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2014年 2 月9 日
Radio network planning process and methods for WCDMA
Abstract
This paper describes the system dimensioning and the radio network planning methodology for a third generation WCDMA system. The applicability of each method is demonstrated using examples of likely system scenarios. The challenges of
modeling the multiservice environment are described and the implications to the system performance simulations are introduced.
Keywords: Telecommunication network planning, Mobile radio- communication, Code division multiple access, Wide band transmission, Multiple service network, Dimensioning, Simulator, Static model, Dynamic model, Cellular network.
Resume(?)
Contents
I.Introduction
II. Initial planning, system dimensioning
III. Detailed planning process
IV. Example dimensioning case and verification of
dimensioning with static simulations
V. Comparison of a static to a dynamic network simulator
VI. Conclusion
INTRODUCTION
As the launch of third generation technology approaches, operators are forming strategies for the deployment of their networks. These strategies must be supported by realistic business plans both in terms of
future service demand estimates and the requirement for investment in network infrastructure. Evaluating the requirement for network infrastructure can be achieved using system dimensioning tools capable of assessing both the radio access and the core network components.
Having found an attractive business opportunity, system deployment must be preceded by careful network planning. The network planning tool must be capable of accurately modeling the system behaviour when loaded with the expected traffic profile. The third generation cellular systems will offer services well beyond the capabilities of today's networks. The traffic profile, as well as the radio access technology itself form the two most significant challenges when dimensioning and planning a WCDMA based third generation system. The traffic profile describes the mixture of services being used by the population of users. There are also specific system functionalities which must be modelled including fast power control and soft handover. In order to accurately predict the radio coverage the system eatures associated with WCDMA must be taken into account in the network modeling process. Especially the channel characterization, and interference control mechanisms in the case of any CDMA system must be considered. In WCDMA network multiple services co-exist. Different services (voice, data) have different processing gains, Eb/N0 performance and thus different receiver SNR requirements. In addition to those the WCDMA coverage depends on the load characterization, hand over parameterization, and power control effects. In current second generation systems' coverage planning processes the base station sensitivity is constant and the coverage threshold is the same for each base station. In the case of WCDMA the coverage threshold is dependent on the number of users and used bit rates in all cells, thus it
is cell and service specific.
The WCDMA planning process can be divided into three phases: initial planning (dimensioning), detailed radio network planning and network operation and optimization. Each of these phases requires additional support functions like propagation measurements, Key Performance Indicator definitions etc. In a cellular system where all the air interface connections operate on the same carrier the number of simultaneous users is directly influencing on the receivers' noise floors. Therefore, in the case of VMTS the planning phases cannot be separated into coverage and capacity planning. In the case of the post second-generation systems data services start to play an important role. The variety of services requires the whole planning process to overcome a set of modifications. One of the modifications is related to the quality of service (QoS) requirements. So far it has been adequate to specify the speech coverage and blocking probability only. Also more and more one has to consider the indoor and in-car coverage probabilities. In the case of UMTS the problem is slightly more multidimensional. For each service the QoS targets have to be set and naturally also met. In practice this means that the tightest requirement shall determine the site density. In addition to the coverage probability the packet data QoS criteria are related to the acceptable delays and throughput. Estimation of the delays in the planning phase requires good knowledge of the user behaviour and understanding in the functions of packet scheduler.
Common features between second and third generation coverage prediction also exist. In all the systems both of the links have to be analyzed. In current systems the links tend to be in balance whereas in the case of third generation one of the links can be higher loaded than the other, and thus either one of the links could be limiting the cell capacity or coverage. The propagation calculation is basically the same for all standards, with the exception that different propagation models could be used. Another common feature is the interference analysis. In the case of WCDMA this is needed for the loading and sensitivity analysis, in the case of TDMA/FDMA it is essential for frequency allocation. In order to fully utilize the WCDMA capabilities, a thorough understanding of the WCDMA air interface is needed from the physical layer to the network modeling, planning and performance optimization.
In this paper the pre-operational phase of the WCDMA planning process, as depicted in Figure 1in detail, is discussed. Section II is concentrating on the initial planning issues. The WCDMA link budget is introduced and it is demonstrated how different services and their QoS requirements impact on the site density estimate. In Section III a static radio network simulator is introduced. The methodology required in the coverage and capacity estimation for WCDMA is described for both uplink and downlink. Topic of Section IV is to demonstrate the accuracy of dimensioning: an example area is dimensioned and the average site distance is determined. The dimensioning result is compared with the outcome of a static network simulation. In Section V the analysis methods of the static simulator are verified. The verification was performed with a dynamic system simulator. The paper is concluded in Section VI.
I.INITIAL PLANNING, SYSTEM DIMENSIONING
Initial planning (i.e. system dimensioning) provides the first and most rapid evaluation of the network element count as well as the associated capacity of those elements. This includes both the radio access network as well as the core network. This paper focuses upon the radio access part solely. The target of the initial planning phase is to estimate the required site density and site configurations for the area of interest. Initial planning activities include radio link budget (RLB) and coverage analysis, capacity estimation, and finally, estimation for the amount of base station hardware and sites, radio network controllers (RNC), equipment at different interfaces, and core network elements. The service distribution, traffic density, traffic growth estimates and QoS requirements are essential already in the initial planning phase. In the initial planning phase the quality is taken into account in terms of blocking and coverage probability. RLB calculation is done for each service, and the tightest requirement shall determine the maximum allowed isotropic path loss.
A.WCDMA specific items in the radio link budget
In this section the WCDMA uplink and downlink budgets are discussed. To estimate the maximum range of a cell a RLB calculation is needed. In the RLB the antenna gains, cable losses, diversity gains, fading margins, diversity gains etc.
are taken into account. The output of the RLB calculation is the maximum allowed propagation path loss which in return determines the cell range and thus the amount of sites needed. There are a few WCDMA specific items in the link budget if one compares to the current TDMA based radio access system like GSM. These include interference degradation margin, fast fading margin, transmit power increase and soft handover gain.
The interference degradation margin is a function of the cell loading. The more loading is allowed in the system, the larger interference margin is needed in uplink, and the smaller is the coverage area. The uplink loading can be derived as follows, for simplicity the derivation is performed with service activity v = 1.
To find out the required uplink transmitted and received signal power for a mobile station MSk connected to a particular base station BSn, the basic CDMA Eb/N0 equation is used. The usual, slightly theoretical, assumption is that Ioth, the interference received from the MSs connected to the other cells is directly proportional (proportionality constant i) to Iown, the interference received from the MSs connected to the same BSn as the desired MS. Assume that the MSk uses bit rate Rk, its Eb/N0 requirement is Pk and the CDMA modulation bandwidth is W. Then the received power of the k-th mobile, Pk, at the base station it is connected to, must be at least such that
公式(1)
k=l ..... K
where Kn is the number of MSs connected to BSn, N= NoW = NfkToW is the noise power in the case of an empty cell, Nf is the receiver noise figure, k is the Boltzmann constant and T0 is the absolute temperature.
The inequalities in (1) are slightly optimistic because it is assumed that there is no interference from the own signal. In reality this is not exactly true in multipath propagation conditions. Equation (1) is however still chosen to avoid taking
multipath interference into account twice. I.e., the Eb/N0 requirements determined from link level simulations are presented so that N0 means only noise and multipath interference is visible in higher Eb/N0 requirement to a certain BER performance. Solving the inequalities as equalities means solving for the minimum required received power (sensitivity), Pk:
公式(2)
If the Equations in (2) are summed over the mobile stations connected to BSn then
公式
公式(3)
since/ow, = ~ Pk' If loading is defined as k
公式(4)
this loading definition can be enhanced to include gain and service activity, v:
公式(5)
In [ 12] the uplink loading is estimated using equation
公式(6)
where m is the number of services used. The difference between Equations (5) and (6) are due to the fact that (6) does not include sectorisation gain and that
in the derivation starting from Equation (1) the denominator is Iown-Pk+
iIow +N rather than Iown+ iIown +N, which is only the case when Pk <<
Iown"
The downlink dimensioning is following the same logic as the uplink. For a
selected cell range the total base station transmit power ought to be estimated.
