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1
Tang, Xu, Shuanggen Jin, and Gethin Wyn Roberts. "Prior Position- and ZWD-Constrained PPP for Instantaneous Convergence in Real-Time Kinematic Application." Remote Sensing 13, no. 14 (July 13, 2021): 2756. http://dx.doi.org/10.3390/rs13142756.
Повний текст джерелаАнотація:
PPP using Kalman filter typically takes half an hour to achieve high positioning precision, which is required for small movements detection. Many dataset gaps due to temporary GPS receiver signal loss challenge the feasibility of PPP in GPS applications for kinematic precise positioning. Additional convergence time is needed before PPP reaches the required precision again. In this study, Partial parameters were estimated by using the position and ZWD as prior constraint. The solved partial parameters were applied to initialize the Kalman filter for PPP instantaneous re-convergence. A set of bridge GPS data with logging gaps were used to validate the re-convergence performance of improved PPP. The results show that the displacements from position-constrained PPP with initialized variance are 0.14 m, 0.09 m and 0.05 m, which are much better than those from standard PPP. The precision of displacement from position- and ZWD-constrained PPP with initialized variance is slightly improved when compared with that from position-constrained PPP with initialized variance at all 3 surveying points. The bridge experiment verifies that the displacement time series of improved PPP instantaneously converges at the first epoch of all signal reacquired, in contrast, standard PPP deviates by meters. This finding suggests that improved PPP can successfully deal with the GPS data logging gaps for instantaneous convergence.
2
Su, Ke, Shuanggen Jin, and M. Hoque. "Evaluation of Ionospheric Delay Effects on Multi-GNSS Positioning Performance." Remote Sensing 11, no. 2 (January 17, 2019): 171. http://dx.doi.org/10.3390/rs11020171.
Повний текст джерелаАнотація:
Ionospheric delay is a significant error source in multi-GNSS positioning. We present different processing strategies to fully exploit the ionospheric delay effects on multi-frequency and multi-GNSS positioning performance, including standard point positioning (SPP) and precise point positioning (PPP) scenarios. Datasets collected from 10 stations over thirty consecutive days provided by multi-GNSS experiment (MGEX) stations were used for single-frequency SPP/PPP and dual-frequency PPP tests with quad-constellation signals. The experimental results show that for single-frequency SPP, the Global Ionosphere Maps (GIMs) correction achieves the best accuracy, and the accuracy of the Neustrelitz TEC model (NTCM) solution is better than that of the broadcast ionospheric model (BIM) in the E and U components. Eliminating ionospheric parameters by observation combination is equivalent to estimating the parameters in PPP. Compared with the single-frequency uncombined (UC) approach, the average convergence time of PPP with the external ionospheric models is reduced. The improvement in BIM-, NTCM- and GIM-constrained quad-constellation L2 single-frequency PPP was 15.2%, 24.8% and 28.6%, respectively. The improvement in convergence time of dual-frequency PPP with ionospheric models was different for different constellations and the GLONASS-only solution showed the least improvement. The improvement in the convergence time of BIM-, NTCM- and GIM-constrained quad-constellation L1/L2 dual-frequency PPP was 5.2%, 6.2% and 8.5%, respectively, compared with the UC solution. The positioning accuracy of PPP is slightly better with the ionosphere constraint and the performance of the GIM-constrained PPP is the best. The combination of multi-GNSS can effectively improve the positioning performance.
3
Jiang, Yong. "Selection of PPP Projects in China Based on Government Guarantees and Fiscal Risk Control." International Journal of Financial Research 8, no. 1 (December 8, 2016): 99. http://dx.doi.org/10.5430/ijfr.v8n1p99.
Повний текст джерелаАнотація:
Public-Private Partnership (PPP) is an effective investment channel for government to provide public services. PPPs have the advantage of transferring some project risk to the private sector. They also imply that the public sector should establish appropriate laws and regulations to enable government departments to effectively avoid the emergence of new fiscal risks, which may affect the sustainability of fiscal budgets. This paper expounds the fiscal risks implied by PPP projects in China and the status of government guarantees in various forms of PPP projects; chance-constrained goal-programming (CCGP) is used to simulate government project selection under budget and risk control constraints. The analysis takes fiscal space, the expected costs and benefits of government guarantees, and the possibility of excess government subsidies into consideration. Constrained by fiscal risk minimization and budget limitations, PPP projects with government guarantees can maximize social-economic net present value and simultaneously optimize welfare. The paper also puts forward corresponding policy recommendations based on the research findings.
4
Wang, Ren, Jingxiang Gao, Nanshan Zheng, Zengke Li, Yifei Yao, Long Zhao, and Yifan Wang. "Research on Accelerating Single-Frequency Precise Point Positioning Convergence with Atmospheric Constraint." Applied Sciences 9, no. 24 (December 10, 2019): 5407. http://dx.doi.org/10.3390/app9245407.
Повний текст джерелаАнотація:
An increasing number of researchers have conducted in-depth research on the advantages of low-cost single-frequency (SF) receivers, which can effectively use ionospheric information when compared to dual-frequency ionospheric-free combination. However, SF observations are bound to increase the unknown parameters and prolong the convergence time. It is desirable if the convergence time can be reduced by external information constraints, for example atmospheric constraints, which include ionosphere- or troposphere constraints. In this study, ionospheric delay constraints, tropospheric delay constraints, and their dual constraints were considered. Additionally, a total of 18,720 test experiments were performed. First, the nearest-neighbor extrapolation (NENE), bilinear- (BILI), bicubic- (BICU), and Junkins weighted-interpolation (JUNK) method of Global Ionospheric Map (GIM) grid products were analyzed. The statistically verified BILI in the percentage of convergence time, average convergence time, and computation time consumption of them shows a good advantage. Next, the influences of global troposphere- and ionosphere-constrained on the convergence time of SF Precise Point Positioning (PPP) were analyzed. It is verified that the ionosphere-constrained (TIC2) has significant influence on the convergence time in the horizontal and vertical components, while the troposphere-constrained (TIC1) has better effect on the convergence time in the vertical components within some thresholds. Of course, the dual constraint (TIC3) has the shortest average convergence time, which is at least 46.5% shorter in static mode and 5.4% in kinematic mode than standard SF PPP (TIC0).
5
Lu, Cuixian, Florian Zus, Maorong Ge, Robert Heinkelmann, Galina Dick, Jens Wickert, and Harald Schuh. "Tropospheric delay parameters from numerical weather models for multi-GNSS precise positioning." Atmospheric Measurement Techniques 9, no. 12 (December 13, 2016): 5965–73. http://dx.doi.org/10.5194/amt-9-5965-2016.
Повний текст джерелаАнотація:
Abstract. The recent dramatic development of multi-GNSS (Global Navigation Satellite System) constellations brings great opportunities and potential for more enhanced precise positioning, navigation, timing, and other applications. Significant improvement on positioning accuracy, reliability, as well as convergence time with the multi-GNSS fusion can be observed in comparison with the single-system processing like GPS (Global Positioning System). In this study, we develop a numerical weather model (NWM)-constrained precise point positioning (PPP) processing system to improve the multi-GNSS precise positioning. Tropospheric delay parameters which are derived from the European Centre for Medium-Range Weather Forecasts (ECMWF) analysis are applied to the multi-GNSS PPP, a combination of four systems: GPS, GLONASS, Galileo, and BeiDou. Observations from stations of the IGS (International GNSS Service) Multi-GNSS Experiments (MGEX) network are processed, with both the standard multi-GNSS PPP and the developed NWM-constrained multi-GNSS PPP processing. The high quality and accuracy of the tropospheric delay parameters derived from ECMWF are demonstrated through comparison and validation with the IGS final tropospheric delay products. Compared to the standard PPP solution, the convergence time is shortened by 20.0, 32.0, and 25.0 % for the north, east, and vertical components, respectively, with the NWM-constrained PPP solution. The positioning accuracy also benefits from the NWM-constrained PPP solution, which was improved by 2.5, 12.1, and 18.7 % for the north, east, and vertical components, respectively.
6
Luo, Jian Guo, and Jian You Han. "New Type of PPP-S[T]-PPP Hybrid Cubic Manipulator." Advanced Materials Research 181-182 (January 2011): 516–21. http://dx.doi.org/10.4028/www.scientific.net/amr.181-182.516.
Повний текст джерелаАнотація:
A new type of hybrid cubic manipulator with six degree of freedom(DOF) suggested based on traditional serial manipulator and parallel manipulator, three dimensional translation and rotation of output shaft obtained through lineal driving. Define the description of spacial moving capability of common couples and translation base and rotation base of mechanism, based on the fact of mechanism consists of components, a new description method by topological graph theory of components relationship suggested, new description of serial mechanism and parallel mechanism and hybrid mechanism obtained with this method, description elements include component pane and constrained component pane and component relationship line and constrained component relationship line and spacial relative moving capability between adjacent components. DOF(degree of freedom) of hybrid mechanism analysised with example based on the definition of dimensionity of branch spacial moving capability and mechanism spacial moving capability, necessary and sufficient condition of nonsingularity of mechanism presented. Method of analytic geometry used to find the regular cuboid of the reachable working space shape of mechanism, the volume of the reachable working space rest with the limit of translation of couplers, its influential factors obtained, still the rotational angle limits of output shaft at given configuration analysised through the method of drawing, and limit length of guideway etc. are the primary influential factors.
7
Wang, Chen, Zhang, Meng, and Wang. "Performance of Selected Ionospheric Models in Multi-Global Navigation Satellite System Single-Frequency Positioning over China." Remote Sensing 11, no. 17 (September 3, 2019): 2070. http://dx.doi.org/10.3390/rs11172070.
