<p>Due to the global warming of the atmosphere it is now time to decrease the consumption of energy. One of the most important consumer is the commercial building area and especialy the supermarket. After a survey of the total consumption and a division into unit process it is possible to find some measures to decrease the global consumption of energy (in the lighting, cooling/freezing and space heating processes).</p>

The typical residential building is located at the crossing of S. Centralgatan Street and Nedre Akargatan Street in the city of Gavle. It is a quadrangle building of six floors with a yard in the middle. There are 180 apartments of five types in total, and at the first floor there is a kindergarten. There is a District Heating in the building and heating recovery system ventilation which use heat exchanger to reheat. Several solutions are used for reducing the heat loss. In the first step, the heat loss  and heat  in  has  been  calculated. There  are  several parameters  that involve the heat loss and heat in of whole building, so each parameter in the energy balance equation is extracted and calculated. And then the Energy Balance Sheet has been built. Among the heat loss part, the transmission is 1237MWh,  the  hot  tap  water  is  332MWh,  the  mechanical  ventilation  is 1041MWh, the natural ventilation is 325.7MWh.In the part of heat in, the DH is 1265.7MWh, the heat pump is 793MWh, the solar radiation is 562MWh, the internal heating is 315MWh.Later in the second step, after analyzing data of heat loss part, the improvements will be focused on the transmission and hot tap water parts because the heat loss in those two parts occupy the most. At the end of final step, the solutions have been discussed to optimize the heating system. As conclusion, there are several suggested solutions. The total reduction of heat loss after adjustment is 163MWh, accounts 5.6% of originally heat loss. The  heat  loss  of  the  building  has  been  reduced  from  2935.7MWh  to 2772.7MWh.

Nowadays efficiency measures are more and more important because the price of the energy is increasing every year. Moreover, saving energy it is also important for decrease the environmental impact. Kastvallen is a hockey arena built in 1997 that cools the hockey rink with electric compressors. The changing rooms are heating by using district heating. Actually the total invoice of electricity is above the 800000 SEK. Meanwhile the district heating invoice reaches the 60000SEK. The aim of this project is reducing the amount of the electricity and heat invoice promoting smart energy improvements. The improvements proposals can be divided in three sections; energy savings of the changing rooms, efficiency increase of the compressors and dehumidifier energy savings. For heat the tap water and the changing room’s ventilation it is suggested to take profit from the heat released at the condenser and so reduce its heat load requirements. For this proposal two different configurations are studied. In order to increase the efficiency of the compressors the possibility of reducing the condenser temperature will be studied. Three proposals will be studied to carry out this commitment; Installing a condensing temperature control, installing a evaporate cooler and having a snow storage. Finally, one of the largest consumers of electricity in Kastvallen ice hockey rink is the dehumidifier. The current dehumidifier works with a desiccant wheel. The desiccant material extract the moisture from the processed air flow, after that the desiccant has to be reactivated with ‘fresh air’. This reactivation air needs to be heated 95ºC, so the waste air released after the reactivation of the desiccant is air at high temperature. The first proposal is preheat the reactivation air with the hot waste air in order to reduce the heating requirements, conducting this proposal the total money saved each year would be 41811 SEK with a Pay-back around 1 year. The second step is studied the possibility of heating the air with district heating, taking into account that district heating is three times cheaper than electricity, conducting this proposal the total money saved each year would be 45629 SEK with a Pay-back around 1 year. The last proposal is to combine preheating and heating with district heating, conducting this proposal the total money saved each year would be 61553 SEK with a Pay-back around 1.6 years. All the previous energy improvements proposals are studied with empirical and analytical methods and using the knowledge gained during the previous years of studies. The study concludes that the best proposal for the dehumidifier is combine the preheating and heating with district heating. In addition of the money saved, this measure allows to save 2.71 Tm of CO2 each year. For the refrigeration cycle, the study concludes that installing a controlled temperature control is the best option if the price of that is lower than 334726 SEK. If not the best option is heating the rooms and the ventilation with the condenser of the refrigeration cycle. These measures could reduce between 8% and 20% of the total energy invoice plus a considerable reduction of CO2 emissions. Evaporative cooling and snow storage would be studying after with the data of the first year of the condensing temperature control; if it is installed.