In this estimation the soft handover connections must be included. If the
power is exceeded either the cell range ought to be limited, or number of
users in a cell has to be reduced. For downlink the loading (ηDL) is
estimated based on
公式（7）
where LPmi is the link loss from the serving BSm to MSi, LPni is the link
loss from another BSn, to MSi, Pi is the transmit Eb/N0 requirement for the
MSi, including the SHO combining gain and the average power raise caused
by fast power control, N is the number of base stations, I is the number of
connections in a sector andαi is the orthogonality factor depending on
multipath conditions (α= 1: fully orthogonal).
公式：The term ~" defines the iDL. n =l,n~:m LPn i Direct output of the downlink RLB is the single link power required by a user at the cell edge. The total base station power estimation must take into account multiple communication links with average (LPmi) distance from the serving base station. Furthermore, the multicell environment with orthogonalities a i should be included in the modeling. More on the downlink loading and transmit power estimations can be found in [13]. In the RLB calculation in uplink direction the limiting factor is the mobile station transmit power, in downlink direction the limit is the total base station transmit power. When balancing the uplink and downlink service areas both links
must be considered.
Fast fading margin or power control headroom is another COMA specific item in the RLB. Some margin is needed in the mobile station transmission power for maintaining adequate closed loop fast power control in unfortunate propagation conditions like the cell edge. This is applicable especially for pedestrian users where the Eb/N0 to be maintained is more sensitive to the closed loop power control. The power control headroom has been studied more in [6] and [7].Another impact of the fast power control is the transmit power increase. In the case of a slowly moving mobile station the power control is able to follow the fading channel and the average transmitted power increases. In own cell this is needed to provide adequate quality for the connection and does not cause any harm, since increased transmit power is compensated by the fading channel. For neighbouring cells however this means additional interference. The transmit power increase (TxPowerlnc) is used to reduce the reuse efficiency according to Equation (9). In Equation (4) i should be replaced with term TxPowerlnc×i in case the mobile station transmit power increase is significant.
Soft handover gain is discussed already in [3]. Handovers-soft or hard-provide gain against shadow fading by reducing the required fading margin.Due to the fact that the slow fading is partly uncorrelated between cells, and by making handovers the mobile can select a better communication link. Furthermore, soft handover (macro diversity) gives an additional gain against fast fading by reducing the required Eb/N0 relative to a single radio link. The amount of gain is a function of mobile speed, diversity combining algorithm used in the receiver and channel delay profile. More about the SHO gain can be found in Section II C. Receiver sensitivity estimation
In the link budget the BS receiver noise density is estimating the noise level over one WCDMA —carrier. The required receiver SNR contains the processing gain and the loss due to the loading. The loading used is the total loading due to different services on the carrier in question. The required signal power (S) depends on the SNR requirement, receiver noise figure and bandwidth.
公式（10）
Where
公式（11）
公式（12）
where Nf is the receiver noise figure, Κis Boltzmann constant, To is the absolute temperature and ηis the loading. In some cases the basic noise/interference level is further corrected with the man made noise term.
A.Shadowing margin and soft hand over gain estimation
The next step is to estimate the maximum cell range and cell coverage area in different environments/regions. The RLB is estimating the maximum allowed isotropic path loss, from that value a slow fading margin, related to the coverage probability, has to be subtracted. When estimating the coverage probability the propagation model exponent and the standard deviation for the log-normal fading must be set. If the indoor case is considered the indoor loss is from 15dB to 18dB
and the standard deviation for log-normal fading margin calculation is set to 10-12dB.In the case of outdoor coverage typical standard deviation value is 7 to 8dB. Typical propagation constants range from 2.5 to 4. Traditionally the area coverage probability used in the RLB is for single cell case [1]. The required probability is 90 % to 95 % and typically this leads to 7-8dB fading margin, depending on the propagation constant and standard deviation of the log-normal fading. The Equation (13) estimates the area coverage probability for single cell case: 公式（13）
Pr is the received level at cell edge, n is the propagation constant, x0 is the average signal strength threshold andσis the standard deviation of the field strength.
In real WCDMA cellular networks the coverage areas of cells overlap and the mobile station is able to connect to more than just one serving cell. If more than one cell can be detected the location probability increases and is higher than determined for a single isolated cell. Analysis performed in [2] indicates that if the area location probability is reduced from 96% to 90% the number of base stations is reduced by 38 %,This number indicates that the concept of multiserver location probability should be carefully considered. In reality the signals from two base stations are not completely uncorrelated, and thus the soft handover gain is slightly less than estimated in [2]. In [3] the theory of the multiserver case with correlated signals is introduced:
公式（14）
where P
out is the outage at the cell edge, γ
SHO
is the fading margin in the case
of soft handover, σis the standard deviation of the field strength and for 50 % correlation a = b = 1/21/2. With the theory presented for example in [1] this probability at the cell edge can be converted to the area probability. In the WCDMA link budget the SHO gain is needed. The gain consists of two parts: combining gain against fast fading and gain against slow fading. The gain against slow fading is dominating and it is specified as:
公式（15）
If we assume 95% area probability, n = 3.5 and the standard deviation is 7dB the gain will be 7.3dB-4dB=3.3dB. If the standard deviation is larger and the probability requirement higher the gain will be more.
B.Cell range and cell coverage area estimation
Once the maximum allowed propagation loss in a cell is known, it is easy to apply any known propagation model for the cell range estimation. The propagation model should be chosen so that it optimum describes the propagation conditions in the area. The restrictions of the model are related to the distance from the base station, the base station effective antenna height, the mobile antenna height and the frequency. One typical example for macro cellular environment is Okumura-Hata. Equation (16) presents an example Okumura-Hata path loss model for an urban macro cell with base station antenna height of 25m, mobile antenna height of 1.5m and carrier frequency of 1950 MHz [4].
公式(16)
After choosing the cell range the coverage area can be calculated. The coverage area for one cell in hexagonal configuration can be estimated with:
公式(17)
TABLE I. -Example of a WCDMA RLB.
Exemple d'un bilan de liaison radio WCDMA.
Where S is the coverage area, r is the maximum cell range and K is a constant, depending on the network topology. The number of sectors is typically from 1 to 3.In the case of WCDMA reasonable values are up to 6 sectors. In the case of 6 sectors the estimation of the cell coverage area becomes problematic,since a six-sectored site does not necessary resemble a hexagon. A proposal for the cell area calculation at this stage is that the equation for the omni case is used also in the case of 6 sectors and the larger area is due to a higher antenna gain. The more sectors are used the more careful soft handover overhead has to be analysed to provide an accurate estimate. In
Table II some of the K-values are listed.
TABLE II. --K-values for the site area calculation. Valeurs du param~tre K pour le calcul d'une zone de couverture autour d'un site
C.Capacity and coverage analysis in the initial planning phase
Once the site coverage area is known the site configurations in terms of channel elements, sectors and carriers, and site density (cell range) has to be selected so that the supported traffic density can fulfil the requirements. An example dimensioning case can be seen in Section IV. The WCDMA RLB is slightly more complex than the TDMA one. The cell range depends on the number of simultaneous users (number of channels/users in terms of interference margin, see Equation (6)). Thus the coverage and capacity are connected and already in the very beginning the operator should have knowledge and vision of the subscriber distribution and growth since it has a direct impact on the coverage. Finding the correct configuration for the network so that the traffic requirements are met and the network cost minimised is not a simple task. The number of carriers, number of sectors, loading, number of users and the cell range all have an impact on the result.
III. DETAILED PLANNING PROCESS
A.Introduction to a static radio network planning simulator
In this study the simulator first introduced in [9] was used. It is of static nature and needs as inputs a digital map, the network layout and the traffic distribution in form of a discrete user map. Each of the users can have different terminal speed and uses a different service (bit rate, activity factor, which both can be different ’for uplink and downlink). Therefore each mobile station gets assigned an individual Eb/N0 requirement imported from link level simulations. The simulator itself consists of basically three parts-initialisation, combined uplink and downlink analysis and post processing phase. Following the initialisation part, round after round in the main part of the tool, both the uplink and downlink for all mobile stations are analysed and after the iterations have fulfilled certain convergence criteria, in the final step, the results of the uplink and downlink analyses are post processed for various graphical and numerical outputs. On top of these results, for selected areas (which also can consist of the whole network) area coverage analyses for UL and OL dedicated channel as well as for common channels (common pilot CPICH, broadcast control channel 8CCH, forward access and paging channel FACH and PCH on the P-CCPCH and S-CCPCH) can be performed. In case a second carder is present in the network area, either used by the same operator or by another operator adjacent channel interference (ACI ) can be taken into account. Only in case the second carrier is assigned to the same operator, load can be
shared according different strategies between the carriers (IF-HO).