Повний текст джерелаАнотація:
Ionospheric delay as the major error source needs to be properly handled in multi-GNSS (Global Navigation Satellite System) single-frequency positioning and the different ionospheric models exhibit apparent performance difference. In this study, two single-frequency positioning solutions with different ionospheric corrections are utilized to comprehensively analyze the ionospheric delay effects on multi-frequency and multi-constellation positioning performance, including standard point positioning (SPP) and ionosphere-constrained precise point positioning (PPP). The four ionospheric models studied are the GPS broadcast ionospheric model (GPS-Klo), the BDS (BeiDou Navigation Satellite System) broadcast ionospheric model (BDS-Klo), the BDS ionospheric grid model (BDS-Grid) and the Global Ionosphere Maps (GIM) model. Datasets are collected from 10 stations over one month in 2019. The solar remained calm and the ionosphere was stable during the test period. The experimental results show that for single-frequency SPP, the GIM model achieves the best accuracy, and the positioning accuracy of the BDS-Klo and BDS-Grid model is much better than the solution with GPS-Klo model in the N and U components. For the single-frequency PPP performance, the average convergence time of the ionosphere-constrained PPP is much reduced compared with the traditional PPP approach, where the improvements are of 11.2%, 11.9%, 21.3% and 39.6% in the GPS-Klo-, BDS-Klo-, BDS-Grid- and GIM-constrained GPS + GLONASS + BDS single-frequency PPP solutions, respectively. Furthermore, the positioning accuracy of the BDS-Grid- and GIM-constrained PPP is generally the same as the ionosphere-free combined single-frequency PPP. Through the combination of GPS, GLONASS and BDS, the positioning accuracy and convergence performance for all single-system single-frequency SPP/PPP solutions can be effectively improved.
8
Aggrey, John, and Sunil Bisnath. "Improving GNSS PPP Convergence: The Case of Atmospheric-Constrained, Multi-GNSS PPP-AR." Sensors 19, no. 3 (January 30, 2019): 587. http://dx.doi.org/10.3390/s19030587.
Повний текст джерелаАнотація:
GNSS positioning performance has been shown to improve with the ingestion of data from Global Ionospheric Maps (GIMs) and tropospheric zenith path delays, which are produced by, e.g., the International GNSS Service (IGS). For both dual- and triple-frequency Precise Point Positioning (PPP) processing, the significance of GIM and tropospheric products in processing is not obvious in the quality of the solution after a few hours. However, constraining the atmosphere improves PPP initialization and solution convergence in the first few minutes of processing. The general research question to be answered is whether there is any significant benefit in constraining the atmosphere in multi-frequency PPP? A key related question is: regarding time and position accuracy, how close are we to RTK performance in the age of multi-GNSS PPP-AR? To address these questions, this paper provides insight into the conceptual analyses of atmospheric GNSS PPP constraints. Dual- and triple-frequency scenarios were investigated. Over 60% improvement in convergence time was observed when atmospheric constraints are applied to a dual-frequency multi-GNSS PPP-AR solution. Future work would involve employing the constraints to improve low-cost PPP solutions.
9
Yang, Hao, Shengyue Ji, Duojie Weng, Zhenjie Wang, Kaifei He, and Wu Chen. "Assessment of the Feasibility of PPP-B2b Service for Real-Time Coseismic Displacement Retrieval." Remote Sensing 13, no. 24 (December 9, 2021): 5011. http://dx.doi.org/10.3390/rs13245011.
Повний текст джерелаАнотація:
Traditional coseismic displacement retrieval generally uses real-time kinematic (RTK) and precise point positioning (PPP) services. However, both RTK and real-time PPP need a network link to transmit the corrected data. Although the network link may be interrupted when an earthquake happens, the PPP-B2b service broadcasted by geostationary orbit (GEO) satellites will not be affected. Its service range mainly covers China and the surrounding areas. In this research, the PPP method with PPP-B2b service based on constrained coordinates is proposed and overcomes the limitation of the network link and long convergence time. First, the accuracy of orbits and clock offsets for the PPP-B2b service is evaluated and compared with real-time service (RTS). Then, the simulated experiments are carried out using the PPP method with PPP-B2b service based on constrained coordinates, which tests the accuracy by calculating the coordinate displacement of the measurement station. The results show that the accuracy of PPP-B2b orbits in the radial direction is within 0.1 m. Moreover, regarding the accuracy of clock offsets, the PPP-B2b service is no more than 3.5 cm. This validates the feasibility of replacing RTS products with PPP-B2b. In the 15 min simulated experiments, the root mean square (RMS) of horizontal and vertical directions is maintained within 3 cm.
10
Choi, Byung-Kyu, and Hasu Yoon. "Positioning stability improvement with inter-system biases on multi-GNSS PPP." Journal of Applied Geodesy 12, no. 3 (July 26, 2018): 239–48. http://dx.doi.org/10.1515/jag-2018-0005.
Повний текст джерелаАнотація:
Abstract The availability of multiple signals from different Global Navigation Satellite System (GNSS) constellations provides opportunities for improving positioning accuracy and initial convergence time. With dual-frequency observations from the four constellations (GPS, GLONASS, Galileo, and BeiDou), it is possible to investigate combined GNSS precise point positioning (PPP) accuracy and stability. The differences between GNSS systems result in inter-system biases (ISBs). We consider several ISB values such as GPS-GLONASS, GPS-Galileo, and GPS-BeiDou. These biases are compliant with key parameters defined in the multi-GNSS PPP processing. In this study, we present a unified PPP method that sets ISB values as fixed or constant. A comprehensive analysis that includes satellite visibility, position dilution of precision, position accuracy is performed to evaluate a unified PPP method with constrained cut-off elevation angles. Compared to the conventional PPP solutions, our approach shows more stable positioning at a constrained cut-off elevation angle of 50 degrees.
11
Wang, Guangxing, Yadong Bo, Qiang Yu, Min Li, Zhihao Yin, and Yu Chen. "Ionosphere-Constrained Single-Frequency PPP with an Android Smartphone and Assessment of GNSS Observations." Sensors 20, no. 20 (October 20, 2020): 5917. http://dx.doi.org/10.3390/s20205917.
Повний текст джерелаАнотація:
With the development of Global Navigation Satellite System (GNSS) and the opening of Application Programming Interface (API) of Android terminals, the positioning research of Android terminals has attracted the attention of GNSS community. In this paper, three static experiments were conducted to analyze the raw GNSS observations quality and positioning performances of the smartphones. For the two experimental smartphones, the numbers of visible satellites with dual-frequency signals are unstable and not enough for dual-frequency Precise Point Positioning (PPP) processing all through the day. Therefore, the ionosphere-constrained single-frequency PPP model was employed to improve the positioning with the smartphones, and its performance was evaluated and compared with those of the Single Point Positioning (SPP) and the traditional PPP models. The results show that horizontal positioning accuracies of the smartphones with the improved PPP model are better than 1 m, while those with the SPP and the traditional PPP models are about 2 m.
12
Sheng, Chuanzhen, Xingli Gan, Baoguo Yu, and Jingkui Zhang. "Precise Point Positioning Algorithm for Pseudolite Combined with GNSS in a Constrained Observation Environment." Sensors 20, no. 4 (February 18, 2020): 1120. http://dx.doi.org/10.3390/s20041120.
Повний текст джерелаАнотація:
In urban canyon environments, Global Navigation Satellite System (GNSS) satellites are heavily obstructed with frequent rise and fall and severe multi-path errors induced by signal reflection, making it difficult to acquire precise, continuous, and reliable positioning information. To meet imperative demands for high-precision positioning of public users in complex environments, like urban canyons, and to solve the problems for GNSS/pseudolite positioning under these circumstances, the Global Navigation Satellite System (GNSS) Precision Point Positioning (PPP) algorithm combined with a pseudolite (PLS) was introduced. The former problems with the pseudolite PPP technique with distributed pseudo-satellites, which relies heavily on known points for initiation and prerequisite for previous high-precision time synchronization, were solved by means of a real-time equivalent clock error estimation algorithm, ambiguity fixing, and validation method. Experiments based on a low-cost receiver were performed, and the results show that in a weak obstructed environment with low-density building where the number of GNSS satellites was greater than seven, the accuracy of pseudolite/GNSS PPP with fixed ambiguity was better than 0.15 m; when there were less than four GNSS satellites in severely obstructed circumstances, it was impossible to obtain position by GNSS alone, but with the support of a pseudolite, the accuracy of PPP was able to be better than 0.3 m. Even without GNSS, the accuracy of PPP could be better than 0.5 m with only four pseudolites. The pseudolite/GNSS PPP algorithm presented in this paper can effectively improve availability with less GNSS or even without GNSS in constrained environments, like urban canyons in cities.
13
Mahani, Iris, Rizal Z. Tamin, Rani G. Pradoto, Meifrinaldi, Putri N. K. Whardani, Yongki A. Tanne,, and Kevin A. Hartono. "A STUDY ON THE APPLICATION OF AVAILABILITY PAYMENT SCHEME FOR URBAN INFRASTRUCTURE IN INDONESIA." International Journal of Education and Social Science Research 05, no. 05 (2022): 91–104. http://dx.doi.org/10.37500/ijessr.2022.5506.
