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Signaling positioning technology provides a new opportunity to understand an individual’s travel characteristics. In recent studies, the travel parameters obtained are mainly macroscopic travel information. However, extracting detailed trip chain information, such as the trip mode and mode-switching time point, remains a challenge. Furthermore, because of the iterative development of wireless networks, existing communication operators usually store different frequencies and accuracy (2G/3G and 4G) of signaling data simultaneously, making the refined identification of travel information more difficult. Therefore, this paper proposes a new method. First, we use the shortest distance algorithm to match the signaling data with the road network. Second, a wavelet transform modulus maximum (WTMM) algorithm is proposed to divide multimodal travel trajectories into single-mode trip segments; thus, spatiotemporal information related to mode transfer can be obtained. Finally, an unsupervised fuzzy kernel c-means clustering (FKCM) algorithm is proposed to distinguish travel modes. As comparison data, smartphone GPS and travel log data are also collected to analyze the detection result and improve the method. The identification errors of mode-switching time points at different frequencies are all less than 360 s. The average correct rate of traffic mode identification for 2G is 65.1%, and the average correct rate of traffic mode identification for 3G is 78.2%. 4G intensive cellular positioning data has a significantly better recognition effect than low-frequency data; the average trip mode detection accuracy reaches 89.6%, and the mode-switching time point detection errors are within 300 s.

PurposeBy adopting learning theory and a guanxi perspective, this study aims to investigate the effects of interpersonal guanxi (interpersonal networks or connections) and relationship learning on companies’ business performance when operating in a large emerging market.Design/methodology/approachUsing a sample of 294 sales managers and salespeople in the Chinese hotel sector, the authors empirically test the authors' arguments through a structural equation modeling (SEM) approach.FindingsThe authors' findings indicate that strong interpersonal guanxi tends to generate more positive business performance. Furthermore, the authors find that relationship learning plays a mediating role in the association between interpersonal guanxi and hotel companies’ business performance in a Chinese context. Finally, the authors empirically explore the moderating effect of inter-firm dependence on the contribution of interpersonal guanxi to relationship learning. Findings demonstrate that this effect varies significantly based on inter-firm dependence, with interpersonal guanxi exhibiting a greater positive impact if such dependence is high.Originality/valueThis study enriches our understanding of interpersonal guanxi and of how companies can enhance the companies' business performance in an emerging market context.

A–π–D–π–A type conjugated small molecules play an indispensable role in organic photovoltaics. Understanding the relationship between the molecular structure and performance is a fundamental question for the further rational design of high-performance organic materials. To red-shift the absorption spectrum of benzo[1,2-b:4,5-b']dithiophene (BDT) based A–π–D–π–A type compounds, an electron-donating 3,4-ethylenedioxythiophene (EDOT) moiety was introduced into the π-conjugation bridge unit. Two new compounds with EDOT next to the central BDT core (COOP-2HT-EDOT-BDT) or next to the terminal electron acceptor unit (COOP-EDOT-2HT-BDT) were synthesized and characterized. The compound COOP-2HT-EDOT-BDT showed higher molar extinction coefficient (εabs max = 1.06 × 105 L mol−1 cm−1), lower optical band gap (E g = 1.56 eV) and high HOMO energy level (E HOMO = −5.08 eV) than COOP-EDOT-2HT-BDT (εabs max = 0.96 × 105 L mol−1 cm−1, E g = 1.71 eV, E HOMO = −5.26 eV), which is attributed to the intensive interaction between the EDOT unit and the HOMO orbital, as confirmed by the theoretical calculation results. However, the higher power conversion efficiency of 3.58% was achieved for the COOP-EDOT-2HT-BDT:PC61BM-based solar cells, demonstrating that the electron-donating EDOT unit adjacent to the electron-withdrawing end-capped group (COOP) is a better way to achieve high-performance photovoltaic materials.