B. Initialisation Phase
In the global initialisation phase the network configuration is read in from parameter files for base stations, mobile stations and the network area. Some system parameters are set and propagation calculations are performed. In the following step, requirements coming from the link level simulations are assigned to base stations and mobile stations. After some initialisation tasks for the iterative analysis-setting default transmit power sand network performance -the actual simulation can start.
https://www.doczj.com/doc/382305989.html,bined uplink and downlink analysis
C1. Uplink iteration step
The target in the uplink iteration is to allocate the mobile stations' transmit powers so that the (interference+noise)-levels and thus the base station sensitivity values converge. The average transmit powers of the mobile stations to each base station are estimated so that they fulfil the base stations Eb/N0 requirements. The average mobile stations'transmit powers are based on the sensitivity level of the base station, service (data rate) and speed of the mobile station and the link losses to the base stations. They are corrected by taking into account the
activity factor, the soft handover gains and average power raise due to fast transmit power control. The impact of the uplink loading on the base station sensitivity (noise rise) is taken into account by adjusting it with (l-η). ηcan be defined by Equation (5).
After the average transmit powers of the mobiles have been estimated they are compared to the maximum value allowed and mobiles exceeding this limit are trying IF-HO if allowed or are put to outage. Now the interference analysis can be performed again and the new loading and base station sensitivities are calculated until their changes are smaller than specified thresholds. Also in case the uplink loading of a cell exceeds specified limits, mobile stations are moved to another carrier if allowed (IF-HO). Otherwise they are put to outage.
C2. Downlink iteration step
Similarly to the uplink the goal of the downlink iteration is to assign the base station transmit powers for each link (including SHO connections) a mobile station is having until all mobile stations receive their signal with the required carrier-to-interference-ratio, C/I, defined by Equation (18) 公式(18)
is the received Eb/N0 requirement of the MS depending on where EbNo
MS
terminal speed and service. The actual received (C/I)
of MS m is calculated
m
using MRC according Equation (19) by summing the C/I values of all links k, k = 1... K mobile station m is having.
公式(19)
where P
is the total transmit power of the base station to which link k is k
is the link loss from the cell k to the mobile station m, αestablished, Lp
k m
k is the cell specific orthogonality factor, P
is the power allocated to the link
km
is the other cell interference from base station k to mobile station m, I
oth,
m
and Nm is the background and receiver noise of MS m.
The initial transmit powers are adjusted iteratively according the difference between the achieved and the targeted C/I value until convergence is achieved. The process requires iteration, since the C/I at each mobile station is dependent on all the powers allocated to the other mobile stations and it is not known a priori whether a link can be established or not. In case either certain link power limits or the total transmit power of a base station is exceeded mobile stations are performing IF-HO if allowed or taken out randomly from the network.
In a further step for each mobile station it is checked whether the received Ec/Io value is above a user defined threshold so that the mobile station can
reliably measure the base station and synchronise to it. Also here if the threshold given is exceeded, the mobile station tries IF-HO or is put to outage. A flow chart for the detailed iteration steps can be seen from Figure 3.
C3. Adjacent channel interference calculations
The adjacent channel interference influence due to the two possible carriers - either from own network or from a competitive operator's network in the same area-is taken into account by filtering this interference with a channel separation dependent filter. In both directions UL and DL the adjacent carrier filtering is implemented as a two-fold process. In OL, one filter for the mobile stations has been implemented indicating its out of band radiation (acpFilterUL). This filter is used to indicate how much power the mobile station is leaking into the other carders receiving band (Adjacent Channel Leakage Ratio, ACZLR ) For the base station in the uplink another filter (aciFilterUL) has been implemented. This filter is indicating the selectivity of the base station's receiver in multicarrier situation, i.e. how big portion of the adjacent channel power is
received by the base station as adjacent channel interference power (Adjacent Channel Protection, ACP). Also this filter setting depends on the carrier separation. The adjacent channel interference situation in UL is depicted in Figure 4. In the simulations these two filters are combined to a single filter by Equation (20):
公式(20)
Adjacent channel interference (I
) is taken into account when calculating
ACI
the UL load according to Equation (21).
公式（21）
Also in the downlink similar type of filtering is introduced as in the uplink. One filter for the base stations has been implemented indicating the out of band radiation of the base station (acp Filter DL). This filter is used to indicate how much power the base station is leaking into the other carriers receiving band (ACLR). The filter setting depends on the separation between the carriers. For the mobile station another filter has been implemented (aci Filter DL). This filter is indicating the selectivity of the mobile station's receiver in multicarrier situation, i.e. how much of the adjacent channel interference power is received by the mobile station (ACP). Also this filter setting depends on the carrier separation. The adjacent channel interference situation in DL is depicted in Figure 5. In the simulations these two filters are combined to a single filter by Equation (22):
公式（22）
Adjacent channel interference (I
) in DL is taken into account when
ACI
calculating the C/I of a single link a MS is having according to Equation (23).
公式（23）
is interference from where variables are as defined after Equation (19), I
oth
other cells on same carrier and I
is adjacent channel interference.
ACI
D. Predicting the network coverage
In all estimations of area coverage probability (UL, DL，DCH, CPICH, BCH, FACH, PCH) it is assumed that the interference situation is stable. This means that a certain traffic distribution has been assumed and the detailed UL and DE iteration has been run. A test mobile is then run through all pixel of the interesting area and all other MSs which could be served are contributing to the interference. The test mobile is not influencing on the interference situation, therefore the other to own cell interference ratio will not change and also the total transmit power of the serving BSs are constant.
UL DCH coverage
In UL direction now it can be estimated whether or not this additional mobile station using a certain bit rate and having a certain Go/No requirement could get the service in the chosen geographical location. This means, if the maximum allowed transmit power of the test MS is enough to fulfil the Go/No requirement at the BS receiver. The needed transmit power for the MS is calculated with Equation (24) and compared to the maximum allowed.
公式（24）
Area coverage probability finally is defined as the proportion of the chosen area where the additional MS really gets the wanted service under that stable interference situation. The weakness in this approach is that in reality an additional mobile station would change the interference situation, for example some other mobiles could go to outage but in the case of low bit rate services this effect can be neglected.
DL DCH coverage
In downlink direction the coverage probability calculation is based on the transmit power limits per radio link. The main focus is to check pixel-by-pixel, whether or not there is enough transmit power per link from base stations in the active set, if there would be a MS in the pixel, using a given service (bit rate) and having a given speed. Also here it is assumed that the total transmit powers of BSs do not change from what was left after UL/DL iteration, i.e. it could be assumed that the influence of the test MS is replaced by the closest original MS. In iteration however there may or may not have been a MS in the pixel. The coverage probability then again is defined as the amount of pixels from the whole area where the service was possible.
CPICH coverage
In radio network planning the CPICH transmit power should be set as
small as possible but ensuring that the best cell and neighbour cells can be measured and synchronised and the CPICH can be sufficiently used as the phase reference for all other DL physical channels. Typically this means that 5%-10% of the total BS power is used for CPICH. For each pixel in the chosen area the Ec/Io in that pixel is calculated according Equation (25).
公式（25）
where P
CPICH
is the CPICH power of the best server , Lp is the link loss to the
best server, P
i,
TX is the total transmit power of BSi, Lp
i
is the link loss to
BSi, I
ACI
is adjacent channel interference, No is the thermal noise of the default MS and numBSs is the number of base stations in the network. The achieved Ec/Io is then compared to a user given threshold and the CPICH coverage defined as the ratio of pixels where the threshold is exceeded compared to all pixels. The weakness of this modeling for the CPICH Ec/Io coverage is that it is done only for the best server. In an operating network however, all neighbour cells must also be measured and therefore all neighbour cells' CPICH Ec/Io should be analysed, too. This could be overcome however by e.g. adding a threshold to the required CPICH Ec/Io. Descriptions of other static simulators can be found for example in [18, 19].