Повний текст джерелаАнотація:
The Government of Indonesia encourages the implementation of central and regional infrastructure through Public Private Patnership (PPP) which is regulated by Presidential Regulation no. 30/2015. One of the financing schemes in PPPs is the availability payment (AP), namely periodic payments by the Regional Head to the Implementing Business Entity for the availability of infrastructure services in accordance with the quality and/or criteria as determined by the PPP Agreement (Minister of Finance Regulation No. 260/PMK.08/2016). The AP scheme can be an alternative for PPP projects that are not feasible in terms of user payments because they do not depend on demand. AP is considered still difficult to implement in Indonesian PPPs because it is constrained by various things that need to be evaluated. Through a descriptive narrative approach based on literature review and case surveys, this research analyzes the keys to success, constraints, and recommendations for implementing AP in urban infrastructure in Indonesia. Case studies were conducted on several regional PPP projects in 8 districts/cities in Indonesia that use the AP and user payment schemes, where projects will be compared and evaluated based on the keys to the success of the AP to map constraints and their mitigation. The identification results obtained 13 AP success criteria which are grouped into regulation, institution, and business process aspects. The failure of AP compared to user payments in regional PPP projects is caused by the absence of regional PPP implementation and technical guidelines, the absence of approval from the DPRD and weak coordination with the regional government, the immature experience and preparation of the regional government, and the unpreparedness of regional PPP institutions. The recommendations proposed are the implementation of socialization of PPPs in the regions by the central government, increased coordination between the Regional Government and the DPRD, mature and complete preparation of regional PPP projects, and the implementation of regional PPP capacity building in improving the experience of regional governments.
14
Chu, Feng-Yu, and Yin-Wei Chen. "Monitoring Structural Displacements on a Wall with Five-Constellation Precise Point Positioning: A Position-Constrained Method and the Performance Analyses." Remote Sensing 15, no. 5 (February 27, 2023): 1314. http://dx.doi.org/10.3390/rs15051314.
Повний текст джерелаАнотація:
The global navigation satellite system (GNSS) precise point positioning (PPP) technique has been commonly applied to structural displacement monitoring. Considering the sheltering effect, GNSS receivers are regularly mounted on the top of a structure, but the structure is often not a rigid body; therefore, the receiver should also be mounted on the wall of the structure. Combining five constellations, GNSS can effectively reduce the sheltering effect. Therefore, this study attempts to apply the five-constellation PPP technique to monitor structural long-term displacements on the wall (SLDW) and structural vibrational displacements on the wall (SVDW) and then analyze their performance. Two novel methods are proposed in monitoring SVDW. Firstly, semi-generated measurements are designed to generate pseudo-environments with vibrations for the receiver. Therefore, additional instruments are not necessary to generate vibrations. Secondly, to further reduce the sheltering effect, a position-constrained PPP (PCPPP) model is developed. Formal performance analyses are presented in this study, and the results show that using the five-constellation PPP to monitor SLDW and SVDW in the horizontal direction is possible as long as the sheltering effect over the half sky of the receiver is not severe. In monitoring SVDW, the PCPPP model can perform better than the classical PPP model and be successful in the horizontal direction when the condition of elevation cutoff is given as high as 50°. For Asia-Pacific mid-low-latitude regions, the global positioning system (GPS) and BeiDou system (BDS) are important to maintain the availability of monitoring SVDW.
15
Baxter, David, and Carter B. Casady. "A Coronavirus (COVID-19) Triage Framework for (Sub)National Public–Private Partnership (PPP) Programs." Sustainability 12, no. 13 (June 29, 2020): 5253. http://dx.doi.org/10.3390/su12135253.
Повний текст джерелаАнотація:
Around the world, countries are struggling to address the immediate and long-term impacts of the novel coronavirus (COVID-19) pandemic on their (sub)national public–private partnership (PPP) programs. Burdened with the real possibility of widespread project failures and constrained budgets, governments are searching for ways to prioritize projects in need of relief and bolster post-pandemic recovery plans. To meet this need, this article conceptualizes a triage system for PPP programs based on five categories: (1) projects without a need for economic stimulus (blue); (2) projects experiencing minor economic/financial losses (green); (3) projects needing temporary/stop-gap support or restructuring (yellow); (4) projects unable to survive without significant economic relief (red); and (5) projects that cannot survive, even with government intervention (black). This research also stresses the importance of launching and sustaining a crisis command center to support PPP triage decisions and encourages PPP stakeholders to collectively craft win–win solutions for post-pandemic recovery efforts.
16
Baporikar, Neeta. "Dynamics in Implementation of Public Private Partnerships." International Journal of Political Activism and Engagement 7, no. 1 (January 2020): 23–53. http://dx.doi.org/10.4018/ijpae.2020010102.
Повний текст джерелаАнотація:
Governments all over the world play a crucial role in the development of infrastructure and the provision of basic services to the citizens. With increasing population, urbanization, other developmental needs, the governments' ability to address public needs through traditional means is severely constrained. Due to this, new approaches and forms are being sought after and one such is through contractual agreements with the private sector commonly referred to as a public-private partnership (PPP). A PPP is a contractual agreement involving the private sector in the delivery of public services. PPP formations are effected by government support, economic uncertainties, market readiness, and organizational factors. Adopting a mixed methods approach, the primary data was collected through questionnaires, interviews, and secondary data from published reports and documents the objective was to explore the dynamics in the implementation of PPP agreements with focus on Namibia and enhance the knowledge to enable the government and private entities in dealing well with these factors.
17
Chen, Junping, Ahao Wang, Yize Zhang, Jianhua Zhou, and Chao Yu. "BDS Satellite-Based Augmentation Service Correction Parameters and Performance Assessment." Remote Sensing 12, no. 5 (February 27, 2020): 766. http://dx.doi.org/10.3390/rs12050766.
Повний текст джерелаАнотація:
BDS (Beidou Navigation Satellite System) integrates the legacy PNT (Positioning, Navigation, Timing) service and the authorized SBAS (Satellite-Based Augmentation Services) service. To support the requirement of decimeter-level positioning, four types of differential corrections are developed in the BDS SBAS, including the State Space Representation (SSR)-based satellite orbit/clock corrections, the Observation Space Representation (OSR)-based ionospheric grid corrections, and the partition comprehensive corrections. In this study, we summarize the features of these differential corrections, including their definition and usages. The function model of precise point positioning (PPP) for dual- and single-frequency users using the four types of BDS SBAS corrections are proposed. Datasets are collected from 34 stations over one month in 2019, and PPP is performed for all the datasets. Results show that the root mean square (RMS) of the positioning errors for static/kinematic dual-frequency (DF) PPP are of 12 cm/16 cm in horizontal and 18 cm/20 cm in vertical component, while for single-frequency (SF) PPP are of 14 cm/32 cm and 22 cm/40 cm, respectively. With regard to the convergence performance, the horizontal and vertical positioning errors of kinematic DF-PPP can converge to 0.5 m in less than 15 min and 20 min, respectively. As for the kinematic SF-PPP, it could converge to 0.8 m in horizontal and 1.0 m in vertical within 30 min, where the ionosphere-constrained PPP performs better than the UofC PPP approach, owing to the contribution of the ionospheric grid corrections.
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Zhou, Xuan, Dan Liu, and Chuanbin Yin. "Research on Public Rental Housing PPP Project Launching Dilemmas with Dynamic Evolutionary Game." Advances in Civil Engineering 2021 (December 14, 2021): 1–15. http://dx.doi.org/10.1155/2021/1805874.
Повний текст джерелаАнотація:
The public housing PPP projects have encountered a cold reception from the government, which constrained solving the urban housing problem. This paper builds a dynamic game model under incomplete contract conditions, analyzes the key factors affecting the signing of PPP contracts by dynamic evolutionary game analysis, and verifies these factors by simulation. The results show that fiscal spending smoothing, risk transfer, and government performance can promote government to adopt cooperation strategy. Expected project benefits and government performance incentives can promote private capital to adopt cooperation strategy. Changes in transaction cost have a significant impact on the decision of cooperation strategy.
19
Li, Yanjie, Changsheng Cai, and Zhenyu Xu. "A Combined Elevation Angle and C/N0 Weighting Method for GNSS PPP on Xiaomi MI8 Smartphones." Sensors 22, no. 7 (April 6, 2022): 2804. http://dx.doi.org/10.3390/s22072804.
Повний текст джерелаАнотація:
Traditionally, an elevation-angle-dependent weighting method is usually used for Global Navigation Satellite System (GNSS) positioning with a geodetic receiver. As smartphones adopt linearly polarized antenna and low-cost GNSS chips, different GNSS observation properties are exhibited. As a result, a carrier-to-noise ratio (C/N0)-dependent weighting method is mostly used for smartphone-based GNSS positioning. However, the C/N0 is subject to the effects of the observation environment, resulting in an unstable observation weight. In this study, we propose a combined elevation angle and C/N0 weighting method for smartphone-based GNSS precise point positioning (PPP) by normalizing the C/N0-derived variances to the scale of the elevation-angle-derived variances. The proposed weighting method is validated in two kinematic PPP tests with different satellite visibility conditions. Compared with the elevation-angle-only and C/N0-only weighting methods, the combined weighting method can effectively enhance the smartphone-based PPP accuracy in a three-dimensional position by 22.7% and 24.2% in an open-sky area, and by 52.0% and 26.0% in a constrained visibility area, respectively.
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Song, Chuanfeng, Hongyang Ma, Huizhong Zhu, Bo Wu, and Nan Shen. "External Tropospheric Corrections by Using Kriging Interpolation for Improving PPP-RTK Positioning Solutions." Remote Sensing 14, no. 15 (August 4, 2022): 3747. http://dx.doi.org/10.3390/rs14153747.