Dissatisfied customers are increasingly voicing complaints through social media following online service failures; therefore, it is important to clarify the motivational determinants of customers' online complaint intentions (COCI). We investigated in 3 studies the influence and interaction effects of service failure types, attributions about these failures, scope of impact of the failures, and customer inoculation on both public and private online complaint intentions. Participants were 451 college students from Hainan Province, China. The results show that service failure types, service failure attributions, scope of impact of the service failure, and customer inoculation each had distinct effects on COCI and how customers complain online, and that these factors also had interactive effects on online complaint actions. Our finding that the form of COCI can predict service failure attributes offers implications for the implementation of enterprise service recovery from a consumer perspective.

PurposeThe purpose of this paper is to examine the threshold effect of group size on customer's complaining intention under group service failures.Design/methodology/approachBased on two main laboratory experiments, through two 10×2 scenario simulation experiments, the authors examine the role of group size in customer's complaining intention.FindingsResults show that: (1) the relationship between group size and customer's complaining intention follows an inverted “U” type trend; (2) evaluation apprehension mediates the relationship between group size and customer's complaining intention; (3) relational distance can change threshold values and (4) relational distance moderates the relationship between group size and customer's complaining intention.Practical implicationsManagers should judge the threshold of group size through experience so as to have a preliminary understanding of customer evaluation concerns and complaint intention. In the face of service failure groups smaller than the threshold range, managers should divided the group into several small groups. For service failure groups larger than the threshold range, the opinion leaders in the group should be given more attention, so as to control the whole group.Social implicationsThis paper is helpful to deeply understand the key role of group size in the process of customer complaints, and also provides decision-making basis for service enterprises to deal with group customer complaints.Originality/valueThere has been little research about the threshold effect of group size on customer's complaining intention. The previous studies on customer's complaining intention focus on its influences on group size, and draw a single common conclusion that the customer's intention to complain will increase with the growing number of groups increases. However, few studies are explored on the threshold of group size. Therefore, this paper will focus on the threshold effect of group size on customer's complaining intention to fill the gap.

We propose and fabricate a polymeric thermo-optic mode switch based on a Mach-Zehnder interferometer (MZI) by connecting two asymmetric directional couplers formed with a single-mode waveguide (SMW) and a two-mode waveguide (TMW). Thin-film heaters were deposited on the arms of the MZI to realize the switching function. The LP01 mode in the SMW and the LP11a mode in the TMW can be converted to each other by driving the voltage supplied to the heater. Our typical fabricated device with polymer material shows extinction ratios higher than ~11 dB in the C-band. The switching power measured at 1550 nm is lower than 10 mW and the switching rise time and fall time are $540.0~\mu \text{s}$ and $440.0~\mu \text{s}$ , respectively. The device could find applications in reconfigurable mode-division-multiplexing systems.

This study proposes a new model of brand equity for self-driving route along the Silk Road, in which brand-self congruity, brand awareness, and perceived quality mediate the relationship between br...

The Bohai Bay Basin is very rich in heavy oil. Generally the water flooding recovery of heavy oil reservoirs is only 18-20% in Bohai Oilfield, which has great potential for EOR. Being a mature technology in onshore oilfields, polymer flooding in Bohai Oilfield faces a serious of difficulties including choosing the best polymer injection opportunity in limited platform life, poor applicability of existing polymers and polymer preparation and production fluid treatment restricted by platform space. In recent years, several large heavy oil fields have carried out chemical flooding test. In order to solve the above problems, the early stage polymer injection development mode which breaks the limit of secondary and tertiary oil recovery was practiced to fit the service life of platform; a new kind of hydrophobic associative polymer was designed to meet the demand of viscous crude oil, high hardness water, strong shear force and large well spacing in Bohai Oilfield; a serious new facilities used for polymer instant solution and production fluid treatment was designed to fit the narrow space of platform. The tests show that the early stage polymer injection development mode in offshore heavy oil fields has achieved good results. It effectively reduces or stabilizes the water cut and increases oil production significantly. Based on the good test results, the scale of injection test in Bohai Oilfield expands continuously. It develops from 1 injection and 5 production in a single well group to 44 injection and 171 production in three oilfields, with polymer flooding reserves reaching 144×106m3. According to statistics, in the recent 5 years, the cumulative oil production of polymer flooding has reached 5.651×106m3, and the recovery rate is increased by 3.9%, which is expected to be 8% in the future. Successful application of the technologies has significantly improved the development effect of offshore heavy oilfields. Even in the low oil price period, it has created tremendous economic value for the company. Nowadays polymer flooding has become a necessary means of stabilizing oil and controlling water in old oilfields in Bohai.