Comments and Discussion : Minoru Sawai

This dissertation addresses three issues in international macroeconomics. The first chapter examines optimal portfolio decisions in a monetary open economy DSGE model. In a complete market environment, Engel and Matsumoto (2005) find that sticky price can generate equity home bias. However, their result is sensitive to the structure of the financial market. In an incomplete market environment, we find “super home bias” in the equilibrium equity portfolio, which casts doubt on the ability of sticky price in describing the observed equity portfolios. We further show that introducing sticky wages helps to match the data. The second chapter analyzes the welfare impact of financial integration in a standard monetary open-economy model. Financial integration may have negative effects on welfare if integration occurs in the presence of nominal price rigidities and constraints on the efficient use of monetary policy. The reason is that financial integration leads to excessive terms of trade volatilities. From a policy perspective, the model implies that developing economies that are experiencing financial integration may attempt to alleviate the welfare cost of integration by stabilizing the exchange rate. This prediction is consistent with the widespread reluctance to following freely floating exchange rates among these economies. On the other hand, for advanced economies that have the ability to operate efficient inflation targeting monetary policies, financial integration is always beneficial. Thus, the model accounts for the observed acceleration in cross-border asset trade among advanced economies in the early 1990s as it was mainly the industrial countries that switched to an inflation targeting regime at the time. The third chapter uses an open-economy neoclassical growth model to explain the saving and investment behavior of the U.S. and a group of other OECD countries. We find that while the model explains investment quite well, it tends to overpredict U.S saving and underpredict saving in the rest of the world. We show that the closed-economy version of the model also predicts saving accurately but that is only because it imposes equality between saving and investment. In effect, the model explains investment not saving behavior.

Due to the global warming of the atmosphere it is now time to decrease the consumption of energy. One of the most important consumer is the commercial building area and especialy the supermarket. After a survey of the total consumption and a division into unit process it is possible to find some measures to decrease the global consumption of energy (in the lighting, cooling/freezing and space heating processes).

Today, more and more embedded hardware devices are reaching the market and consumers with a demand for smaller and better devices than yesterday. Increasing the performance of a device decreases the operating time since more power is consumed, still, decreasing the size of the device also decreases operating time as the battery size decreases.To allow the performance to increase and the size of the device to decrease, the designer must nd techniques allowing the hardware to consume less power during normal usage of a device than during the peak usage.In this thesis an implementation of an ARM based microprocessor system is presented and used for measuring and evaluation of the power consumption possibilities of the system.

The fact that saving is one of the main factors to economic growth is unquestionable. Accumulated saving can be consider as the sources of capital stock to which play a crucial role in creating investment, production, and employment. And all these activities eventually enhance the economic growth. Therefore the main objective of this paper, ―The relationship between domestic saving and economic growth and convergence hypothesis: case study of Thailand‖, was to investigate the causality relationship between the domestic saving and economic growth of Thailand. This paper will analyze whether the direction of causality go from domestic saving to economic growth, or vice versa. Granger causality test were conducted by using time series annual data from 1960 to 2010, and the empirical result suggests that the direct of causality go from economic growth to domestic saving only. Aiming to grow its economy, Thailand had had development plans which used both saving and direct investment to stimulate economy. This paper examine whether the convergence hypothesis does hold in Thailand. This part would check whether or not Thailand is in the process of convergence, catching up, lagging behind, loose catching up, loose lagging behind or divergence over time compared with other developed countries. This test was conducted in pairwise between Thailand-Singapore, Thailand-United States, Thailand-United Kingdom, deployed data from 1970 to 2010, and the Augmented Dickey–Fuller (ADF) Test. The regression results demonstrate that convergence hypothesis does not hold in Thailand. Finally, the result of Granger Causality report that economic growth rate does matter lead to growth rate of domestic savings in Thailand only. Thus, in order to learn the effect of gross domestic saving per capita growth rate can help narrow the different of GDP between two countries concerned, this paper will examine the correlation of two variables, deployed the OSL methods to investigate the correlation between gross domestic saving growth rate and the different of GDP per capita between Thailand and Singapore. This test also examine whether saving does help support convergence hypothesis for Thailand or not. The test results shows that domestic saving growth rate does not help narrowing the range of different of income of Thailand and Singapore which mean that domestic saving growth rate does not support the convergence hypothesis in Thailand.

Wireless sensor networks offer easy implementation, flexibility and mobility of hand held devices. Sensors consist of an internal power source, which is the great limitation for the life time and the usage of sensor networks. To increase the life time, sensors should stay in energy saving sleep mode as long as possible, because in sleep mode the radio is either shut down or working with less energy. Better energy handling is implemented in different power saving mechanism of common Medium Access Control protocols, which are evaluated and analyzed and further extensions and ideas to improve the energy efficiency are presented. Slotted PSM is simulated with the NS2 and compared to the WLAN 802.11 PSM technology and the results show that energy efficiency and power consumption are much better implemented and life time increases with the use of Slotted PSM.

Web browsing via Wi-Fi wireless access networks has become a basic function on a variety of consumer mobile electronic devices, such as smart phones, PDAs, and the Apple iPad. It has been found that in terms of energy consumption, wireless communications/networking plays an important role in mobile devices. Since the power-saving mode (PSM) of the IEEE 802.11 a/b/g standard is not tailored for the HTTP protocol, we propose a novel power saving scheme that exploits the characteristics of web applications. After sending HTTP requests, the proposed power saving scheme updates the estimated value of RTT based on the information contained in the TCP timestamp header field. Next, the proposed scheme adjusts the value of the listening period based on the estimated value of RTT. When all TCP connections have been closed, the wireless network card could enter the deep-sleeping mode. In this case, the value of the listening period could be larger than one second, since the user is reading the webpage and is unlikely to send another HTTP request within one second. The usage of the deep-sleeping mode can significantly reduce the power consumption of mobile devices.