IV. EXAMPLE DIMENSIONING CASE AND
VERIFICATION OF DIMENSIONING WITH
STATIC SIMULATIONS
This section is containing an example use case for the initial planning phase in case of a green field macrocellularr operator. In this example case only one network evolution phase is considered, in the real radio network planning case the traffic growth should be more carefully considered. In this work three cases have been analysed. First case is 8 kbps speech only, mobile station speeds 3 (50% of MSs) and 120 km/h (50% of MSs). Second case is dimensioning speech and circuit switched data (64kbps), speech mobiles moving 50 km/h, data terminals 3 km/h. The last Case is 144 kbps data only, terminals moving with 20 km/h. More details related to the case can be found in [14]. The study consisted of two parts. In the first part the operator's macrocellular network is dimensioned, i.e. the cell range is estimated with given input parameters. This study is based on the assumption that the traffic and the QoS information are available from the operator. In the second phase the network is planned for the estimated site distance (1.5*R) and the WCDMA analysis is performed for the radio network. As depicted in Figure 1 this use case is concentrating on the first half of the radio network planning process: the network dimensioning, network configuration definition and coverage/capacity planning.
In the first phase the dimensioning task is to generate certain traffic and QoS requirements for the above mentioned three cases and to dimension the cases accordingly. The radio network was dimensioned for an urban area of 13×13km2. The propagation model used was Okumura-Hata with an area correction factor of 0 dB. The traffic and QoS requirements for all the three cases are in Table III.
In the dimensioning process both the capacity and the coverage have to be considered. The cell range is determined not only by the RLB, but also on the capacity requirements. From the selected cell range the coverage area for the site can be estimated by Equation (17). Once the site coverage area is known the supported traffic density can be estimated. The selected site density must be such that the traffic density requirement and the coverage requirement in terms of coverage probability are met. In the following table the dimensioning results are collected. In the example case the cell range has been solely based on the uplink results. In uplink direction the target loading as specified by Equation (6) is limiting the number of channel elements per cell. As it can be seen already in the dimensioning results, the base station transmit power is actually limiting in all of the cases. In order to meet the capacity requirements either cell range, number of sectors or number of carriers should be changed. In this case only one carrier was used.
in the second phase of the work the dimensioning results in terms of number of cells and the cell range were used in the corresponding static simulator runs. The items with bold font in Table III and Table IV were used as inputs for the simulation. The site distance used in the static simulator has been estimated with D=1.5*R where R is the cell range obtained from the RLB in dimensioning. In this study the network scenario was based on a regular grid, and the network area consisted only of urban area type. The static simulator
described in Section III was used in this study. The Eb/No requirements and the traffic distribution used in the simulation were the same as were used during dimensioning. In the dimensioning phase only the antenna gain is used. In the simulations the antenna radiation pattern is also required and an antenna with 65°horizontal beam width was selected. The 65°antenna was selected because it is widely used already in 2G networks with three sectored configurations. Furthermore, according to [11] the 65 °provides the optimum performance for the used network configuration. In all the simulations the antenna gain was always 17 dBi. The soft handover addition window was set to -6 dB. In Figure 6 there is an example of the network scenario. The system features used in the simulations are from [10] and the ITU vehicular A channel [5] has been assumed for the channel delay profile.
According to the simulations in the speech case the dimensioning is too pessimistic for the uplink capacity. Based on the simulations the network could support 72 speech users versus the 60 proposed by dimensioning. The main difference is because of the interference statistics. The other to own cell interference ratio has relative large standard deviation (0.27, minimum value only 0.11) and thus there are cells which can carry more traffic than Equation (6) is proposing. With the help of the results in Table 5 it can be concluded that current dimensioning is correctly limiting the downlink capacity. According to the simulations with 65 °antenna the down-link should serve 46 users, the dimensioning is proposing 40.The simulated coverage probability is slightly higher than the requirement, and thus the site distance in reality could be slightly increased.
In the mixed traffic case the uplink dimensioning result was proposing 42 channel elements for speech users and 6 for data users to meet the traffic requirement. The UL simulation result is slightly different from the dimensioning result. The reason for this is partly that it is very difficult to control the simulation run so that the ratio of the data users and the speech users would be exactly as required. The initial requirement was that the data users are 17% of the total users. After the static simulator run the percentage was 16 %. In the case of UL there are in average 37 speech users instead of 42, but on the contrary there are 8 data users instead of 6. Therefore one can claim that the uplink dimensioning result is well in line with the simulation results. The power amplifier dimensioning for the DL (based on [13]) shows a clear downlink limitation. The uplink 48 users cannot be served in downlink direction with the assigned 20 W maximum base statio transmit power. When the number of users in the dimensioning was reduced to 27 speech and 6 data users the dimensioning estimates the total YX power of 17W including 10% common channel overhead. Values used for the power calculation were
55 % and peak to average ratio for Lp mi of 4dB. The downlink is
limiting also according to the network simulations. According to the simulation downlink analysis the network can support 25speech users and roughly 564 kbps data users simultaneously, the base station total transmit power being 19W to 20W depending on the selected scenario. In the mixed traffic case dimensioning of the base station total transmit power follows extremely well the simulations. In terms of coverage probability the dimensioning is slightly pessimistic. According to the simulations the data coverage probability is always better than the required 70%. Since the data service is limiting the cell range the speech coverage probability is always better than the required 95 %.
In the data case the dimensioning was proposing 855.6/144 = 5.94 simultaneous users (assuming 10 % soft capacity, and iDL = 55 %). This result is very close to the simulated case, but also in this case the uplink dimensioning is slightly pessimistic. In the downlink dimensioning with iDL = 55%, orthogonality 50% and 4dB peak to average ratio the BS transmit power for the 5 users is roughly 19W, including common channels (10% overhead) and 40% soft handover probability. A similar number is also achieved with the static simulations. In the data case the coverage probability is up to 8% higher than required. The difference in decibels of coverage probability of 80 % and 88 % is 2 to 3dB, depending on the exact parameter values that have been used in the estimations, see [1]. In coverage limited case this has an impact on the required number of sites. All simulation results are collected in Table V.