Повний текст джерелаАнотація:
With the availability of satellite carrier-phase delay corrections provided by a reference network or the International GNSS Service (IGS), the integer ambiguity resolution for a single receiver can be successfully achieved, which is the so-called PPP-RTK concept. Although PPP-RTK can significantly shorten the convergence time, it is still worthwhile to further investigate fast and high-precision GNSS parameter estimation to improve efficiency and productivity. In order to fully exploit the potential of GNSS for positioning applications, we herein introduce external troposphere corrections as constrained pseudo observables to the undifferenced and uncombined PPP-RTK model. Since the uncertainties of the corrections are considered in the data processing, the PPP-RTK model with the weighted tropospheric corrections is referred to as the tropospheric-weighted model. Kriging interpolation is applied to generate the tropospheric corrections, as well as the corresponding variances. The quality of the tropospheric-weighted model is assessed by the positioning Root Mean Square (RMS) errors and the convergence time to reach a 10 cm accuracy. The 90% 3D convergence time of the kinematic positioning mode of the tropospheric-weighted model is 43.5 min with the ambiguity-float solution and 21.5 min with the ambiguity-fixed solution, which are shortened by 4.5 min and 5.5 min as compared to those of the standard PPP-RTK model, respectively. As for the static positioning mode, the 90% 3D convergence time of the tropospheric-weighted model for the ambiguity-float and -fixed solutions is 25.5 min and 15 min, while the 3D convergence time is 31.5 min and 18.5 min for the standard PPP-RTK model, respectively. The results also show that the tropospheric-weighted model can still work well in a 5 cm convergence threshold.
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Semenova, Elena Ivanovna, and Vladimir Gennadievich Novikov. "Using of PPP mechanisms in rural social sphere: domestic and foreign experience." Mezhdunarodnaja jekonomika (The World Economics), no. 11 (November 1, 2020): 46–54. http://dx.doi.org/10.33920/vne-04-2011-05.
Повний текст джерелаАнотація:
The article shows the importance of using the public-private partnership mechanism for the development of the social sphere of the village. Review of PPP implementation by countries G20 showed different legal approaches in PPP implementation, parallel use and concessions, and agreements, application of guaranteed minimum income and risk sharing among participants, use of different PPP support measures. The presented results of the questionnaire indicate the largest use of PPPs in housing and communal services — 272 projects (81.68 %), which is due to the high degree of wear and tear in water and heat supply, in education — 22 projects (6.61 %), mainly the construction of preschool institutions, school repairs, in the field of sports and tourism 14 projects (4.2 %) — the construction of sports grounds and stadiums, sports centers, 10 projects (3 %). Public-private partnership projects in the social sphere of rural areas are less marginal, their financing is associated with significant difficulties due to the heterogeneity of demand, the difficulty of forecasting consumer demand and assessing social effect. The development of public-private partnerships is constrained by the lack of necessary budget funds to ensure the minimum guaranteed income of a private partner, the duration and complexity of maintaining procedures.
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Pandey, D., R. Dwivedi, O. Dikshit, and A. K. Singh. "GPS AND GLONASS COMBINED STATIC PRECISE POINT POSITIONING (PPP)." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B1 (June 3, 2016): 483–88. http://dx.doi.org/10.5194/isprsarchives-xli-b1-483-2016.
Повний текст джерелаАнотація:
With the rapid development of multi-constellation Global Navigation Satellite Systems (GNSSs), satellite navigation is undergoing drastic changes. Presently, more than 70 satellites are already available and nearly 120 more satellites will be available in the coming years after the achievement of complete constellation for all four systems- GPS, GLONASS, Galileo and BeiDou. The significant improvement in terms of satellite visibility, spatial geometry, dilution of precision and accuracy demands the utilization of combining multi-GNSS for Precise Point Positioning (PPP), especially in constrained environments. Currently, PPP is performed based on the processing of only GPS observations. Static and kinematic PPP solutions based on the processing of only GPS observations is limited by the satellite visibility, which is often insufficient for the mountainous and open pit mines areas. One of the easiest options available to enhance the positioning reliability is to integrate GPS and GLONASS observations. This research investigates the efficacy of combining GPS and GLONASS observations for achieving static PPP solution and its sensitivity to different processing methodology. Two static PPP solutions, namely standalone GPS and combined GPS-GLONASS solutions are compared. The datasets are processed using the open source GNSS processing environment <i>gLAB</i> 2.2.7 as well as <i>magicGNSS</i> software package. The results reveal that the addition of GLONASS observations improves the static positioning accuracy in comparison with the standalone GPS point positioning. Further, results show that there is an improvement in the three dimensional positioning accuracy. It is also shown that the addition of GLONASS constellation improves the total number of visible satellites by more than 60% which leads to the improvement of satellite geometry represented by Position Dilution of Precision (PDOP) by more than 30%.
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Pandey, D., R. Dwivedi, O. Dikshit, and A. K. Singh. "GPS AND GLONASS COMBINED STATIC PRECISE POINT POSITIONING (PPP)." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B1 (June 3, 2016): 483–88. http://dx.doi.org/10.5194/isprs-archives-xli-b1-483-2016.
Повний текст джерелаАнотація:
With the rapid development of multi-constellation Global Navigation Satellite Systems (GNSSs), satellite navigation is undergoing drastic changes. Presently, more than 70 satellites are already available and nearly 120 more satellites will be available in the coming years after the achievement of complete constellation for all four systems- GPS, GLONASS, Galileo and BeiDou. The significant improvement in terms of satellite visibility, spatial geometry, dilution of precision and accuracy demands the utilization of combining multi-GNSS for Precise Point Positioning (PPP), especially in constrained environments. Currently, PPP is performed based on the processing of only GPS observations. Static and kinematic PPP solutions based on the processing of only GPS observations is limited by the satellite visibility, which is often insufficient for the mountainous and open pit mines areas. One of the easiest options available to enhance the positioning reliability is to integrate GPS and GLONASS observations. This research investigates the efficacy of combining GPS and GLONASS observations for achieving static PPP solution and its sensitivity to different processing methodology. Two static PPP solutions, namely standalone GPS and combined GPS-GLONASS solutions are compared. The datasets are processed using the open source GNSS processing environment <i>gLAB</i> 2.2.7 as well as <i>magicGNSS</i> software package. The results reveal that the addition of GLONASS observations improves the static positioning accuracy in comparison with the standalone GPS point positioning. Further, results show that there is an improvement in the three dimensional positioning accuracy. It is also shown that the addition of GLONASS constellation improves the total number of visible satellites by more than 60% which leads to the improvement of satellite geometry represented by Position Dilution of Precision (PDOP) by more than 30%.
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Zhang, Wenjie, Hongzhen Yang, Chen He, Zhiqiang Wang, Weiping Shao, Yongfeng Zhang, and Jing Wang. "Initial Performance Evaluation of Precise Point Positioning with Triple-Frequency Observations from BDS-2 and BDS-3 Satellites." Journal of Navigation 73, no. 4 (February 20, 2020): 763–75. http://dx.doi.org/10.1017/s0373463319000754.
Повний текст джерелаАнотація:
This paper presents an investigation of the precise point positioning (PPP) performance of a combined solution from BDS-2 and BDS-3 satellites. To simultaneously process different BDS signal observations, i.e., B1/B1C, B2/B2a and B3C, undifferenced and uncombined observations with ionosphere delay constrained by the deterministic plus stochastic ionosphere model are used in the basic model. Special attention is paid to code bias and receiver clock parameters in the derivation of the observation model. The analysis is carried out using more than one-month data for BDS-2 and BDS-3 collected at the CANB, DWIN, KNDY and PETH stations in the Asia-Pacific region. The results suggest that compared with BDS-2 alone, the BDS-2 and BDS-3 solution provides significantly more accurate PPP, with increases of 28%, 21% and 5% in the up, north and east directions, respectively. In addition, the average root mean square error decreases to 0·21, 0·13 and 0·16 m for the three directions. Furthermore, the PPP convergence time for BDS-2 and BDS-3 is about 1·5 h and less than 1 h for the horizontal and vertical components, respectively, whereas that for BDS-2 alone is about 2·3 h for both directions.
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Cao, Xinyun, Fei Shen, Yulong Ge, Chao Liu, and Shoujian Zhang. "Inter-frequency code bias handling and estimation for multi-frequency BeiDou-3/Galileo uncombined precise point positioning." Measurement Science and Technology 33, no. 1 (November 17, 2021): 015012. http://dx.doi.org/10.1088/1361-6501/ac3198.
Повний текст джерелаАнотація:
Abstract The development of a global navigation satellite system (GNSS) with multi-frequency signals brings new opportunities for providing high-quality positioning, navigation and timing (PNT) services. Proper inter-frequency code bias (IFB) handling is a prerequisite for multi-frequency uncombined precise point positioning (UC-PPP) to ensure reliable and accurate PNT services. This work focuses on analyzing the mathematical representation of estimated parameters, as well as the relationship between different multi-frequency UC-PPP models, caused by whether to correct the inter-frequency satellite differential code bias (DCB) or the external ionosphere. Multi-GNSS experiment (MGEX) network stations tracking Galileo E1/E5a/E5b/E6/E5ab and BeiDou-3 (BDS-3) B1I/B3I/B1C/B2a signals were used to investigate the positioning performance and parameter estimations of three multi-frequency UC-PPP models. The results show that the loosely constrained ionosphere will make the estimated ionosphere and DCB/IFB parameters unable to effectively separate due to their high linear dependence. The 3D positioning accuracy of UC-PPP using Galileo five-frequency, BDS-3 four-frequency and Galileo/BDS-3 multi-frequency signals in static mode is 1.76, 2.36 and 1.39 cm, while the corresponding accuracy in kinematic mode is 6.40, 7.08 and 4.16 cm, respectively. The consistency of Galileo IFBs with respect to the MGEX DCB files is rather good, and the probability of deviations within 0.3 ns is 96.58%. Compared to Galileo, the agreement of the BDS-3 IFBs with respect to the reference values is worse, with 92.69% of them within 1 ns.