Two perylenediimide derivatives (3T-PDI2 and 6T-PDI4) based on dendritic terthiophene (3T) and sexithiophene (6T) cores were designed and synthesized. The rigid and dendritic oligothiophene core ensures a non-planar structure of these two compounds, which was confirmed by theoretical molecular structure simulation. The optical and electrochemical investigation results showed that both compounds have similar LUMO energy level of −4.1 eV, demonstrating that the LUMO orbital is mainly localized on the PDI moiety. Polymer solar cells using 3T-PDI2 and 6T-PDI4 as the electron acceptor, and PTB7-Th as the donor were fabricated and tested. A power conversion efficiency (PCE) of 4.12% was obtained for the 6T-PDI4 based device, which is higher than that of 3T-PDI2 based device (3.41%). Higher charge carrier mobility and less Shockley-Read-Hall recombination were also measured for the 6T-PDI4 based device. The current work demonstrates that dendritic PDI derivatives could serve as non-fullerene acceptor for use in polymer solar cells.

A-π-D-π-A type conjugated small molecules ( COOP-nHT-BDT (n=1–4)) with a benzo[1,2-b:4,5-b']dithiophene (BDT) as the electron-donating core, 2-cyano-3-octyloxy-3-oxo-1-propenyl (COOP) as the terminal electron-accepting unit, and two regioregular oligo(3-hexylthiophene) (nHT) as π-conjugated bridges were synthesized and characterized. TGA results confirmed that all these compounds are thermally stable with decomposition temperatures higher than 340 °C. Broad absorption bands over 350 to 600 nm with small optical band gaps (E g opt ) of 1.9–1.8 eV were measured for these compounds. Cyclic voltammetry measurements indicated that HOMO energy level of these COOP-nHT-BDTs increases slightly with the increase of nHT chain length, whereas all these compounds display similar LUMO energy level of −3.60 eV. These were supported by density function calculation results, that electronic wave functions of the HOMO orbitals are delocalized over the BDT-core with the adjacent 2–3 thiophene units, whereas the electronic wave functions of the LUMO orbital are mostly localized on the terminal COOP unit with 1–2 thiophene units. Gradually increasing of the photovoltaic performance was found for these compounds with the increase of the π-bridge chain length, and the COOP- 4HT-BDT /PC 71 BM (2:1, w/w) based device displayed a best power conversion efficiency of 5.14% with an open circuit voltage of 0.90 V, a short circuit current of 8.27 mA cm −2 and a fill factor of 0.69. A positive correlation between long-term stability of PCE and chain length was also obtained. COOP- 4HT-BDT based devices showed the highest device stability with only 15% decay after 320 h continuous illumination.

In this paper, an integrated processing method was demonstrated to fabricate the polymer-based thermo-optic (TO) switch with low power consumption. The characteristic parameters of the switch were carefully designed and simulated. The air trench structure was exploited to reduce the power consumption, which can be formed with the waveguide simultaneously by the integrated processing method. Moreover, the introduced polymer/silica hybrid waveguide structure can also improve the response time of the device. A typical fabricated switch presented a low switching power of 5.2 mW. The measured switching rise time and fall time are 192.2 and 201.1 μs, respectively.

