• International conference on construction engineering and project management
• /
• 2011.02a
• /
• pp.474-479
• /
• 2011

With Beijing's success in bidding for the 2008 Olympic Games, the increasing demand for infrastructure development and reduced public sector funding capacity has created a significant funding gap which calls for alternative project delivery methods such as Public-Private Partnership (PPP). Although the exploration of infrastructure projects using PPP model have been practiced since the late 80s, the $560 million National Stadium which served as the main venue for the Olympic Games is the first stadium project in China to be delivered under PPP operation. The project is generally considered successful despite the concession transfer in 2009 with concern of better serving the public interest. Compared to other infrastructure projects such as transportation, waste management and water management, the development of major sports facilities for mega-sports events with PPP has its own unique features and is subject to different major risks. This research identifies and analyzes critical risks in the implementation of PPP in major sports facility development through case study of the National Stadium project. A questionnaire survey and several interviews are conducted to solicit expert opinions from experienced practitioners. The purpose is to provide additional insights in risk management strategies and opportunities in China's PPP implementations in major sports facilities for policy makers and private sectors involved with investment decisions in future similar infrastructure development.

• Korean Journal of Construction Engineering and Management
• /
• v.19 no.2
• /
• pp.83-95
• /
• 2018

The aim of this paper is to develop a performance evaluation model for PPP (Public-Private Partnership) projects that appropriately reflects the important traits that are unique to PPP projects. To this end, 1) it defines a set of distinct perspectives involved in the PPP projects and their associated success factors that might differ amongst the perspectives; 2) it identifies the key performance indicators and suggests the performance evaluation criteria for each indicator; and 3) it builds a performance evaluation model by matching the success factors from each perspective with performance measure criteria as well as applies the model to the two selected BTO road projects in Korea. The process of model construction and its application confirms significant differences between the main stakeholder perspectives typically involved in PPP projects, which highlights the need for an evaluation model tailored for PPP projects by taking into account the distinct perspectives. The results from the PPP evaluation model developed in the study is compared against the results from the existing ex-post evaluation model for construction projects in general. The former shows a closer match with the results from the user satisfaction survey conducted. This new evaluation framework and the performance indicators entailed in it permits a balanced evaluation of PPP projects as it takes into account different perspectives involved in PPP projects as well as an understanding of the factors affecting the success of PPP projects. While the construction of the model is based on transport projects, it is applicable to different types of PPP projects through variation with the weight allocation amongst different success factors and/or additions or other adjustments to the performance evaluation criteria as required.

• Korean Journal of Biological Psychiatry
• /
• v.8 no.1
• /
• pp.79-84
• /
• 2001

Objectives : To investigate the effects of (-)-3-PPP(0.5, 2, and 10mg/kg, s.c.) and haloperidol(0.1, 0.5, and 2mg/kg, s.c.) on the extracellular dopamine concentrations, and the effect of pretreatment with (-)-3-PPP(2mg/kg) on the haloperidol(2mg/kg)-induced extracellular dopamine concentrations in the nucleus accumbens(NAS) of free moving rats. Methods : Dopamine levels in dialysate were determined with high pressure liquid chromatography(HPLC) with electrochemical detection(ECD). Results : (1)(-)-3-PPP had dual actions depending on the doses: at 2mg/kg, it decreased and at 10mg/kg, increased extracellular dopamine concentrations ; (2) haloperidol at all doses increased dopamine levels with higher dose having a greater increase; and (3) pretreatment of (-)-3-PPP reduced the increase in dopamine levels elicited by acute treatment with haloperidol. Conclusions : These findings suggest that pretreatment of (-)-3-PPP in low dose could accelerate the onset of therapeutic effect of haloperidol by diminishing the haloperidol-induced dopamine release in the limbic system.

• Proceedings of the Korea Contents Association Conference
• /
• 2005.05a
• /
• pp.507-513
• /
• 2005

This paper proposes a fast handoff scheme between PDSNs in 3GPPs network for a mobile node. It introduces a method by which handoff can be performed without reestablishing PPP connection that may occur in the process of performing handoff between PDSNs. The method for handoff between PDSNs which provide packet services to a mobile node, requires that the PDSNs should receive subscribers information about mobile nodes from their neighbor PDSNs forming a communication network. When the PDSN recognizes the mobile node moving into its coverage area, it can quickly establish a communication channel with the mobile node based on the already received subscriber information. As a result, handoff is performed without reestablishing PPP. Accordingly, handoff between PDSNs can be performed faster, removing time needed for establishing a PPP session with a terminal and for terminating a previously set up PPP session.