In Figure 7 there is an example of the dominance and coverage analysis
外文出处： 《Exploiting Software How to Break Code》By Greg Hoglund, Gary McGraw Publisher : Addison Wesley Pub Date : February 17, 2004 ISBN : 0-201-78695-8 译文标题： JDBC接口技术 译文： JDBC是一种可用于执行SQL语句的JavaAPI（ApplicationProgrammingInterface应用程序设计接口）。它由一些Java语言编写的类和界面组成。JDBC为数据库应用开发人员、数据库前台工具开发人员提供了一种标准的应用程序设计接口，使开发人员可以用纯Java语言编写完整的数据库应用程序。 一、ODBC到JDBC的发展历程 说到JDBC，很容易让人联想到另一个十分熟悉的字眼“ODBC”。它们之间有没有联系呢？如果有，那么它们之间又是怎样的关系呢？ ODBC是OpenDatabaseConnectivity的英文简写。它是一种用来在相关或不相关的数据库管理系统（DBMS）中存取数据的，用C语言实现的，标准应用程序数据接口。通过ODBCAPI，应用程序可以存取保存在多种不同数据库管理系统（DBMS）中的数据，而不论每个DBMS使用了何种数据存储格式和编程接口。 1．ODBC的结构模型 ODBC的结构包括四个主要部分：应用程序接口、驱动器管理器、数据库驱动器和数据源。应用程序接口：屏蔽不同的ODBC数据库驱动器之间函数调用的差别，为用户提供统一的SQL编程接口。 驱动器管理器：为应用程序装载数据库驱动器。 数据库驱动器：实现ODBC的函数调用，提供对特定数据源的SQL请求。如果需要，数据库驱动器将修改应用程序的请求，使得请求符合相关的DBMS所支持的文法。 数据源：由用户想要存取的数据以及与它相关的操作系统、DBMS和用于访问DBMS的网络平台组成。 虽然ODBC驱动器管理器的主要目的是加载数据库驱动器，以便ODBC函数调用，但是数据库驱动器本身也执行ODBC函数调用，并与数据库相互配合。因此当应用系统发出调用与数据源进行连接时，数据库驱动器能管理通信协议。当建立起与数据源的连接时，数据库驱动器便能处理应用系统向DBMS发出的请求，对分析或发自数据源的设计进行必要的翻译，并将结果返回给应用系统。 2．JDBC的诞生 自从Java语言于1995年5月正式公布以来，Java风靡全球。出现大量的用java语言编写的程序，其中也包括数据库应用程序。由于没有一个Java语言的API，编程人员不得不在Java程序中加入C语言的ODBC函数调用。这就使很多Java的优秀特性无法充分发挥，比如平台无关性、面向对象特性等。随着越来越多的编程人员对Java语言的日益喜爱，越来越多的公司在Java程序开发上投入的精力日益增加，对java语言接口的访问数据库的API 的要求越来越强烈。也由于ODBC的有其不足之处，比如它并不容易使用，没有面向对象的特性等等，SUN公司决定开发一Java语言为接口的数据库应用程序开发接口。在JDK1．x 版本中，JDBC只是一个可选部件，到了JDK1．1公布时，SQL类包（也就是JDBCAPI）
毕业设计（论文）外文文献翻译 文献、资料中文题目：软件开发概念和设计方法文献、资料英文题目： 文献、资料来源： 文献、资料发表（出版）日期： 院（部）： 专业： 班级： 姓名： 学号： 指导教师： 翻译日期： 2017.02.14
外文资料原文 Software Development Concepts and Design Methodologies During the 1960s, ma inframes and higher level programming languages were applied to man y problems including human resource s yste ms,reservation s yste ms, and manufacturing s yste ms. Computers and software were seen as the cure all for man y bu siness issues were some times applied blindly. S yste ms sometimes failed to solve the problem for which the y were designed for man y reasons including: ?Inability to sufficiently understand complex problems ?Not sufficiently taking into account end-u ser needs, the organizational environ ment, and performance tradeoffs ?Inability to accurately estimate development time and operational costs ?Lack of framework for consistent and regular customer communications At this time, the concept of structured programming, top-down design, stepwise refinement，and modularity e merged. Structured programming is still the most dominant approach to software engineering and is still evo lving. These failures led to the concept of "software engineering" based upon the idea that an engineering-like discipl ine could be applied to software design and develop ment. Software design is a process where the software designer applies techniques and principles to produce a conceptual model that de scribes and defines a solution to a problem. In the beginning, this des ign process has not been well structured and the model does not alwa ys accurately represent the problem of software development. However,design methodologies have been evolving to accommo date changes in technolog y coupled with our increased understanding of development processes. Whereas early desig n methods addressed specific aspects of the
附录1：外文资料翻译 A1.1外文资料题目 26.22 接地故障电路开关 我们目前为止报道的接地方法通常是充分的, 但更加进一步的安全措施在某些情况下是必要的。假设例如, 有人将他的手指伸进灯口（如Fig.26.45示）。虽然金属封入物安全地接地, 但那人仍将受到痛苦的震动。或假设1个120V 的电炉掉入游泳池。发热设备和联络装置将导致电流流入在水池中的危害，即使电路的外壳被安全地接地，现在已经发展为当这样的事件发生时，设备的电源将被切断。如果接地电流超过5mA ，接地开关将在5 ms 内跳掉，这些装置怎么运行的？ 如Fig.26.46所示，一台小变流器缠绕上导线 ，第二步是要连接到可能触发开合120 V 线的一台敏感电子探测器。 在正常情况下流过导体的电流W I 与中性点上的电流N I 准切的相等，因此流经核心的净潮流(N W I I -)是零。 结果，在核心没有产生电流，导致的电压F E 为零，并且开关CB 没有动作。 假设如果某人接触了一个终端(图Fig.26.45示)，故障电流F I 将直接地从载电线漏到地面，这是可能发生的。如果绝缘材料在马达和它的地面封入物之间断开，故障电流也会被产生。在以下任何情况下，流经CT 的孔的净潮流等于F I 或L I ，不再是零。电流被产生，并且产生了可以控制CB 开关的电压F E 。 由于5 mA 不平衡状态只必须被检测出，变压器的核心一定是非常有渗透性的在低通量密度。 Supermalloy 是最为常用的，因为它有相对渗透性典型地70000在通量密度仅4mT 。 26.23 t I 2是导体迅速发热的因素 它有时发生于导体短期内电流远大于正常值的情况下，R I 2损失非常大并且导体的温度可以在数秒内上升几百度。例如，当发生严重短路时，在保险丝或开关作用之前，会有很大的电流流过导体和电缆。 此外，热量没有时间被消散到周围，因此导体的温度非常迅速地增加。 在这些情况下什么是温度上升？ 假设导体有大量m ，电阻R 和热量热容量c 。 而且，假设电流是I ，并且那它流动在t 少于15秒期间。 在导体上引起的热 Rt I Q 2= 从Eq.3.17，在功率一定的情况下我们可以计算导体上升的温度差：