This study investigates a multiple mediation model, in which the effects of social interaction among members of virtual travel communities operated by online travel agency brands on brand attachment are mediated by five dimensions of social well-being. Data were collected from 375 customers of virtual travel communities who had interacted with other customers in those communities online. Findings suggest that (1) the positive effects of online customer-to-customer social interaction (CCSI) on brand attachment are mediated by five social well-being dimensions, (2) CCSI is positively related to five social well-being dimensions and brand attachment, and (3) five social well-being dimensions have significant influences on brand attachment. This study provides empirical evidence of how online CCSI in virtual travel communities can improve customers’ social well-being and brand attachment.

The construction of a new family of multiferrocenes end-capped metallodendrimers H1–4 with various generations via coordination-driven self-assembly was described. The structures of these metallodendrimers H1–4 were characterized by multinuclear NMR { 1 H and 31 P} spectroscopy, electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS), and the PM6 semiempirical molecular orbital method. Insight into the structure and electronic properties of these supramolecules was obtained through electrochemical studies.

We design and fabricate a thermo-optic waveguide switch based on the configuration of a balanced Mach–Zehnder interferometer optimized for fast operation. The structure of the waveguides consists of two core layers with the lower layer formed with the high-index organic–inorganic hybrid material DR1/SiO2−TiO2. The hybrid material allows the mode field to be confined in an area for fast heat removal, and the formation of index tapers to expand the mode field at the two ends of the device to facilitate butt-coupling with single-mode fibers. Our typical fabricated device shows the same rise time and fall time of 80 μs and low switching power of 8.9 mW at the wavelength of 1550 nm.

Accurate transfer demand prediction at bike stations is the key to develop balancing solutions to address the overutilization or underutilization problem often occurring in bike sharing system. At the same time, station transfer demand prediction is helpful to bike station layout and optimization of the number of public bikes within the station. Traditional traffic demand prediction methods, such as gravity model, cannot be easily adapted to the problem of forecasting bike station transfer demand due to the difficulty in defining impedance and distinct characteristics of bike stations (Xu et al. 2013). Therefore, this paper proposes a prediction method based on Markov chain model. The proposed model is evaluated based on field data collected from Zhongshan City bike sharing system. The daily production and attraction of stations are forecasted. The experimental results show that the model of this paper performs higher forecasting accuracy and better generalization ability.

Two conjugated A-pi-D-pi-A type small molecules having a 4,8-bis(thieny1)-benzo[1,2-b:4,5-b'] dithiophene (TBDT) unit as the donor part, a mono-thiophene as the pi-conjugation bridge, and 2-cyano-3-octyloxy-3-oxo-1-propenyl (COOP) or dicyanovinyl (DCV) as the terminal acceptor unit were synthesized and investigated. Both compounds showed broad absorption band over 400-600 nm and similar HOMO/LUMO energy levels. However, these two compounds showed a big difference in photovoltaic performance. The DCV-1T-TBDT:PC61BM based solar cell exhibited an open circuit voltage (V-oc) of 0.93 V, a short circuit current (Jsc) of 8.54 mA cm(-2), a fill factor (FF) of 0.56, and an overall power conversion efficiency (PCE) of 4.48%, whereas the COOP-1T-TBDT:PC61BM based solar cell showed a V-oc of 1.04 V, a Jsc of 2.28 mA cm(-2), an FF of 0.29, and a PCE of 0.69. Furthermore, DCV-1T-TBDT showed minor thickness-dependent PCE behavior in PV device, which is beneficial for printing processing. (C) 2015 Elsevier Ltd. All rights reserved.