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Yang, Fuxin, Lin Zhao, Liang Li, Jianhua Cheng, and Jie Zhang. "Ionosphere-Constrained Triple-Frequency Cycle Slip Fixing Method for the Rapid Re-Initialization of PPP." Sensors 19, no. 1 (December 31, 2018): 117. http://dx.doi.org/10.3390/s19010117.
Повний текст джерелаАнотація:
The re-initialization of precise point positioning (PPP) can be avoided by cycle slip detection and correction. Ionospheric delay is critical for cycle slip detection and correction, especially for a long data gap. The frequency diversity from GNSS modernization provides the potential for mitigating the impact of ionospheric delay on cycle slip detection and correction. The proposed method constructs the extra-wide lane (EWL), the wide lane (WL), and the narrow lane (NL) epoch-differenced linear combinations based on the ionosphere constrain criterion, so as to determine the undifferenced cycle slips from the cascading ambiguity resolution. The experiment results show that the cycle slips can be fixed correctly even though cycle slips occur in all the available carrier phase observations, and the 3 min data gaps can be merged without high precision positioning continuity loss. The kinematic experiment shows that the instantaneous re-initialization can be achieved with the proposed method.
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Gao, Zhouzheng, Maorong Ge, Wenbin Shen, Hongping Zhang, and Xiaoji Niu. "Ionospheric and receiver DCB-constrained multi-GNSS single-frequency PPP integrated with MEMS inertial measurements." Journal of Geodesy 91, no. 11 (May 18, 2017): 1351–66. http://dx.doi.org/10.1007/s00190-017-1029-7.
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Liu, Yuhao, Xiaohan Sun, Guoquan Wang, Michael J. Turco, Gonzalo Agudelo, Yan Bao, Ruibin Zhao, and Shuilong Shen. "Current Activity of the Long Point Fault in Houston, Texas Constrained by Continuous GPS Measurements (2013–2018)." Remote Sensing 11, no. 10 (May 22, 2019): 1213. http://dx.doi.org/10.3390/rs11101213.
Повний текст джерелаАнотація:
The Long Point Fault is one of the most active urban faults in Houston, Texas, which belong to a complex system of normal growth faults along the Texas Gulf Coast. To assess the activity of the Long Point Fault, a GPS array with 12 permanent stations was installed along the two sides of the 16-km-long fault scarp in 2013. GPS datasets were processed with the Precise Point Positioning (PPP) and Double-Difference (DD) methods. The daily PPP solutions with respect to the International Global Navigation Satellite System (GNSS) Reference Frame 2014 (IGS14) were converted to the Stable Houston Reference Frame (Houston16). The six-year continuous GPS observations indicate that the Long Point Fault is currently inactive, with the rates of down-dip-slip and along-strike-slip being below 1 mm/year. The Long Point Fault area is experiencing moderate subsidence varying from 5 to 11 mm/year and a coherent horizontal movement towards the northwest at a rate of approximately 2 to 4 mm/year. The horizontal movement is induced by the subsidence bowl that has been developing since the 1980s in the Jersey Village area. Current surficial damages in the Long Point Fault area are more likely caused by ongoing uneven subsidence and its induced horizontal strains, as well as the significant seasonal ground deformation, rather than deep-seated or tectonic-controlled fault movements. The results from this study suggest a cause-and-effect relationship between groundwater withdrawals and local faulting, which is pertinent to plans for future urban development, use of groundwater resources, and minimization of urban geological hazards.
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Böhm, Michael C., та Johannes Schütt. "Quantum Constraints in π Systems: The Role of the Pauli Antisymmetry Principle for π Electronic Properties". Zeitschrift für Naturforschung A 52, № 10 (1 жовтня 1997): 717–26. http://dx.doi.org/10.1515/zna-1997-1006.
Повний текст джерелаАнотація:
Abstract It is demonstrated that the Pauli antisymmetry principle (PAP) is without influence in the π electron subspace of polyenes and (4n + 2) annulenes (n = 0, 1, 2...) as long as the hoppings are restricted to nearest-neighbour centers. Here the π electrons behave like a hard core bosonic (hcb) ensemble where fermionic on-site and bosonic intersite properties are combined. In 4n and (2n + 1) annulenes (n = 1,2, 3...) π electron jumps between the first and last ring atom lead to a Pauli antisymmetry-based destabilization. The second quantum constraint in fermionic systems is the Pauli exclusion principle (PEP). In the many-electron basis adopted in the present work it is possible to treat the PAP and PEP as two decoupled constraints. The electronic destabilization due to the PEP is enhanced with increasing size of the system. The influence of the PAP and PEP on the π electrons is discussed in terms of π energies and charge fluctuations. The model Hamiltonians adopted are of the Hückel molecular orbital (HMO) and Pariser-Parr-Pople (PPP) type. We suggest quantum statistical definitions of the quantities "aromaticity" and "antiaromaticity", qualitative descriptors which are widely employed in the chemical literature.
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Tjendani, Hanie Teki, Risma Marleno, Hendry Hendry, and Iwan Subiyantoro. "Risk Assessment of Feasibility Study for Toll Road X - Y with Public Private Partnership Scheme." UKaRsT 5, no. 1 (April 3, 2021): 142. http://dx.doi.org/10.30737/ukarst.v5i1.1558.
Повний текст джерелаАнотація:
The PPP scheme is carried out in Indonesia to procure public infrastructure but is constrained by the government's limited funds. Risk assessment is very important for investors to do to find out the uncertainty that can occur in investing their funds in infrastructure. This study aims to assess the Risk of Feasibility on the X - Y Toll Road, where the location is part of the East Java Province economic development acceleration program by President Regulation number 80 of 2019. The assessment carried out includes risk analysis in the pre-construction, construction, and post-construction stage. The data used are primary data and secondary data. From the assessment results, it was found that most of the assessment points were categorized as medium risk, and there was a little high risk. Still, this project is very profitable because it will be able to synergize with the previously planned infrastructure. The X-Y toll road is still possible by paying attention to risk factors and complying with risk mitigation efforts. The toll road procurement scheme with Public-Private Partnership (PPP) already has a robust legal rule and has been guaranteed in terms of security, and this scheme is very potential to be implemented.
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Zhang, Hongping, Zhouzheng Gao, Maorong Ge, Xiaoji Niu, Ling Huang, Rui Tu, and Xingxing Li. "On the Convergence of Ionospheric Constrained Precise Point Positioning (IC-PPP) Based on Undifferential Uncombined Raw GNSS Observations." Sensors 13, no. 11 (November 18, 2013): 15708–25. http://dx.doi.org/10.3390/s131115708.
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Tshombe, Lukamba Muhiya, Thekiso Molokwane, Alex Nduhura, and Innocent Nuwagaba. "An Analysis of Public-Private Partnerships in East Africa." Research in World Economy 11, no. 5 (September 3, 2020): 152. http://dx.doi.org/10.5430/rwe.v11n5p152.
Повний текст джерелаАнотація:
The impact of the implementation of public-private partnerships (PPPs) in the Sub-Saharan African region on infrastructure and services is becoming increasingly perceptible. A considerable number of African countries have embraced PPPs as a mechanism to finance large projects due to a constrained fiscus. At present, many financial institutions, such as the World Bank, the International Monetary Fund and the African Development Bank, which finance some of the projects, have established a department or unit that mainly focuses on infrastructure development in developing countries. The private sector in Africa is equally seen as a significant partner in the development of infrastructure. African governments need to tap into private capital to invest in infrastructure projects. This scientific discussion provides an analysis of PPPs in the East African region. This article selected a number of countries to illustrate PPP projects in the sub-region. The analysis of this study illustrates that the East African region represents unique and valuable public-private partnership lessons in different countries. This study also traces the origins of PPPs to more than a century ago where developed countries completed some of their projects using the same arrangement. This paper further demonstrates that the application of PPPs is always characterised by three factors, namely a country, a sector and a project. Experts in the field often refer to these elements as layers, which usually precede any successful PPP.
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Yue, Caiya, Yamin Dang, Shuqiang Xue, Hu Wang, Shouzhou Gu, and Changhui Xu. "A New Optimal Subset Selection Method of Partial Ambiguity Resolution for Precise Point Positioning." Remote Sensing 14, no. 19 (September 27, 2022): 4819. http://dx.doi.org/10.3390/rs14194819.
Повний текст джерелаАнотація:
Rapid and accurate ambiguity resolution is the core of high-precision precise point positioning (PPP) data processing. However, the ambiguity parameters in PPP observation models are easily affected by atmospheric residual and gross errors, which lead to the probability of successfully fixing decreases and computational burden increases in full ambiguity resolution. Therefore, an increasing number of partial ambiguity resolution (PAR) strategies have been proposed. The selection of the optimal subset of PAR is crucial in this method. The traditional optimal subset selection method of PAR commonly leads to a single judgment criterion and weakened geometric configuration strength because the satellites with low elevation angles are often easily eliminated during the optimal subset selection. In this paper, a multi-factor constrained optimal subset selection method for PAR was proposed, which incorporates the ambiguity variance, the ambiguity dilution of precision (ADOP), satellite position dilution of precision (PDOP) and ratio test values. In order to verify the feasibility of the proposed optimal subset selection method, PAR tests under two schemes were performed for GPS/Galileo based on the static observation data of 15 Multi-GNSS Experiment (MGEX) tracking stations. The results show that, compared with the ambiguity variance sorting method, the proposed subset selection method can further improve the accuracy of the coordinate solution and the strength of geometric figure positioning. The average root mean square of the coordinate residuals is found to decrease by about 12.90%, 6.83% and 9.39% in the eastern, northern and vertical directions, respectively. The increase in the fixed epoch rate ranged from 0.87% to 33.33%, with an average of about 8.71%.