通信工程专业毕业设计题目 本文是关于通信工程专业毕业设计题目，仅供参考，希望对您有所帮助，感谢阅读。 第一类：通信工程设计1、通信网工程设计 2、程控室工程设计 3、传输室工程设计第二类：通信论文4、光城域网研究与组网 5、光波分复用技术的研究与分析 6、光同步数字体系的研究与分析7、论述移动通信的应用及发展 8、铁通XX 分公司宽带业务现状与发展 9、铁通XX分公司发展策略 10、提速铁路专用通信业务及发展 11、自拟与本职工作密切相关的通信工程专业课题第一类：通信工程设计题目要求《通信网设计》一、设计要求：1、作某一范围长途干线网设计； 2、绘出新设计通信网图并作相应阐述。二、主要内容：1、对通信网种类及构成要素作概括性阐述；2、拟定长途网业务节点数量及选用相应设备；3、对新设计通信网的信道构成特点、网型、保护方式等作相应阐述。《程控交换工程设计》一.设计要求:1.对原有设备情况的调查,收集各种资料 2.根据调查结果设计交换网图3.根据交换网图提出中继方式,其中包括信令方式,接口方式及传输方式等内容4.画出工程所需各部分图纸5.写出设计规范书及设计说明书二.完成图纸名称:1.交换网图 2.中继方式 3.设备平面布置图 4.总配线架,数字配线架端子分配图 5.电缆径路图 6.电源系统图7.工程数量表《传输室工程设计》一、设计要求：1、结合本单位条件或者处自拟条件作传输室施工设计，规模不限； 2、采用光纤传输设备或者数字微波设备及相关附属设备（如中配架、数配架、引入架、试验架等）；3、对各项设计作重点说明。二、主要内容：1、传输室设备平面布置图； 2、通信网图； 3、室内信道直线径路图； 4、中配架运用及分配图； 5、布线计划图改工程数量表。第二类：通信论文题目要求1、根据所选题目进行现场调研及收集资料；2、根据题目说明论文主要包括哪些部分；3、对每一部分作详细论述； 4、论文应包括论点、论据、论证过程及结论； 5、所涉及的数据、图表要准确； 6、论述过程中要有自己独创的观点；
外文翻译 专业机械设计制造及其自动化学生姓名刘链柱 班级机制111 学号1110101102 指导教师葛友华
外文资料名称： Design and performance evaluation of vacuum cleaners using cyclone technology 外文资料出处：Korean J. Chem. Eng., 23(6), (用外文写) 925-930 (2006) 附件： 1.外文资料翻译译文 2.外文原文
应用旋风技术真空吸尘器的设计和性能介绍 吉尔泰金，洪城铱昌，宰瑾李， 刘链柱译 摘要：旋风型分离器技术用于真空吸尘器 - 轴向进流旋风和切向进气道流旋风有效地收集粉尘和降低压力降已被实验研究。优化设计等因素作为集尘效率，压降，并切成尺寸被粒度对应于分级收集的50％的效率进行了研究。颗粒切成大小降低入口面积，体直径，减小涡取景器直径的旋风。切向入口的双流量气旋具有良好的性能考虑的350毫米汞柱的低压降和为1.5μm的质量中位直径在1米3的流量的截止尺寸。一使用切向入口的双流量旋风吸尘器示出了势是一种有效的方法，用于收集在家庭中产生的粉尘。 摘要及关键词：吸尘器; 粉尘; 旋风分离器 引言 我们这个时代的很大一部分都花在了房子，工作场所，或其他建筑，因此，室内空间应该是既舒适情绪和卫生。但室内空气中含有超过室外空气因气密性的二次污染物，毒物，食品气味。这是通过使用产生在建筑中的新材料和设备。真空吸尘器为代表的家电去除有害物质从地板到地毯所用的商用真空吸尘器房子由纸过滤，预过滤器和排气过滤器通过洁净的空气排放到大气中。虽然真空吸尘器是方便在使用中，吸入压力下降说唱空转成比例地清洗的时间，以及纸过滤器也应定期更换，由于压力下降，气味和细菌通过纸过滤器内的残留粉尘。 图1示出了大气气溶胶的粒度分布通常是双峰形，在粗颗粒（>2.0微米）模式为主要的外部来源，如风吹尘，海盐喷雾，火山，从工厂直接排放和车辆废气排放，以及那些在细颗粒模式包括燃烧或光化学反应。表1显示模式，典型的大气航空的直径和质量浓度溶胶被许多研究者测量。精细模式在0.18?0.36 在5.7到25微米尺寸范围微米尺寸范围。质量浓度为2?205微克，可直接在大气气溶胶和 3.85至36.3μg/m3柴油气溶胶。
中文翻译 STC89C52处理芯片 电气工程的研究和解决方案中心（ceers） 艾哈迈德为吉.波特 首要性能： 与MCS-51单片机产物兼容、8K字节在系统可编程视频存储器、1000次擦拭周期，全静态操作：0Hz~33Hz、三级加密程序存储器，32个可编程I/O接口线、三个16位定时器（计数器），八个中断源、低功能耗空闲和掉电模式、掉电后间断可唤醒，看门狗定时器、双数值指针，掉电标示符。 关键词：单片机，UART串行通道，掉电标示符等 前言 可以说，二十世纪跨越了三个“点”的时代，即电气时代，电子时代和现已进入的电脑时代。不过，这种电脑，通常指的是个人计算机，简称PC机。还有就是把智能赋予各种机械的单片机（亦称微控制器）。顾名思义，这种计算机的最小系统只用了一片集成电路，即可进行简单的运算可控制。因为它体积小，通常都是藏在被控机械的内部里面。它在整个装置中，起着有如人类头脑的作用，他出了毛病，整个装置就会瘫痪。现在，单片机的种类和适用领域已经十分广泛，如智能仪表、实施工控、通讯设备、导航系统、家用电器等。各种产品一旦用上了单片机，就你能起到产品升级换代的功效，常在产品名称前冠以形容词——“智能型”，如智能洗衣机等。接下来就是关于国产STC89C52单片机的一些基本参数。 功能特性描述: STC89C52单片机是一种低功耗、高性能CMOS8位微控制器，具有8K在系统可编程视频播放存贮器使用高密度非易失性存储器技术制造，与工业80C51 产物指令和引脚完全兼容。片上反射速度允许程序存储器在系统可编程，也适用于常规的程序编写器。在其单芯片上，拥有灵敏小巧的八位中央处理器和在线系统可编程反射，这些使用上STC89C52微控制器为众多嵌入式的控制应用系统提供高度矫捷的、更加有用的解决方案。STC89C52微控制器具有以下的标准功效：8K字节的反射速度，256字节的随机存取储存器，32位I/O串口线，看门狗定时器，2个数值指针，三个16 为定时器、计数器，一个6向量2级间断结构，片内晶振及钟表电路。另外，STC89C52可降至0HZ静态逻辑操作，支持两种软件可选择节电模式、间断继续工作。空闲模式下，CPU停止工作，允许RAM、定时器/计数器、串口、间断继续工作。掉电保护体式格局下，RAM内容被生成，振动器被冻结，单片机一切的工作停止，直到下一个间断或者硬件复位为止。8位微型控制器8K字节在系统中可编程FlashSTC89C52.。
信息与通信工程专业毕业论文 选题 卷积编码和维特比译码的 FPGA 实现 CVSD 音频编译码算法研究与 FPGA 实现 DQPSK 调制解调技术研究及 FPGA 仿真实现 基于FPGA 的高斯白噪声发生器设计与实现 无线通信系统选择分集技术研究 MIMO 系统空时分组编码的性能研究 基于量子烟花算法的认知无线电频谱分配技术研究 基于量子混沌神经网络的鲁棒多用户检测器 论文写作叩叩舞衣衣期酒吧期玖叁 船载AIS 通信系统调制器的设计与实现 基于FPGA 的QAM 调制器设计与实现 基于多载波通信的信道化技术研究 简易无线通信信号分析与测量装置 DFDTD 时域有限差分matlab 仿真 超宽带多径信道下 Chirp-rate 调制性能研究 超宽带无线传感器网络中低复杂度测距算法研究 基于低轨道编队飞行皮卫星群的空间网络设计与仿真 Lin ux 环境下无线传感器网络分簇路由算法的仿真研究 高速无线局域网 MAC 协议仿真研究 无线紫外光多址通信关键技术研究 认知无线电网络的频谱分配算法1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21.
基于软件无线电的多制式通信信号产生器设计与实现 开关电源EMI 滤波器的设计 反激式电源传导噪声模态分离技术的研究 核电磁脉冲源辐射的数值仿真 基于MATLAB 的扩频通信系统及同步性能仿真 一种多频带缝隙天线的设计 MSK 调制解调器及同步性能的仿真分析 跳频频率合成器的设计 OFDM 系统子载波间干扰性能分析 复合序列扩频通信系统同步方法的研究 基于DDS+ PLL 的频率源设计 基于训练序列的 OFDM 系统同步技术的研究 正交频分复用通信系统设计及性能研究 MIMO_OFDM 技术研究及其性能比较 基于蓝牙的单片机无线通信研究 物联网智能温室控制系统中远程信息无线传输的研究 物联网智能温室控制系统中温湿度光照采集无线传输的研究 基于WiFi 的单片机无线通信研究 FSK 调制的无线数字传输系统编码技术设计与实现 直扩系统中窄带干扰抑制技术的研究 卷积码的编译码设计及单片机实现 频域均衡技术的研究及 MATLAB 仿真 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43.
