihama. Pored navedenog, u doktoratu je testirano i kombinovanje<br />različitih prognoza i istraživanje uticaja osobina vremenskih serija<br />na preciznost prognoziranja modela za hijerarhijsko prognoziranje.</p> / <p>In this thesis, a new approach for determining disaggregating proportions in<br />the top down hierarchical forecasting methodology is proposed. In order to<br />estimate the accuracy of the proposed approach, the simulation and case<br />study are performed. Results demonstrate that the approach significantly<br />outperforms standard top down approaches. Also, in this reserach the impact<br />of hierarchical forecasts on logistics indicators (average stock and lack of<br />inventory) is researched. The results show that the new model achieved the<br />smallest lack of inventory in inventory management strategies. Likewise, in<br />this research, the ideas of combining the hierarchical forecasting models and<br />quantifying the influence of time series characteristics on the accuracy of<br />hierarchical forecasting models, are tested. The results are encouraging and<br />further researches are needed in order to reveal all possible benefits of<br />proposed ideas.</p>