Three 2,2-dicyanovinyl (DCV) end-capped A-pi-D-pi-A type oligothiophenes (DCV-OTs) containing dithieno[3,2-b: 2',3'-d] silole (DTSi), cyclopenta[1,2-b: 3,4-b'] dithiophene (DTCP) or dithieno[3,2-b: 2',3'-d] pyrrole (DTPy) unit as the central donor part, mono-thiophene as the pi-conjugation bridge were synthesized. The absorption spectroscopies, cyclic voltammetry of these compounds were characterized. Results showed that all these compounds have intensive absorption band over 500-680 nm with a LUMO energy level around -3.80 eV, which is slightly higher than that of [6,6] phenyl-C-61-butyric acid methyl ester (PC61BM, E-LUMO = -4.01 eV), but lower than that of poly(3-hexylthiophene) (P3HT, ELUMO = -2.91 eV). Solution processed bulk heterojunction "all-thiophene'' solar cells using P3HT as electron donor and the above mentioned oligothiophenes as electron acceptor were fabricated and tested. The highest power conversion efficiency (PCE) of 1.31% was achieved for DTSi-cored compound DTSi(THDCV) 2, whereas PTB7: DTSi(THDCV) 2 based device showed slightly higher PCE of 1.56%. Electron mobilities of these three compounds were measured to be around 10 (5) cm(2) V (1) s (1) by space charge limited current method, which is much lower than that of PC61BM, and was considered as one of the reason for the low photovoltaic performance. (C) 2015 Elsevier B.V. All rights reserved.

Dieser Artikel schildert den Einsatz von Tuina bei Dysmenorrhoe, die eine sehr gute Behandlungsalternative darstellt. Dabei ist grundsatzlich zwischen einer depletio (energetische Schwache, xu) und einer repletio (energetische Uberladung, shi) zu differenzieren, in beiden Fallen sollten aber Qi und Xue durchgangiggemacht und reguliert werden. Um dieses Ziel zu erreichen, konnen verschiedene Tuina-Techniken eingesetzt werden. Die Autoren beschreiben sieben konkrete Vorgehensweisen, die im Lumbalbereich, am Abdomen oder an den Oberschenkeln durchzufuhren sind. Eine besondere Rolle spielen dabei die drei cardinales impares (Unpaarige Leitbahnen, qijing) sinarteria impedimentalis („Breite Trossstrase“, chongmai), sinarteria respondens („Aufnehmende Leitbahn“, renmai) und sinarteria regens („Leitbahn der Steuerung“, dumai). Die Autoren illustrieren ihre Ausfuhrungen mit zwei Fallbeispielen, bevor sie im letzten Teil des Artikels auf wichtige Punkte hinweisen. So nennen sie Punkte und Regionen, die bei Dysmenorrhoe typischerweise vor der Menstruation empfindlich werden, und sie gehen auf die Moglichkeit ein, bei Menstruationsschmerzen auch am Abdomen Tuina durchzufuhren.

We propose and demonstrate a high-resolution and fast-response optical waveguide temperature sensor based on asymmetric Mach-Zehnder interferometer (MZI) structure. The sensing region is composed of an asymmetric MZI structure, which consists of two different kinds of cores formed with commercial polymer materials EpoClad and Norland optical adhesive 73 (NOA 73), respectively, in the two arms. Due to the higher thermo-optic coefficient of NOA 73, the phase changes of the two MZI arms are different with the temperature which in turn induces output optical power variations, enabling simple and real-time temperature detection. The sensor exhibits a large sensitivity of −1.685 °C−1, high resolution of 1.48 × 10−3 °C and fast response time of about 510 μs. The advantages of high sensitivity and resolution, low-cost, competent integration and compatible with most biological assays make the designed sensor potential application in temperature detections of molecular analysis, biotechnology and chemical synthesis.

Optical polymer is one of the promising materials for photonic integrated devices that can be processed with simple, flexible and semiconductor compatible technology. Especially, optical polymer with the advantages of high thermo-optic (TO) and electro-optic (EO) coefficients has been widely applied in optical waveguide switches. However, most of the current optical switches are independent with single function. It is essential to develop an on-chip integrated device with multilayer for signal manipulation. In this paper, we propose an on-chip 3-dimensional integrated optical switch based on the EO polymer-clad waveguide incorporate with the TO tunable vertical coupler. The proposed integrated optical switch could realize the function-integration of the adjustable 3D optical connection and the high-speed modulation. A typical fabricated switch shows an insertion loss of 16.3 dB and an extinction ratio of 16.0 dB at the driving power of 48.2 mW. The dynamic characteristics of TO and EO switching functions of the device were also measured in this work.