• Journal of Korean Society for Geospatial Information Science
• /
• v.22 no.1
• /
• pp.47-54
• /
• 2014

Precise Point Positioning (PPP) algorithms using GPS code pseudo-range measurements were developed and their accuracy was validated for the purpose of implementing them on a portable device. The group delay, relativistic effect, and satellite-antenna phase center offset models were applied as fundamental corrections for PPP. GPS satellite orbit and clock offsets were taken from the International GNSS Service official products which were interpolated using the best available algorithms. Tropospheric and ionospheric delays were obtained by applying mapping functions to the outputs from scientific GPS data processing software and Global Ionosphere Maps, respectively. When the developed algorithms were tested for four days of data, the horizontal and vertical positioning accuracies were 0.8-1.6 and 1.6-2.2 meters, respectively. This level of performance is comparable to that of Differential GPS, and further improvements and fine-tuning of this suite of PPP algorithms and its implementation at a portable device should be utilized in a variety of surveying and Location-Based Service applications.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.29 no.2
• /
• pp.109-117
• /
• 2018

In order to form focused inverse synthetic aperture radar(ISAR) images of a non-uniformly rotating target, rotational motion compensation(RMC) should be performed. Prominent point processing(PPP), one of the most representative RMC methods, is used to compensate nonlinear rotation motion by exploiting the phase signals of scatterers. In this paper, we propose a new RMC method based on the integrated cubic phase function(ICPF). The ICPF requires only one-dimensional(1-D) maximization to estimate the phases of multi-component signals. Simulation results using a point scatterers model in the absence of dominant scatterers validate that PPP based on ICPF can achieve well-focused ISAR images in real time.

• The Transactions of the Korea Information Processing Society
• /
• v.7 no.7
• /
• pp.2135-2148
• /
• 2000

Developing network software in embedded systems, such as digital set-top boxes, requires coding under limited computing resources. This paper presents the porting of Point-to-point Protocol (PPP) software, PPPD, to an embedded system. The PPP is the most popular link layer protocol for the information appliance, to an embedded system. In order to achieve this, problems to be solved for the porting were identified and methods to solve the problems were described. First, PPP source codes were divided into modules. Next, functions of each module were analyzed and interfaces between the modules were delineated. With the analysis results, porting to the embedded system was described. The normal operation of the ported software was verified with the help of a network packet analyzer. Finally, experiences during the porting were presented. The method developed in th paper can be applied to the porting of software to an embedded system as well as the porting of network software.

• Proceedings of the IEEK Conference
• /
• 2000.07b
• /
• pp.695-698
• /
• 2000

The services such as real-time audio and video applications have become increasingly popular, especially over the Internet. Furthermore, as being commercialized those contents on the Internet require quality of service (QoS) support to ensure their performance. PPP is the best solution to of for those kinds of services. The reason why we want to employ PPP is this satisfies most of the requirements associated with remote connectivity to an NSP, such as IP address assignment, security, and AAA (authentication, authorization and accounting). In addition, since ISPs and corporations are familiar with PPP based connectivity, easy migration from existing ISP infrastructure is expected, if QoS is guaranteed. But so for PPP has had no field to ensure the quality of service. This article presents the solution by using some tunneling protocols and the draft [1] that proposed additional LCP option fields to negotiate QoS. To communicate each other, after negotiating those option fields, over various protocols such as ATM, Ethernet, and etc. tunneling protocol is used. Following sections will mention those briefly. And the service provision to offer the end-to-end communication with negotiated QoS will also be proposed.

• KDI Journal of Economic Policy
• /
• v.42 no.4
• /
• pp.117-138
• /
• 2020

Few studies have specifically focused on the uncertainty of demand forecasting despite the fact that uncertainty is the one of greatest risks for governments and private partners in PPP projects. This study presents a methodology for finding robust contract conditions considering uncertainty in travel demand forecasting in a PPP project. Through a case study of an urban railway PPP project in Korea, this study uncovered the risk of excessive government payments to private partners due to the uncertainty in contracted forecast ridership levels. The results allow the suggestion that robust contract conditions could reduce the expected total level of government payments and lower user fees while maintaining profitability of the project. This study offers a framework that assists contract negotiators and gives them more information regarding financial risks and vulnerabilities and helps them to quantify the likelihood of these vulnerabilities coming into play during PPP projects.

• Journal of Positioning, Navigation, and Timing
• /
• v.12 no.2
• /
• pp.141-148
• /
• 2023

In this paper, impacts of tropospheric delay gradient correction on PPP positioning performance were analyzed. A correction for tropospheric delay error due to the gradient was created and applied using external data, and reference station data were collected on a sunny day and a rainy day to analyze the GPS only dual-frequency PPP positioning results. As a result, on the sunny day, the convergence time was about 35 minutes and the final 3D position error was 10 cm, regardless of whether the correction for the tropospheric delay error by the gradient was applied. On the other hand, on the rainy day, the 3D position error converges only when the correction was applied, and the convergence time was about 34 minutes. Furthermore, the final 3D position error was improved from 30 cm to 10 cm. In addition, the analysis of the PPP by reference station location on the rainy day showed that the PPP positioning performance was improved when the correction was applied to a user located in an area where the weather changes.