Spelling suggestions: "subject:"mixed"" "subject:"fixed""
161 |
中國大陸固定資產投資活動研究賴文乾, Lai, Wen-Chian Unknown Date (has links)
由於中國大陸的經濟發展屬於投資主導型,固定資產投資的變動在中國大陸的國民經濟發展中扮演著舉足輕重的角色,歷次固定資產投資的過度膨脹,也引發了國民經濟體系嚴重的問題。因此,本論文針對固定資產投資規模、結構以及經濟效益的變動趨勢及特徵做研究分析,並探討其形成的機制及原因。
固定資產是指能長期發揮生產或服務社會的功能且保持其實物形態不變的設備,固定資產投資的規模、結構和經濟效益直接影響著未來的經濟成長、國民收入以及就業狀況,所以研究固定資產投資活動,對於了解經濟發展的模式有其重要性。
中國大陸的固定資產投資規模具有波動頻繁和波動幅度劇烈的特徵,但1981年之後,投資增長率和波動頻率都有下降的趨勢。至於各種經濟類型投資比重的變化趨勢上,從80年代開始,非全民所有制單位的投資比重即大幅上升,而且國家預算內資金佔固定資產投資資金來源的比重也逐漸在下降,自籌資金和其它投資成為固定資產投資的主要資金來源。
關於固定資產投資與通貨膨脹的關係,本論文中對1980-1998年統計資料進行迴歸分析的結果,並不能得出兩者有顯著相關的結論,所以投資膨脹未必是通貨膨脹的充份條件,僅能說是其中一項重要影響因素。
在固定資產投資結構方面,呈現出明顯的非均衡發展趨勢,不但物質生產部門與非物質部門間表現出不均衡的特徵,物質生產部門內各產業的投資結構同樣具有非均衡的特性。而且自從經濟改革以來,固定資產投資的地區結構不均衡現象有持續惡化的趨勢,從投資總量和增長速度來看,東部沿海地區都超過中西部地區,而且投資比重仍持續上升。
除了產業結構和地區結構分佈不均的問題外,固定資產投資尚面臨了外延化趨勢明顯、更新改造投資嚴重不足,以及結構中技術成份低落和大量重複建設、盲目投資等嚴重問題。
最後關於固定資產投資的經濟效益問題,表現固定資產建設效益的指標:建設週期以及固定資產交付使率,在1980年之前都呈現出較大的波動,1980年之後由於投資體制的改革以及提升效益成為經濟工作的重點,固定資產投資效益狀況有所改善,整體表現也逐漸趨於穩定。固定資產投資的整體經濟效益則大致呈現出與建設效益相同的變化趨勢。
儘管在經濟改革之後,固定資產投資效益已有所改善,但依然存在若干問題,其中主要的問題有下列三點:(1)投資效益分佈不均;(2)投資資金分散,未能形成規模經濟,重複建設嚴重,影響了資源的利用效率;(3)現有固定資產設備並未獲得充分利用。
中國大陸整個固定資產投資的演變發展,在改革之前呈現出高增長、差結構與低效益的狀況,改革之後由於政治經濟環境的穩定性有所提升,並且來自非經濟面的干擾因素減少,使得投資的增長速度和結構合理許多,投資效益也因而獲得提升,但不可忽視,中國大陸的固定資產投資依然維持著強大的膨脹動能,需要持續探化投資改革促使經濟結構更加成熟。
|
162 |
Fixering av Cross-beam på Fixed Caliper 22"Ohlsson, Johan January 2009 (has links)
<p>Denna rapport behandlar mitt examensarbete som genomfördes i samarbete med Haldex</p><p>Brake AB. Haldex Brake AB håller på och utvecklare en ny generation broms åt lastbilar.</p><p>Uppdraget bestod av tre delar. Att ta fram lösningsförslag som säkerhetsställer beläggjärnets</p><p>placering i förhållande ett beläggjärn så kallad Cross-beam. Att säkerställa att bultar monteras</p><p>med rätt åtdragningsmoment på 230Nm. Den sista tredjedelen av arbetet bestod i att</p><p>presentera lösningar som helt eller delvis eliminerar oljud, när olika komponenter med spel,</p><p>slår i delar i okhuset.</p><p>I projektet har flera olika principkonstruktioner tagits fram och genom Freddy Olsson</p><p>utvärderingsmallar har sedan en primärkonstruktion utarbetats fram.</p><p>I dem andra två resterande projektdelarna belyses lösningarna väldigt generellt av den</p><p>anledningen att det kräver specialkomponenter.</p>
|
163 |
Reagerar sjukskrivna för psykiska besvär annorlunda på en ersättningsförändring i sjukförsäkringen jämfört med övriga sjukskrivna? : En empirisk undersökning för perioden 1996-1999Koort, Anna, Zetterberg, Karin January 2006 (has links)
<p>Syftet med denna uppsats är att undersöka om de som är sjukskrivna med diagnosen psykisk sjukdom reagerar annorlunda vid ersättningsförändringen i sjukförsäkringen år 1998 jämfört med övriga sjukskrivna. I detta syfte har vi tillämpat två Fixed effects modeller på paneldata över en fyraårsperiod, 1996 till 1999, som innefattar Sveriges län. Som approximation på andelen med psykisk sjukdom bland de sjukskrivna har vi använt Apotekets statistik över konsumtionen av antidepressiva medel och sömn- och lugnande medel. Under förutsättning att läkemedelskonsumtion är en god approximation för andelen med psykisk sjukdom i länen. Får vi ett statistisk signifikant resultat som tyder på att andelen med psykisk sjukdom bland de sjukskrivna reagerar mindre positivt på ersättningsförändringen år 1998 jämfört med övriga sjukskrivna.</p>
|
164 |
Conditional tests of corporate governance theoriesChi, Jianxin 29 August 2005 (has links)