We proposed and designed an ultra-sensitive polymeric waveguide temperature sensor based on an asymmetric Mach–Zehnder interferometer that has different widths in the two interferometer arms. A polymer with a larger thermo-optic coefficient (TOC) was employed to enhance the sensitivity of the waveguide temperature sensor. The influence of the width difference between the two arms and the cladding materials with different TOCs on the sensitivity of the sensor was studied and experimentally demonstrated. The devices were fabricated by using the standard photolithography and simple all-wet etching process. When the cladding material Norland optical adhesive 73 (NOA 73) and the width difference of 6.5 μm were selected, the sensitivity of the waveguide temperature sensor was measured to be 30.8 nm/°C. Moreover, the minimum temperature resolution was about 0.97×10−3°C. The proposed sensor has the distinct advantages of high sensitivity, high resolution, easy fabrication, low cost, and biological compatibility, which make it have potential applications in temperature detection of organisms, molecular analysis, and biotechnology.

A new family of 60° dendritic di-Pt(II) acceptor tectons have been successfully designed and synthesized, from which a series of novel "three-component" triangular metallodendrimers were prepared via [3 + 3] coordination-driven self-assembly. The structures of newly designed triangular metallodendrimers are characterized by multinuclear NMR ((1)H and (31)P), (1)H DOSY NMR, mass spectrometry (CSI-TOF-MS), and elemental analysis. The shape and size of all supramolecular dendritic triangles were investigated with PM6 semiempirical molecular orbital methods.

BACKGROUND CrgA based PCR are usually used for diagnosis of Neisseria meningitidis while the crgA gene was observed in the genomes of Haemophilus influenzae. In this study, we aimed to evaluate whether the crgA primers routinely used in the diagnosis of N. meningitidis could cross react with H. influenzae isolates. METHODS A diagnostic test study analysis of sixty-two H. influenzae isolates from oropharyngeal swabs of healthy individuals aged 9 to 11 years between 2011 and 2012, using commonly used crgA primers for diagnostic analysis of N. meningitidis. RESULTS It revealed that 19.3% nontypable H. influenzae isolates were positive for the crgA gene. All the biotype IV H. influenzae isolates were crgA PCR positive. CONCLUSIONS Our study has shown a significant finding of crgA gene especially in bitotype IV nontypable H. influenzae by N. meningitidis crgA diagnostic PCR primers. It is necessary to further evaluate the prevalence of the crgA gene in more non-typable H. influenzae strains, particularly invasive strains.

Machine type communications (MTC) is defined as data communication among devices without the need for human interaction. With the decommissioning of legacy cellular systems, migration of MTC devices to LTE is under investigation by many operators. It is desirable that the cost of LTE MTC devices is similar to that of existing GSM devices. Several cost reduction techniques have been studied. This paper summarizes cost reduction techniques for MTC devices and examines system impacts from such devices being introduced in LTE. Performance is evaluated for the Advanced Metering Infrastructure used in smart grid. It is seen that LTE offers significant capacity for smart metering even with low-cost devices. For a system with 10 MHz bandwidth, approximately 2% of the system resource is required to support AMI in an urban deployment scenario.

Time division duplex long term evolution (TD-LTE) system specified by the 3rd Partnership Project (3GPP) supports beamforming which can fully exploit channel reciprocity. And spatial mulplexing such as dual layer based beamforming has been supported on release 9 of the 3GPP specification in recent years. The performance of beamforming utilizing channel reciprocity depends on the accuracy of the channel state obtained by the base station (BS). The critical factor in this respect is the density of the sounding reference signal (SRS) transmitted from the terminal. Moreover terminals are not required to support sounding from all receiving antennas so this behavior is supposed to impact the dual-layer beamforming performance heavily. In this paper we investigate the impact on the performance of average and coverage throughput from practical sounding limitations and the evaluation results show that performance losses are negligible in most cases. For the special case of dual layer transmission with single antenna sounding we propose two beamforming schemes, all of which utilize the combination of long-term beamformer and inter-stream orthogonality criteria (but different criteria for the two schemes) to maximize performance. The simulation results show that the proposed schemes could guarantee the dual-layer beamforming performance even in case of very sparse sounding resource.