I / 11 本科毕业设计外文翻译 <2018届） 论文题目基于WEB 的J2EE 的信息系统的方法研究 作者姓名[单击此处输入姓名] 指导教师[单击此处输入姓名] 学科(专业 > 所在学院计算机科学与技术学院 提交日期[时间 ]
基于WEB的J2EE的信息系统的方法研究 摘要：本文介绍基于工程的Java开发框架背后的概念，并介绍它如何用于IT 工程开发。因为有许多相同设计和开发工作在不同的方式下重复，而且并不总是符合最佳实践，所以许多开发框架建立了。我们已经定义了共同关注的问题和应用模式，代表有效解决办法的工具。开发框架提供：<1）从用户界面到数据集成的应用程序开发堆栈；<2）一个架构，基本环境及他们的相关技术，这些技术用来使用其他一些框架。架构定义了一个开发方法，其目的是协助客户开发工程。 关键词：J2EE 框架WEB开发 一、引言 软件工具包用来进行复杂的空间动态系统的非线性分析越来越多地使用基于Web的网络平台，以实现他们的用户界面，科学分析，分布仿真结果和科学家之间的信息交流。对于许多应用系统基于Web访问的非线性分析模拟软件成为一个重要组成部分。网络硬件和软件方面的密集技术变革[1]提供了比过去更多的自由选择机会[2]。因此，WEB平台的合理选择和发展对整个地区的非线性分析及其众多的应用程序具有越来越重要的意义。现阶段的WEB发展的特点是出现了大量的开源框架。框架将Web开发提到一个更高的水平，使基本功能的重复使用成为可能和从而提高了开发的生产力。 在某些情况下，开源框架没有提供常见问题的一个解决方案。出于这个原因，开发在开源框架的基础上建立自己的工程发展框架。本文旨在描述是一个基于Java的框架，该框架利用了开源框架并有助于开发基于Web的应用。通过分析现有的开源框架，本文提出了新的架构，基本环境及他们用来提高和利用其他一些框架的相关技术。架构定义了自己开发方法，其目的是协助客户开发和事例工程。 应用程序设计应该关注在工程中的重复利用。即使有独特的功能要求，也
Optimum blank design of an automobile sub-frame Jong-Yop Kim a ,Naksoo Kim a,*,Man-Sung Huh b a Department of Mechanical Engineering,Sogang University,Shinsu-dong 1,Mapo-ku,Seoul 121-742,South Korea b Hwa-shin Corporation,Young-chun,Kyung-buk,770-140,South Korea Received 17July 1998 Abstract A roll-back method is proposed to predict the optimum initial blank shape in the sheet metal forming process.The method takes the difference between the ?nal deformed shape and the target contour shape into account.Based on the method,a computer program composed of a blank design module,an FE-analysis program and a mesh generation module is developed.The roll-back method is applied to the drawing of a square cup with the ˉange of uniform size around its periphery,to con?rm its validity.Good agreement is recognized between the numerical results and the published results for initial blank shape and thickness strain distribution.The optimum blank shapes for two parts of an automobile sub-frame are designed.Both the thickness distribution and the level of punch load are improved with the designed blank.Also,the method is applied to design the weld line in a tailor-welded blank.It is concluded that the roll-back method is an effective and convenient method for an optimum blank shape design.#2000Elsevier Science S.A.All rights reserved. Keywords:Blank design;Sheet metal forming;Finite element method;Roll-back method
毕业设计（论文） 外文翻译 题目西安市水源工程中的 水电站设计 专业水利水电工程 班级 学生 指导教师 2016年
研究钢弧形闸门的动态稳定性 牛志国 河海大学水利水电工程学院，中国南京，邮编210098 nzg_197901@https://www.doczj.com/doc/382305989.html,，niuzhiguo@https://www.doczj.com/doc/382305989.html, 李同春 河海大学水利水电工程学院，中国南京，邮编210098 ltchhu@https://www.doczj.com/doc/382305989.html, 摘要 由于钢弧形闸门的结构特征和弹力，调查对参数共振的弧形闸门的臂一直是研究领域的热点话题弧形弧形闸门的动力稳定性。在这个论文中，简化空间框架作为分析模型，根据弹性体薄壁结构的扰动方程和梁单元模型和薄壁结构的梁单元模型，动态不稳定区域的弧形闸门可以通过有限元的方法，应用有限元的方法计算动态不稳定性的主要区域的弧形弧形闸门工作。此外，结合物理和数值模型，对识别新方法的参数共振钢弧形闸门提出了调查，本文不仅是重要的改进弧形闸门的参数振动的计算方法，但也为进一步研究弧形弧形闸门结构的动态稳定性打下了坚实的基础。 简介 低举升力，没有门槽，好流型，和操作方便等优点，使钢弧形闸门已经广泛应用于水工建筑物。弧形闸门的结构特点是液压完全作用于弧形闸门，通过门叶和主大梁，所以弧形闸门臂是主要的组件确保弧形闸门安全操作。如果周期性轴向载荷作用于手臂，手臂的不稳定是在一定条件下可能发生。调查指出:在弧形闸门的20次事故中，除了极特殊的破坏情况下，弧形闸门的破坏的原因是弧形闸门臂的不稳定;此外，明显的动态作用下发生破坏。例如:张山闸，位于中国的江苏省，包括36个弧形闸门。当一个弧形闸门打开放水时，门被破坏了，而其他弧形闸门则关闭，受到静态静水压力仍然是一样的，很明显，一个动态的加载是造成的弧形闸门破坏一个主要因素。因此弧形闸门臂的动态不稳定是造成弧形闸门(特别是低水头的弧形闸门)破坏的主要原是毫无疑问。
外文文献： The Intelligent Building One of the benefits of the rapid evolution of information technology has been the development of systems that can measure, evaluate, and respond to change。An enhanced ability to control change has sparked developments in the way we design our physical environment, in particular, the buildings in which we work。As a result, we are witnessing significant growth in the area of "Intelligent Buildings"--buildings that incorporate information technology and communication systems, making them more comfortable, secure, productive, and cost-effective What is an Intelligent Building? An Intelligent Building is one equipped with the telecommunications infrastructure that enables it to continuously respond and adapt to changing conditions, allowing for a more efficient use of resources and increasing the comfort and security of its occupants。An Intelligent Building provides these benefits through automated control systems such as: heating, ventilation, and air-conditioning (HVAC)；fire safety；security；and energy/lighting management。For example, in the case of a fire, the fire alarm communicates with the security system to unlock the doors。The security system communicates with the HVAC system to regulate the flow of air to prevent the fire from spreading。 What benefits do Intelligent Buildings offer their owners and occupants? The introduction in the workplace of computers printers photocopiers, and fax machines has increased indoor pollution。Electrical and telecommunications facilities in office buildings are under pressure to satisfy the demands created by the rapid growth of computer and networking technologies。These factors have a definite impact on productivity. New technology can be used to create Intelligent Buildings that address these problems by providing a healthier, more productive, and less energy-intensive work environment。As these are critical factors for business
档号：专业代码： 广东理工职业学院顶岗实习报告 系别工程技术系 学生姓名xxx 学生学号xxxx 学生班级10通信技术（1）班 专业名称通信技术 校内指导教师xx 校外指导教师xxx 实习单位xx 2013年4月26日
档 2013年4月26日 目录 一．实习单位介绍 (3) 1.广东超讯通信技术股份有限公司 (3) 二. 实习岗位及主要内容 (4) 1.实习目的 (4) 2.思想和纪律表现 (4) 3.实习岗位（管线割接员、管线，设备录入员） (4) 4.岗位要求及主要工作内容 (4) 三. 实习的主要过程 (5) 1、 autoCAD 以及 zwCAD的使用和看竣工图纸 (6) 2、管线割接 (7) 3、做管线割接方案传输设备工程搬迁、割接工作流程 (8) 4、做管线割接方案 (12) 5、OLT (13) 5、施工现场查勘 (14) 四. 实习总结 (16) 参考文献 (16) 致谢 (16) 附录 (16) 顶岗实习记录表及顶岗实习考核鉴定表················