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Mulyo, Jangkung Handoyo, Sugiyarto Sugiyarto, and Arif Wahyu Widada. "KETAHANAN DAN KEMANDIRIAN PANGAN RUMAH TANGGA TANI DAERAH MARGINAL DI KABUPATEN BOJONEGORO." Agro Ekonomi 26, no. 2 (December 21, 2016): 121. http://dx.doi.org/10.22146/agroekonomi.17265.
Повний текст джерелаАнотація:
Food security and food self-sufficiency at household level are much determined by their farm production. Meanwhile, some areas considered as the marginal area are constrained by limited support of natural resources. Thus, many households lived in marginal area will face food insecurity. This study aimed to understand the households’ food security level, both measured by using the Energy Sufficiency Score (AKE) and the Food Expenditure Share (PPP). Furthermore, this study also tries to identify the food self-sufficiency level among rural marginal household in Bojonegoro Regency. The result of study shows that there is a wide disparity among rural household in the food/energy intake, this is shown by the average level of food/energy intake level that is considered high (87%), meanwhile there is 53% of the households categorized as the food insecure household. Based on the Food Expenditure Share level, most of the households are categorized as food secure households. The food self-sufficiency, particularly rice, have been attained.
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Prajapati, Jagruti, Jaydip Oza, B. B. Patel, and Sunil R. Avashia. "Assessment of glycaemic control among self-reported cases of diabetes: an observation of a PPP model project." International Journal Of Community Medicine And Public Health 5, no. 2 (January 24, 2018): 611. http://dx.doi.org/10.18203/2394-6040.ijcmph20180237.
Повний текст джерелаАнотація:
Background: Sociodemographic determinants of diabetes such as age, sex and socioeconomic status play a major role in diabetes outcome. It was necessary to design a research project to address this. The aim of this study is to determine the prevalence of diabetes and its sociodemographic factors such as age, gender, residential area, economic status and a level of education in the project districts. Methods: The cross sectional study was carried out in the project districts named Ahmedabad, Dahod and Valsad. Urban, rural and tribal population are above 30 years of age from different districts were covered to collect data on socio economic back ground and status of diabetes. Random blood sugar was measured by glucometer and glycosylated haemoglobin (HbA1c) by the HbA1c analyzer. Results: Proportion of male and female participants were near to equal. Percentage of self reported cases of diabetes (including controlled and uncontrolled) was 14.07% in urban areas while it was 5.24% in rural areas. Pre diabetes detection rate was more in rural area. During screening 11.83% of pre diabetes cases were identified. Difference between controlled and uncontrolled diabetes among illiterate and literate groups was statistically not significant. Conclusions: This preliminary observational study included more than 51000 participants visiting primary and community health centres from three districts of Gujarat. The public private partnership model helped in systematic approach towards screening and data collection. The study reported prediabetes cases higher than global prevalence. More controlled studies are required to define the mandatory screening protocol in resource constrained settings.
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Chen, Junping, Jungang Wang, Ahao Wang, Junsheng Ding, and Yize Zhang. "SHAtropE—A Regional Gridded ZTD Model for China and the Surrounding Areas." Remote Sensing 12, no. 1 (January 2, 2020): 165. http://dx.doi.org/10.3390/rs12010165.
Повний текст джерелаАнотація:
A regional zenith tropospheric delay (ZTD) empirical model, referred to as SHAtropE (SHanghai Astronomical observatory tropospheric delay model—Extended), is developed and provides tropospheric propagation delay corrections for users in China and the surrounding areas with improved accuracy. The SHAtropE model was developed based on the ZTD time series of the continuous GNSS sites from the Crustal Movement Observation Network of China (CMONOC) and GNSS sites of surrounding areas. It combines the exponential and periodical functions and is provided as regional grids with a resolution of 2.5° × 2.0° in longitude and latitude. At each grid point, the exponential function converts the ZTD from the site height to the ellipsoid, and the periodical terms, including both annual and semi-annual periods, describe ZTD’s temporal variation. Moreover, SHAtropE also provides the predicted ZTD uncertainty, which is valuable in Precise Point Positioning (PPP) with ZTD being constrained for faster convergence. The data of 310 GNSS sites over 7 years were used to validate the new model. Results show that the SHAtropE ZTD has an accuracy of 3.5 cm in root mean square (RMS) quantity, which has a mean improvement of 35.2% and 5.4% over the UNB3m (5.4 cm) and GPT3 (3.7 cm) models, respectively. The predicted uncertainty of SHAtropE ZTD shows seasonal variations, where the values are larger in summer than in winter. By applying the SHAtropE model in the static PPP, the convergence time of GPS-only and BDS-only solutions are reduced by 8.1% and 14.5% respectively compared to the UNB3m model, and the reductions are 6.9% and 11.2% respectively for the GPT3 model. As no meteorological data are required for the implementation of the model, the SHAtropE could thus be a refined tropospheric model for GNSS users in mainland China and the surrounding areas. The method of modeling the ZTD uncertainty can also be used in further global tropospheric delay modeling.
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Hafid, Zulham, Amiruddin Akbar Fisu, Windra Priatna Humang, and Rakhmawati Natsir. "Application of The PPP Scheme on The Tourism-Transportation, Case Study : The Concept Of Palopo City Tourism." PENA TEKNIK: Jurnal Ilmiah Ilmu-Ilmu Teknik 7, no. 1 (March 7, 2022): 32. http://dx.doi.org/10.51557/pt_jiit.v7i1.1119.
Повний текст джерелаАнотація:
The stipulation of the Palopo City Regional Tourism Development Master Plan 2021 – 2025 makes the Palopo City tourism sector quite optimistic after the beginning of the pandemic. Until 2030, Palopo City targets 250,000 domestic tourists and 1800 foreign tourists. The tourism potential of Palopo City, especially in urban areas is quite promising with the construction of a culinary center and souvenirs, public space activities, and the development of culinary businesses. These potentials must be supported by adequate facilities and infrastructure, including accessibility. Meanwhile, public transportation in Palopo City is considered inadequate and not integrated with each other. The concept of Palopo City Tourism offers the integration of tourism activities in the urban areas of the city of Palopo by providing integrated tourism transportation modes, equipped with supporting infrastructure such as bus stops. However, the implementation of the concept will be constrained by funding problems given the limited regional finances and the demand to prioritize sectors that are more strategic than tourism. This paper will see how the implementation of the PPP scheme in the tourism sector, especially in the transportation aspect, namely in the concept of Palopo City Tourism, both in development, operation and potential benefits. From the results of the analysis of movement patterns and the location of tourist objects, 3 optimal routes were chosen that could accommodate the movement of tourists, namely the southern route, western route and northern route. From the results of the analysis of infrastructure needs, it is necessary to develop infrastructure in the form of shelters and pedestrian paths and their accessories at tourist attraction points and several commercial areas. In addition, several PPP financing schemes are also proposed which are considered suitable for the City Tour Palopo concept, including Concessions and Affermage/Lease schemes, such as Service Contracts and Management Contracts, Design-Build-Finance-Operate/Maintain (DBFO, DBFM or DBFO). /M), Build-Own-Lease-Transfer (BOLT).
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Wang, Ren, Jingxiang Gao, Yifei Yao, Peng Sun, and Moufeng Wan. "Assessment of the Algorithm for Single Frequency Precise Point Positioning at Different Latitudes and with Distinct Magnetic Storm Conditions." Applied Sciences 10, no. 7 (March 26, 2020): 2268. http://dx.doi.org/10.3390/app10072268.
Повний текст джерелаАнотація:
This paper analyzes the convergence time and the root mean square (RMS) error of single frequency (SF) precise point positioning (PPP) in the ionospheric-constrained (TIC1) and troposphere- and ionospheric-constrained (TIC2) conditions, when the stations are at a low latitude, mid-latitude, and high latitude area during the period of a magnetic storm (MS) and a non-magnetic storm (NMS). In this paper, 375 IGS (international global navigation satellite system (GNSS) service) stations were selected from all over the world for 30 days in September 2017. The 24 hour daily observations were split for each station into 8 data sets of 3 hours each, so that a total of 90,000 tests were carried out. After statistical analysis, it was concluded that: during the MS period, the percentage of TIC2 shortened compared to the TIC1 convergence time, and it was by at least 3.9%, 3.0%, and 9.3% when the station was at global, low latitude, and high latitude areas, respectively. According to the statistical analysis, during the NMS period the convergence time was shortened about at least 12.8%, 11.0%, and 30.0% with respect to the stations in the MS period at global, low, and high latitude areas, respectively. If the station was located in the mid-latitude region, the convergence time was not shortened in some modes. The ionospheric activity in the mid-latitude region was less than that in the low-latitude region, while there were more stations in the mid-latitude region, and the precision of the global ionospheric maps (GIMs) and zenith tropospheric delay (ZTD) products were also slightly higher. Overall, TIC1 and TIC2 have a greater impact on convergence time, but have less impact on positioning accuracy, and only have a greater impact in different environments during the MS and NMS periods.