More than 80% oil resources were heavy oil in Bohai Bay of China. Generally, we used water flooding in the reservoirs with the viscosity less than 400cp. But there were many challenges during water injection in conventional heavy oil reservoirs because high oil-water viscosity ratio lead quick breakthrough of injecting water. And with the oil-water viscosity ratio increasing, the breakthrough of injecting water became more serious. In order to solve these problems, the gel treatments on the injection wells pilot test were conducted in x oilfield during the year 2009 to 2011. Before pilot test, laboratory study under field conditions was conducted to determine the chemical parameters of the gel. We also did numerical simulation study with CMG. A range of variation of critical parameters was evaluated in the simulation for understanding the gelation process undergroud. The model was used to predict the reservoir response under different chemical parameters. Results from simulation showed that water cut reduction ranged from 15.9 to 36.6% which matched the trends observed in wells. On the other hand, dynamic method was also used to evaluate the gel pilot test. The Hall curve analysis was used to evaluate the effectiveness of the injection well and to calculate the resistance factor (RF) & residual resistance factor (RRF) (RF from 1.82 to 6.88, and RRF from 1.29 to 7.97). The decline curve analysis was used to obtain net incremental oil by gel injection treatment. Results from two well patterns conducted gel pilot test in 2009 indicated that water cut reduction ranged from 3.2 to 36.8% and average oil production increases 15.7m3/d. Based on results, another two wells in 2010 and two wells in 2011 were conducted, and we received good effectiveness by gel treatments. The pilot test & evaluation technology provide the foundation for promoting application of techniques to stabilize oil rate and control water production in conventional heavy oil reservoirs of China offshore oilfield

An AlGaAs laser diode (slave laser) has been frequency-locked to a Fabry-Perot interferometer which is locked to a diode laser (master laser) beam frequency-locked to the D(2) line of a Cs atomic beam. Frequency-locking of the Fabry-Perot interferometer to the master laser beam frequency-locked to a resonance line of an atomic beam greatly improves its long-term frequency stability. Therefore, it substantially improves the slave laser diode frequency stability frequency-locked to it. The measured frequency stabilities show that the very high frequency stability of the D(2) line of a Cs atomic beam has been transferred to the slave laser by this frequency-locking system within 1.6 x 10(-11)(10s). This system can be used for building a network of diode lasers with high frequency stability.

LTE Release 9 supports a new DL transmission mode which combines UE specific beamforming and spatial multiplexing. As one option this transmission mode can be operated based on UE (user equipment) feedback of channel rank. However in this case, the rank is in many cases not very accurate due the difference in precoding between the signal used for data demodulation (DRS - dedicated reference signal) and the signal used for estimating rank (CRS - common reference signal). To maintain good performance it is necessary to introduce a compensation factor to inform the UE about the difference between the channel experienced on DRS and CRS to obtain reasonable rank indication (RI). In this paper we study two compensation schemes, named UE-specific scheme and cell-specific scheme. System level simulations are used to validate the performance of the proposed schemes and support the view that cell-specific compensation is sufficient.

IEEE 802.16 systems adopt a "semi-dynamic" allocation mechanism of channel quality indicator (CQI) channels. However, low utilization ratio of CQI channels reduces the spectrum efficiency. So we propose three adjusting strategies based on a "toy brick model" to improve the utilization ratio of CQI channels. The simulation results manifest the improvement. In addition, we analyze the tradeoff between the increase of utilization ratio and the increase of signaling overhead.