Agency theories suggest that governance matters more when agency conflicts are potentially more severe. However, empirical studies often do not control for the potential severity of agency conflicts. I show that the marginal benefit of governance varies with the free cash flow level, a proxy for the potential severity of agency conflicts. As the free cash flow level increases, higher governance quality becomes incrementally more value-enhancing, and lower governance quality becomes incrementally more value-destroying. This is consistent with the hypothesis that better governance helps resolve the agency conflicts in investment decisions when a firm has more free cash flows (Jensen, 1986). This study highlights the importance of controlling for the potential severity of agency conflicts in governance studies and provides an improved method to estimate the marginal benefit of a governance mechanism.
|
165 |
Human Capital and Economic Performance : Empirical evidence from Panel Data AnalysisDzansi, James Yao January 2005 (has links)
No description available.
|
166 |
Fault diagnosis of a Fixed Wing UAV Using Hardware and Analytical RedundancyAndersson, Michael January 2013 (has links)
In unmanned aerial systems an autopilot controls the vehicle without human interference. Modern autopilots use an inertial navigation system, GPS, magnetometers and barometers to estimate the orientation, position, and velocity of the aircraft. In order to make correct decisions the autopilot must rely on correct information from the sensors. Fault diagnosis can be used to detect possible faults in the technical system when they occur. One way to perform fault diagnosis is model based diagnosis, where observations of the system are compared with a mathematical model of the system. Model based diagnosis is a common technique in many technical applications since it does not require any additional hardware. Another way to perform fault diagnosis is hardware diagnosis, which can be performed if there exists hardware redundancy, i.e. a set of identical sensors measuring the same quantity in the system. The main contribution of this master thesis is a model based diagnosis system for a fixed wing UAV autopilot. The diagnosis system can detect faults in all sensors on the autopilot and isolate faults in vital sensors as the GPS, magnetometer, and barometers. This thesis also provides a hardware diagnosis system based on the redundancy obtained with three autopilots on a single airframe. The use of several autopilots introduces hardware redundancy in the system, since every autopilot has its own set of sensors. The hardware diagnosis system handles faults in the sensors and actuators on the autopilots with full isolability, but demands additional hardware in the UAV.
|
167 |
Anaerobic Digestion of Corn Ethanol Thin Stillage for Biogas Production in Batch and By Downflow Fixed Film ReactorWilkinson, Andrea 10 June 2011 (has links)
Anaerobic digestion (AD) of corn thin stillage (CTS) offers the potential to reduce corn grain ethanol production energy consumption. This thesis focuses on results collected from AD of CTS at mesophilic temperatures in batch and by down-flow fixed film reactor. Experiments conducted include a series of biochemical methane potential (BMP) assays that investigated the digestion of CTS as the sole carbon source at a variety of food-to- microorganism ratios with and without acclimated biomass, under co-digestion conditions and also with the addition of supplemental nutrients. Additional BMP assays were conducted which investigated the potential to reduce fresh water consumption by using of digested effluent for substrate dilution. Continuous studies employed two 28L down-flow stationary fixed film reactors to examine. Chemical oxygen demand and volatile solids removal efficiencies greater than 85% were achieved up to an organic loading rate of 7.4 g TCOD/L/d and hydraulic retention time of 5 days.