一、实习单位介绍 1.XXXXX股份有限公司 XXX公司成立于 1998 年，是中国最早从事移动通信网络建设、网络维护、网络优化的公司之一，现已成长为集通信软硬件、系统集成、信息技术服务 一体的高科技企业。目前除在广州设有总部外，还在北京、广州、深圳、广西、 江西、四川、甘肃、内蒙古、海南、湖南、贵州等地建立了省级分公司及研发中心。 公司具备通信信息网络系统集成甲级资质、通信网络代维甲级资 质，已通过高新技术企业、软件企业、安全生产企业、ISO（ISO 9001 质量管理体系， ISO14001 环境管理体系、职业健康安全管理体系）等一系列资格认证。 成立至今，公司已经在通讯行业建立了稳定的市场基础和用户支持群体，并逐渐成为通信技术服务规范的发起者和倡导者。 公司充分发挥自身优势，不断完善、创新服务体系，为中国移动等运营商提供专业、优质的一体化服务。我们的合作伙伴有：中国移动、中国 电信、中国联通。 公司践行“每一比特都精雕细琢”的企业宗旨，秉承“客户、 员工、社会、资本共同获益”的经营理念，自主开发，勇于创新，致力于成为最 优秀的通信技术服务商。 超讯成立于 1998 年，是中国最早从事移动通信网络建设、网络维护、网络优化的 公司之一，现已成长为集通信软硬件、系统集成、信息技术服务一体的高科技企业。目前除在广州设有总部外，还在北京、广州、深圳、广西、江西、四川、
Section 3 Design philosophy, design method and earth pressures 3.1 Design philosophy 3.1.1 General The design of earth retaining structures requires consideration of the interaction between the ground and the structure. It requires the performance of two sets of calculations: 1）a set of equilibrium calculations to determine the overall proportions and the geometry of the structure necessary to achieve equilibrium under the relevant earth pressures and forces; 2）structural design calculations to determine the size and properties of thestructural sections necessary to resist the bending moments and shear forces determined from the equilibrium calculations. Both sets of calculations are carried out for specific design situations (see 3.2.2) in accordance with the principles of limit state design. The selected design situations should be sufficiently Severe and varied so as to encompass all reasonable conditions which can be foreseen during the period of construction and the life of the retaining wall. 3.1.2 Limit state design This code of practice adopts the philosophy of limit state design. This philosophy does not impose upon the designer any special requirements as to the manner in which the safety and stability of the retaining wall may be achieved, whether by overall factors of safety, or partial factors of safety, or by other measures. Limit states (see 1.3.13) are classified into: a) ultimate limit states (see 3.1.3); b) serviceability limit states (see 3.1.4). Typical ultimate limit states are depicted in figure 3. Rupture states which are reached before collapse occurs are, for simplicity, also classified and
附件1：外文资料翻译译文 包装对食品发展的影响 一个消费者对某个产品的第一印象来说包装是至关重要的，包括沟通的可取性，可接受性，健康饮食形象等。食品能够提供广泛的产品和包装组合，传达自己加工的形象感知给消费者，例如新鲜包装/准备，冷藏，冷冻，超高温无菌，消毒（灭菌），烘干产品。 食物的最重要的质量属性之一，是它的味道，其影响人类的感官知觉，即味觉和嗅觉。味道可以很大程度作退化的处理和/或扩展存储。其他质量属性，也可能受到影响，包括颜色，质地和营养成分。食品质量不仅取决于原材料，添加剂，加工和包装的方法，而且其预期的货架寿命（保质期）过程中遇到的分布和储存条件的质量。越来越多的竞争当中，食品生产商，零售商和供应商；和质量审核供应商有显着提高食品质量以及急剧增加包装食品的选择。这些改进也得益于严格的冷藏链中的温度控制和越来越挑剔的消费者。 保质期的一个定义是：在食品加工和包装组合下，在食品的容器和条件，在销售点分布在特定系统的时间能保持令人满意的食味品质。保质期，可以用来作为一个新鲜的概念，促进营销的工具。延期或保质期长的产品，还提供产品的使用时间，方便以及减少浪费食物的风险，消费者和/或零售商。包装产品的质量和保质期的主题是在第3章中详细讨论。 包装为消费者提供有关产品的重要信息，在许多情况下，使用的包装和/或产品，包括事实信息如重量，体积，配料，制造商的细节，营养价值，烹饪和开放的指示，除了法律准则的最小尺寸的文字和数字，有定义的各类产品。消费者寻求更详细的产品信息，同时，许多标签已经成为多语种。标签的可读性是为视障人士的问题，这很可能成为一个对越来越多的老年人口越来越重要的问题。 食物的选择和包装创新的一个主要驱动力是为了方便消费者的需求。这里有许多方便的现代包装所提供的属性，这些措施包括易于接入和开放，处置和处理，产品的知名度，再密封性能，微波加热性，延长保质期等。在英国和其他发达经济体显示出生率下降和快速增长的一个相对富裕的老人人口趋势，伴随着更加苛
毕业设计（论文） 外文文献翻译 题目：A new constructing auxiliary function method for global optimization 学院： 专业名称： 学号： 学生姓名： 指导教师： 2014年2月14日
一个新的辅助函数的构造方法的全局优化 Jiang-She Zhang，Yong-Jun Wang https://www.doczj.com/doc/382305989.html,/10.1016/j.mcm.2007.08.007 非线性函数优化问题中具有许多局部极小，在他们的搜索空间中的应用，如工程设计，分子生物学是广泛的，和神经网络训练．虽然现有的传统的方法，如最速下降方法，牛顿法，拟牛顿方法，信赖域方法，共轭梯度法，收敛迅速，可以找到解决方案，为高精度的连续可微函数，这在很大程度上依赖于初始点和最终的全局解的质量很难保证．在全局优化中存在的困难阻碍了许多学科的进一步发展．因此，全局优化通常成为一个具有挑战性的计算任务的研究． 一般来说，设计一个全局优化算法是由两个原因造成的困难：一是如何确定所得到的最小是全球性的（当时全球最小的是事先不知道），和其他的是，如何从中获得一个更好的最小跳．对第一个问题，一个停止规则称为贝叶斯终止条件已被报道．许多最近提出的算法的目标是在处理第二个问题．一般来说，这些方法可以被类?主要分两大类，即：（一）确定的方法，及（ii）的随机方法．随机的方法是基于生物或统计物理学，它跳到当地的最低使用基于概率的方法．这些方法包括遗传算法（GA），模拟退火法（SA）和粒子群优化算法（PSO）．虽然这些方法有其用途，它们往往收敛速度慢和寻找更高精度的解决方案是耗费时间．他们更容易实现和解决组合优化问题．然而，确定性方法如填充函数法，盾构法，等，收敛迅速，具有较高的精度，通常可以找到一个解决方案．这些方法往往依赖于修改目标函数的函数“少”或“低”局部极小，比原来的目标函数，并设计算法来减少该?ED功能逃离局部极小更好的发现． 引用确定性算法中，扩散方程法，有效能量的方法，和积分变换方法近似的原始目标函数的粗结构由一组平滑函数的极小的“少”．这些方法通过修改目标函数的原始目标函数的积分．这样的集成是实现太贵，和辅助功能的最终解决必须追溯到
电厂蒸汽动力的基础和使用 1.1 为何需要了解蒸汽 对于目前为止最大的发电工业部门来说, 蒸汽动力是最为基础性的。 若没有蒸汽动力, 社会的样子将会变得和现在大为不同。我们将不得已的去依靠水力发电厂、风车、电池、太阳能蓄电池和燃料电池,这些方法只能为我们平日用电提供很小的一部分。 蒸汽是很重要的,产生和使用蒸汽的安全与效率取决于怎样控制和应用仪表,在术语中通常被简写成C&I(控制和仪表 。此书旨在在发电厂的工程规程和电子学、仪器仪表以 及控制工程之间架设一座桥梁。 作为开篇,我将在本章大体描述由水到蒸汽的形态变化,然后将叙述蒸汽产生和使用的基本原则的概述。这看似简单的课题实际上却极为复杂。这里, 我们有必要做一个概述:这本书不是内容详尽的论文,有的时候甚至会掩盖一些细节, 而这些细节将会使热力学家 和燃烧物理学家都为之一震。但我们应该了解,这本书的目的是为了使控制仪表工程师充 分理解这一课题,从而可以安全的处理实用控制系统设计、运作、维护等方面的问题。1.2沸腾:水到蒸汽的状态变化 当水被加热时,其温度变化能通过某种途径被察觉(例如用温度计 。通过这种方式 得到的热量因为在某时水开始沸腾时其效果可被察觉,因而被称为感热。 然而,我们还需要更深的了解。“沸腾”究竟是什么含义?在深入了解之前,我们必须考虑到物质的三种状态:固态,液态,气态。 (当气体中的原子被电离时所产生的等离子气体经常被认为是物质的第四种状态, 但在实际应用中, 只需考虑以上三种状态固态,
物质由分子通过分子间的吸引力紧紧地靠在一起。当物质吸收热量,分子的能量升级并且 使得分子之间的间隙增大。当越来越多的能量被吸收,这种效果就会加剧,粒子之间相互脱离。这种由固态到液态的状态变化通常被称之为熔化。 当液体吸收了更多的热量时,一些分子获得了足够多的能量而从表面脱离,这个过程 被称为蒸发(凭此洒在地面的水会逐渐的消失在蒸发的过程中,一些分子是在相当低的 温度下脱离的,然而随着温度的上升,分子更加迅速的脱离,并且在某一温度上液体内部 变得非常剧烈,大量的气泡向液体表面升起。在这时我们称液体开始沸腾。这个过程是变为蒸汽的过程,也就是液体处于汽化状态。 让我们试想大量的水装在一个敞开的容器内。液体表面的空气对液体施加了一定的压 力,随着液体温度的上升,便会有足够的能量使得表面的分子挣脱出去,水这时开始改变 自身的状态,变成蒸汽。在此条件下获得更多的热量将不会引起温度上的明显变化。所增 加的能量只是被用来改变液体的状态。它的效用不能用温度计测量出来,但是它仍然发生 着。正因为如此,它被称为是潜在的,而不是可认知的热量。使这一现象发生的温度被称为是沸点。在常温常压下,水的沸点为100摄氏度。 如果液体表面的压力上升, 需要更多的能量才可以使得水变为蒸汽的状态。 换句话说, 必须使得温度更高才可以使它沸腾。总而言之,如果大气压力比正常值升高百分之十,水必须被加热到一百零二度才可以使之沸腾。