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Hordyniec, Paweł, Jan Kapłon, Witold Rohm, and Maciej Kryza. "Residuals of Tropospheric Delays from GNSS Data and Ray-Tracing as a Potential Indicator of Rain and Clouds." Remote Sensing 10, no. 12 (November 30, 2018): 1917. http://dx.doi.org/10.3390/rs10121917.
Повний текст джерелаАнотація:
The Global Navigation Satellite System (GNSS) is commonly recognized by its all-weather capability. However, observations depend on atmospheric conditions which requires the induced tropospheric delay to be estimated as an unknown parameter. In the following study, we investigate the impact of intense weather events on GNSS estimates. GNSS slant total delays (STD) in Precise Point Positioning technique (PPP) strategy were calculated for stations in southwest Poland in a 56 days period covering several heavy precipitation cases. The corresponding delays retrieved from Weather Research and Forecasting (WRF) model by a ray-tracing technique considered only gaseous parts of the atmosphere. The discrepancies are correlated with rain rates and cloud type products from remote sensing platforms. Positive correlation is found as well as GNSS estimates tend to be systematically larger than modeled delays. Mean differences mapped to the zenith direction are showed to vary between 10 mm and 30 mm. The magnitude of discrepancies follows the intensity of phenomena, especially for severe weather events. Results suggest that effects induced by commonly neglected liquid and solid water terms in the troposphere modeling should be considered in precise GNSS applications for the atmosphere monitoring. The state-of-art functional model applied in GNSS processing strategies shows certain deficits. Estimated tropospheric delays with gradients and post-fit residuals could be replaced by a loosely constrained solution without loss of quality.
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Wu, Horng‐Huei, Ching‐Piao Chen, Chih‐Hung Tsai, and Kuo‐Wei Huang. "Research on the Throughput Impact of the Strategic Stabilizing Capacity Constraint Resources by Prolonging Planning Period." Asian Journal on Quality 10, no. 2 (August 21, 2009): 29–42. http://dx.doi.org/10.1108/15982680980001443.
Повний текст джерелаАнотація:
The issue of capacity constraint resources (CCR) or bottlenecks wandering in product mix decision by applying Theory of Constraints (TOC) management philosophy has been mentioned and demonstrated in several papers. In this study, the effect for prolonging the planning period (PPP) so as to stabilize the CCR is investigated. The results show that the effect for PPP alternative will be positive or negative which is depending on the environment condition. However, a majority cases which have positive effect for PPP alternative can be recognized prior knowing the marketing demand, which is significant in the real application.
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Edakkandi Meethal, Reji. "Towards building a skill based society in India." International Journal of Sociology and Social Policy 34, no. 3/4 (April 8, 2014): 181–95. http://dx.doi.org/10.1108/ijssp-01-2013-0016.
Повний текст джерелаАнотація:
Purpose – The purpose of this paper is to examine whether public-private partnerships (PPPs) in skill building and employability training have or were able to contribute making quality skill training and employability services accessible at affordable prices to the poor as well as marginalized sections of the population in India. Design/methodology/approach – The paper adopts a case study approach. The key sections of the paper review the existing vocational and skill building ecosystem in the country and the recent policy initiatives. The other sections of the paper describes the business model of Gram Tarang, highlighting their strategies of mobilization of candidates, training infrastructure, curriculum and key aspects of partnership with industry and employers, strategies for scaling up and sustainability. Findings – Review of past experience in skill building and employability training in the country suggests that neither the public nor the private training institutions have been able to deliver quality training that is responsive to industry demands. Gram Tarang provides an example of a PPP model that assists young people who are constrained by low-income levels, inadequate skills, irregular employment and absence of opportunities for training and development. Practical implications – The model has some significant features which include its approaches to mobilization of prospective candidates, sharing of programme costs, accredited curriculum, design and delivery of training programmes in consultation with its partners, constant dialogue and interface with its partner organization, mobilization of resources and scaling up through a hub and spoke model. Originality/value – This paper tries to fill the gaps in the literature on inclusive skill building and employability.
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Fu, Min, Zhiyu Xu, Ning Wang, Xiaoyu Lyu, and Weisheng Xu. "“Peer-to-Peer Plus” Electricity Transaction within Community of Active Energy Agents Regarding Distribution Network Constraints." Energies 13, no. 9 (May 11, 2020): 2408. http://dx.doi.org/10.3390/en13092408.
Повний текст джерелаАнотація:
This paper proposes the concept “active energy agent (AEA)” to characterize the autonomous and interactive entities of power system. The future distribution network is a peer-to-peer (P2P) community based on numbers of AEAs. A two-stage “P2P Plus” mechanism is developed to address the electricity transaction within AEA community. In the first “P2P” stage, electricity is directly traded among AEAs via P2P price bidding. The model of P2P transaction is established, and the method of multi-dimensional willingness is adopted in price bidding. In the second “Plus” stage, the centralized coordination by distribution company (DisCo) is formulated as a constrained optimization problem, in which the objective is to maximize profit and the constraints are the basic rights of AEAs and line ratings of distribution network. A 30-bus test system including 29 AEAs and main grid is investigated. Numeric simulation results verify the effectiveness of the proposed models and methods regarding flow constraint. Comparative study reveals the economic motivations of AEAs to participate in P2P transaction, the efficiency of combined search, and the benefit of DisCo from pricing control.
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Huang, Wei, Pascale Defraigne, Giovanna Signorile, and Ilaria Sesia. "Improved Multi-GNSS PPP Software for Upgrading the DEMETRA Project Time Monitoring Service." Sensors 19, no. 20 (October 11, 2019): 4389. http://dx.doi.org/10.3390/s19204389.
Повний текст джерелаАнотація:
The H2020 DEMETRA project provides short latency clock monitoring services to the time users using the Atomium precise point positioning (PPP) software developed by the Royal Observatory of Belgium. In this paper, three recent updates of the current Atomium software are introduced: adding Galileo signals in the PPP computation; the option to constrain the receiver clock; PPP with integer ambiguity resolution. The advantages of these updates are demonstrated: Combining the Galileo and global positioning system (GPS) signals for PPP time transfer will further improve the frequency stability inside the computation batch; PPP with receiver clock constraint is not only used to reduce the short-term noise of the clock measurements but can also be used for some specific applications to a keep continuous clock solution in the computation batch or retrieve correct clock measurements from extremely noisy environments; the integer PPP allows a continuous clock solution, and improves the mid-term and long-term stability of the frequency transfer compared to the current PPP frequency transfer techniques.
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Osei-Kyei, Robert, and Albert P. C. Chan. "Implementation constraints in public-private partnership." Journal of Facilities Management 15, no. 1 (February 6, 2017): 90–106. http://dx.doi.org/10.1108/jfm-07-2016-0032.
Повний текст джерелаАнотація:
Purpose This paper aims to empirically investigate the differences and similarities on the implementation constraints in public–private partnership (PPP) in developing and developed economies/countries, represented by Ghana and Hong Kong, respectively. Design/methodology/approach A questionnaire survey was conducted with relevant experienced PPP practitioners in Ghana and Hong Kong. One hundred and three completed questionnaires were received for analysis. Kendall’s coefficient of concordance analysis, mean score ranking, Mann–Whitney U test and quartile grouping were used for data analysis. Findings The results show six implementation constraints with significant differences. Constraints related to the general investment climate of PPP projects (i.e. ecological conditions of PPP) are ranked higher in Ghana than in Hong Kong, whereas constraints related to the organisation and negotiations of PPP projects are higher in Hong Kong than in Ghana. Further, two constraints, lengthy delay in finalising negotiations and lengthy delay due to political debate, are very critical in both jurisdictions, whereas “negative public perceptions on PPP transactions” and “high use of unsolicited proposals” are of less challenge in the implementation of PPP in both jurisdictions. Originality/value The findings of this study contribute to knowledge on the international best practices of PPP. In addition, international private bidders would be informed of the mitigation measures to adopt when engaging in PPP arrangements in any part of the world, whether in a developing or developed economy country.
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Koul, Puneet, Piyush Verma, and Lalit Arora. "Road infrastructure development under PPP model in India: a credit rating perspective." Built Environment Project and Asset Management 11, no. 2 (February 5, 2021): 266–83. http://dx.doi.org/10.1108/bepam-08-2020-0137.
Повний текст джерелаАнотація:
PurposeThe study analyzes significant parameters defining the credit worthiness, economic viability and managerial efficiency of special purpose vehicles (SPVs) of infrastructure development firms engaged in the execution of road projects under PPP model in India.Design/methodology/approachThe study is based on a comprehensive review of credit rating reports of major rating agencies. In particular, 18 special purpose vehicles (13 BOT-toll–based and 5 BOT-annuity–based road projects) during the period 2010–2019 were considered to conduct a comparative analysis of their rating progression. Considering both financial as well as nonfinancial parameters, their segregation was done on the basis of strengths, constraints and key rating sensitivities influencing the ratings of SPVs involved in road projects under PPP model.FindingsPromoters' credibility emerged as an important factor affecting PPP credit ratings. Other prominent factors included nature of stretch and regulatory terms and conditions and the project's potential to generate cash flows. Inability of PPP projects to generate the projected levels of toll collections was a major constraint and hampered ratings over time. Growth in traffic was a key sensitive area in a toll-based project. Interestingly, despite the fixed nature of revenues, BOT (annuity) projects were impacted by rating changes.Research limitations/implicationsFewer sample projects (for which the data were available) was a constraint. Future research could consider larger data sets to provide deeper insights. An examination of credit rating parameters using rating reports of projects in other developing nations could provide meaningful implications. The findings of this research however cannot be undermined as the study bridges a gap in existing literature pertaining to the examination of PPP model from a credit rating perspective.Practical implicationsThis study would guide project developers, government agencies and awarding agencies of PPP road projects to anticipate the challenges and take adequate steps to mitigate them.Originality/valueResearch in the area of PPP projects is skewed toward risk assessment with respect to financial parameters. The present study emphasizes the rating framework of SPVs. Comprehensive examination of factors affecting project ratings in the form of projects' strengths, constraints and sensitivities would provide inputs to academics and researchers.