|
168 |
On Covering Points with Conics and Strips in the PlaneTiwari, Praveen 1985- 14 March 2013 (has links)
Geometric covering problems have always been of focus in computer scientific research. The generic geometric covering problem asks to cover a set S of n objects with another set of objects whose cardinality is minimum, in a geometric setting. Many versions of geometric cover have been studied in detail, one of which is line cover: Given a set of points in the plane, find the minimum number of lines to cover them. In Euclidean space Rm, this problem is known as Hyperplane Cover, where lines are replaced by affine hyperplanes bounded by dimension d. Line cover is NP-hard, so is its hyperplane analogue. Our thesis focuses on few extensions of hyperplane cover and line cover.
One of the techniques used to study NP-hard problems is Fixed Parameter Tractability (FPT), where, in addition to input size, a parameter k is provided for input instance. We ask to solve the problem with respect to k, such that the running time is a function in both n and k, strictly polynomial in n, while the exponential component is limited to k. In this thesis, we study FPT and parameterized complexity theory, the theory of classifying hard problems involving a parameter k.
We focus on two new geometric covering problems: covering a set of points in the plane with conics (conic cover) and covering a set of points with strips or fat lines of given width in the plane (fat line cover). A conic is a non-degenerate curve of degree two in the plane. A fat line is defined as a strip of finite width w. In this dissertation, we focus on the parameterized versions of these two problems, where, we are asked to cover the set of points with k conics or k fat lines. We use the existing techniques of FPT algorithms, kernelization and approximation algorithms to study these problems. We do a comprehensive study of these problems, starting with NP-hardness results to studying their parameterized hardness in terms of parameter k.
We show that conic cover is fixed parameter tractable, and give an algorithm of running time O∗ ((k/1.38)^4k), where, O∗ implies that the running time is some polynomial in input size. Utilizing special properties of a parabola, we are able to achieve a faster algorithm and show a running time of O∗ ((k/1.15)^3k).
For fat line cover, first we establish its NP-hardness, then we explore algorithmic possibilities with respect to parameterized complexity theory. We show W [1]-hardness of fat line cover with respect to the number of fat lines, by showing a parameterized reduction from the problem of stabbing axis-parallel squares in the plane. A parameterized reduction is an algorithm which transforms an instance of one parameterized problem into an instance of another parameterized problem using a FPT-algorithm. In addition, we show that some restricted versions of fat line cover are also W [1]-hard. Further, in this thesis, we explore a restricted version of fat line cover, where the set of points are integer coordinates and allow only axis-parallel lines to cover them. We show that the problem is still NP-hard. We also show that this version is fixed parameter tractable having a kernel size of O (k^2) and give a FPT-algorithm with a running time of O∗ (3^k). Finally, we conclude our study on this problem by giving an approximation algorithm for this version having a constant approximation ratio 2.
|
169 |
Anaerobic Digestion of Corn Ethanol Thin Stillage for Biogas Production in Batch and By Downflow Fixed Film ReactorWilkinson, Andrea 10 June 2011 (has links)
Anaerobic digestion (AD) of corn thin stillage (CTS) offers the potential to reduce corn grain ethanol production energy consumption. This thesis focuses on results collected from AD of CTS at mesophilic temperatures in batch and by down-flow fixed film reactor. Experiments conducted include a series of biochemical methane potential (BMP) assays that investigated the digestion of CTS as the sole carbon source at a variety of food-to- microorganism ratios with and without acclimated biomass, under co-digestion conditions and also with the addition of supplemental nutrients. Additional BMP assays were conducted which investigated the potential to reduce fresh water consumption by using of digested effluent for substrate dilution. Continuous studies employed two 28L down-flow stationary fixed film reactors to examine. Chemical oxygen demand and volatile solids removal efficiencies greater than 85% were achieved up to an organic loading rate of 7.4 g TCOD/L/d and hydraulic retention time of 5 days.
|
170 |
A Lefschetz fixed point formula for elliptic quasicomplexesWallenta, Daniel January 2013 (has links)
In a recent paper with N. Tarkhanov, the Lefschetz number for endomorphisms (modulo trace class operators) of sequences of trace class curvature was introduced. We show that this is a well defined, canonical extension of the classical Lefschetz number and establish the homotopy invariance of this number. Moreover, we apply the results to show that the Lefschetz fixed point formula holds for geometric quasiendomorphisms of elliptic quasicomplexes.
|
Page generated in 0.0335 seconds