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Gong, Pan, Yue Teng, Xiao Li, and Lizi Luo. "Modeling Constraints for the On-Site Assembly Process of Prefabrication Housing Production: A Social Network Analysis." Sustainability 11, no. 5 (March 6, 2019): 1387. http://dx.doi.org/10.3390/su11051387.
Повний текст джерелаАнотація:
Although prefabrication housing production (PHP) has been widely advocated with advantages like ensured good quality and secured workplaces, its poor interoperability and fragmentation still causes various constraints, limiting the progress of projects. This paper aims to model the constraints and their relationships in task executions of different trades during the on-site assembly process of PHP. It was conducted through a typical PHP case study in Hong Kong to identify the critical trade associated constraints and their links during the on-site assembly process. Original data were collected by semi-structured interview, Delphi survey and questionnaire with representative professionals from the case. Social Network Analysis (SNA) was used to model the constraints and their interrelationships. The results indicated that seven trade-associated constraints were worth more attention. Three significant challenges were determined, indicating that the on-site team should focus on the availability of labor resources, optimal installation planning and effectiveness of communication mechanism. Smart work packaging (SWP)-enabled system for achieving automatic constraint identification and dynamic constraint relationship mapping under different constraint scenarios was suggested. This paper offers practical insights for scholars to conduct a trade-associated constraint identification study in the network manner and is expected to benefit practitioners on using the results for decision-making.
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Grubišić Šeba, Mihaela, Dubravka Jurlina Alibegović, and Sunčana Slijepčević. "Combating fiscal constraints for PPP development." Managerial Finance 40, no. 11 (November 7, 2014): 1112–30. http://dx.doi.org/10.1108/mf-07-2013-0176.
Повний текст джерелаАнотація:
Purpose – Public-private partnership (PPP) growth is often related to infrastructure development needs and public debt increase. Despite huge infrastructure (re)construction needs, the number of PPP projects in Croatia has been rather small so far. The purpose of this paper is to analyse the prospects for PPP projects development in Croatia in the near future. It is examined whether the stance of local authorities towards implementing PPP projects depends more on the necessity of developing infrastructure needs of local citizens or on the available funds for capital investments in local budgets, which are, after covering all operational expenditures, scarce. Design/methodology/approach – The Municipal Assemblies in European Local Governance (MAELG) survey data for Croatia are combined with available secondary data on local budgets’ revenues and expenditures in the period from 2008 to 2010 for the surveyed local government units. The differences between the answers of local representatives were tested for statistical significance by Pearson χ2 test, while ANOVA is used for testing statistical significance of budgetary data comparison. Some descriptive statistics’ results are also used. Apart from the quantitative data, qualitative research on PPPs, especially for fiscally constraint governments is used throughout the paper. Findings – The main findings of the paper are that most Croatian local units are severely fiscally constraint to implement any capital projects. Their public revenues are often reserved for covering operational expenditures only. Since local representatives are mostly affirmative towards private sector involvement in providing public services, there is a room for PPP projects in Croatia. Due to the fact that every PPP contract requires active participation of the public partner, two possible solutions are proposed: pooled financing with a possible option of project’ bonds issuance to institutional investors and engaging publicly owned assets into infrastructure projects’ development. Originality/value – The value of this paper is that it showed that there is little room for financing infrastructure development in Croatia if budgetary rules are followed straightforward. The paper aims to show fiscally constraint local governments a possible way for financing capital projects and rendering public services to their citizens. These solutions may also be applied in other indebted countries, especially if they own a significant portion of public assets.
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Aryani, Desy Yuli, and Mardwi Rahdriawan. "Kajian Peluang Kerjasama Pemerintah Swasta (Kps) Dalam Penyediaan Infrastruktur Di Pelabuhan Tanjung Emas Semarang." JURNAL PEMBANGUNAN WILAYAH & KOTA 11, no. 4 (August 3, 2016): 413. http://dx.doi.org/10.14710/pwk.v11i4.11551.
Повний текст джерелаАнотація:
ABSTRACT Port infrastructure in the transport system is a valuable asset for the national economy in order to face the globalization of free trade. Problems of provision of port infrastructure constraints in general is a factor financing. One of the government's efforts to overcome the problems in the provision of infrastructure financing is through the Public Private Partnership (PPP). This research was conducted in order to determine the opportunities and constraints of PPP implementation in the provision of port infrastructure by Master Plan Tanjung Emas Semarang. This study used a qualitative approach with a qualitative descriptive analysis techniques conducted on the characteristics of the PPP, the perception of government and stakeholders, as well as regulatory and institutional policies related to the implementation of the PPP. From this research it is known that in the construction and development of the port of Tanjung Emas does not currently use the PPP scheme because of the ownership status of Tanjung Emas port assets that are still in data collection, and a lack of understanding of the parties implementing the PPP. But the chances of implementing a PPP scheme is still possible in the area of ownership of assets remain below the government. Keyword: opportunities, constrains, PPP, infrastructure, port ABSTRAK Infrastruktur pelabuhan dalam sistem transportasi merupakan aset berharga bagi perekonomian nasional dalam rangka menghadapi globalisasi perdagangan bebas. Kendala permasalahan penyediaan infrastruktur pelabuhan pada umumnya adalah faktor pembiayaan. Salah satu upaya pemerintah untuk mengatasi permasalahan pembiayaan dalam penyediaan infrastruktur adalah melalui program Kerjasama Pemerintah Swasta (KPS). Penelitian ini dilakukan dengan tujuan untuk mengetahui peluang dan kendala pelaksanaan KPS dalam penyediaan infrastruktur pelabuhan berdasarkan Rencana Induk Pelabuhan Tanjung Emas Semarang. Penelitian ini menggunakan pendekatan kualitatif dengan teknik analisis deskriptif kualitatif yang dilakukan terhadap karakteristik KPS, persepsi pemerintah dan stakeholder, serta peraturan dan kebijakan kelembagaan terkait pelaksanaan KPS. Dari hasil penelitian tersebut diketahui bahwa dalam pembangunan dan pengembangan pelabuhan Tanjung Emas pada saat ini tidak menggunakan skema KPS dikarenakan status kepemilikan aset pelabuhan Tanjung Emas yang masih dalam pendataan, dan kurangnya pemahaman pihak-pihak pelaksana KPS. Namun peluang penerapan skema KPS masih mungkin dilakukan pada kawasan yang status kepemilikan asetnya masih berada dibawah pemerintah.
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Kaneva, Ophelia. "Public-private partnership in school education in Bulgaria: opportunities and constraints." Economic Thought journal 66, no. 6 (December 20, 2021): 30–40. http://dx.doi.org/10.56497/etj2166602.
Повний текст джерелаАнотація:
Public-private partnership (PPP) in school education in Bulgaria is an unknown but possible practice that can meet the main challenges in both education management and its implementation and impact. Arguments for its adequacy and value can be found in good international practices, in the experience gained, in the implementation of PPP in social services since 2004 and in the existence of relevant legislation. The article aims to develop and present the possibilities of using PPP in school education in Bulgaria. It analyzes good foreign practices, outlines the possibilities and limitations of PPP, and proposes a procedure for implementing PPP in school education. The conclusions of the study are that PPP will create a competitive environment in educational services, increase the quality of education and motivation to learn, and will introduce innovations and mechanisms to monitor and control.
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Ismail, Suhaiza, and Fatimah Azzahra Haris. "Constraints in implementing Public Private Partnership (PPP) in Malaysia." Built Environment Project and Asset Management 4, no. 3 (July 7, 2014): 238–50. http://dx.doi.org/10.1108/bepam-10-2013-0049.
Повний текст джерелаАнотація:
Purpose – The purpose of this paper is to study two objectives. First, it intends to scrutinize the challenges in implementing Public Private Partnership (PPP) by examining the factors that hinder the successful adoption of PPP in Malaysia. Second, it aims to investigate the differences in the perceptions of the government and the private sector pertaining to the hindrance factors. Design/methodology/approach – A questionnaire survey was used to elicit the perceptions of the public and private sectors concerning the constraints of PPP implementation in Malaysia. A total of 122 usable responses were obtained, which were analysed using Statistical Package for Social Sciences software. The mean score and mean score ranking were used to examine the importance of the hindrance factors based on the overall responses as well as on the respective responses of the public and the private sectors. An independent sample t-test was used to examine the differences in the perceptions between the two sectors. Findings – The overall results show that “lengthy delays in negotiation”, “lack of government guidelines and procedures on PPP”, “higher charge to direct users”, “lengthy delays because of political debate” and “confusion over government objectives and evaluation criteria” are the top five constraints for adopting PPP in Malaysia. In terms of the differences in the perceptions between the public and private sector groups, the statistical test results indicate that there are only significant differences in the perceptions for two hindrance factors. Originality/value – The paper contributes to the existing literature on PPP, which is currently limited, by focusing on the challenges of implementing PPP in a developing country (i.e. Malaysia). More importantly, this paper provides evidence concerning the differences in the opinion of two key players (i.e. the government and the private sector) on the PPP hindrance factors.