Landslide Mitigation on the Sonoma Coast in Northern California

Heavy rains in late December 2001 and January 2002 caused approximately 100 meters of roadway to settle approximately 0.5 meters within a week along Highway 1 on the Sonoma County Coast (Post Mile 30.3). This area has a complex landslide history involving two active landslides. These landslides coalesce on a narrow section of Highway 1 approximately 130 meters above the Pacific Ocean. A tieback wall, sheet piles and a lightweight fill embankment had previously been constructed at this location to try to stabilize and maintain the roadway. The subsurface material at the site is composed of a matrix of very weak and extremely fractured shale and mudstone with the inclusion of sandstone blocks and fragments. The landslides are mainly driven by erosion at their base caused by storm related flows in Timber Gulch Creek and wave action undermining the slopes below the roadway. The Office of Geotechnical Design West was requested to provide Geotechnical expertise for mitigating the landslide in an expeditious manner. Several mitigation measures were considered to stabilize the landslide. The selected repair strategy was to move the roadway approximately 30 meters inland behind the failure plane of the landslide. This required the construction of a 21-meter high soil nail wall and the excavation of approximately 100,000 cubic meters of rock material. In addition, a new tieback wall needed to be constructed on the outside shoulder of the new realigned highway to prevent the current landslide scarp from encroaching into the new roadway. Design of the mitigation system was completed by March 2002 and construction started early April 2002 and completed by June 2003. This paper describes the geology and landslide history of the site and the observations, design details, soil nail pull out testing data, and wallmonitoring data obtained during the construction of the soil nail and the soldier beam tieback walls. This project demonstrated the efficiency and flexibility of soil nail and post tensioned tieback anchors for mitigating large landslides in extremely unfavorable geologic and topographic conditions. California Department of Transportation sponsored the project

CLASSIFICATION OF REMOTELY SENSED IMAGE DATA USING MULTITYPE INFORMATION

Classification of multispectral image data based on spectral information has been a common practice in the analysis of remote sensing data. However, the results produced by current classification algorithms necessarily contain residual inaccuracies and class ambiguity. By the use of other available sources of information, such as spatial, temporal, and ancillary information, it is possible to reduce this class ambiguity and in the process improve the accuracy. Therefore, the purpose of this research is to improve the accuracy of the classification by utilizing such multitype information. To accomplish this objective, three approaches are proposed. The first approach is a stochastic model in the time domain which utilizes spectral and temporal characteristics. The second approach involves the probabilistic and supervised relaxation methods which utilize multitype information. The third approach is a stochastic model in the spatial domain which attempts to extract interpixel class-conditional correlation and use this information with spectral characteristics to classify an object. As a result of adapting the above approaches to the problem, the following five new classifiers are developed. (1) Markov pixel classifier; (2) Non-iterative probabilistic relaxation; (3) Modified minimum distance object classifier; (4) Modified maximum likelihood object classifier; (5) Linear minimum distance object classifier. For all the above algorithms, software systems are developed or the existing software programs at the Laboratory for Applications of Remote Sensing (LARS), Purdue University are modified. All these methods are experimentally evaluated

Comparing Distortionary Effects of Iran Petroleum Contracts (IPC) and Production Sharing Contracts (PSC) Using Stochastic Dynamic Programming Model: The Case of South Azadegan field

This paper analyzes and compares the behavioral responses of the operator to the fiscal regime of the two types of contracts, Iran Petroleum Contract (IPC) and Production Sharing Contracts (PSC) with using the dynamic optimization approach (dynamic programming method). This paper aims to numerically compute the amount of distortions caused by the petroleum contracts, which creates some distortion in the investor's decision regarding to the neutral case that means there is no contractual restrictions including government share of resource rent, tax, extraction timing, cost recovery limit and so on. The focal point of this paper is the application of the stochastic dynamic programming for a real oil field in order to achieve the numerical results and using the deadweight loss (DWL) as an actual measure for assessment of the distortion of the contract regarding the first best case (neutral path). Accordingly, with using the information of the South Azadegan field, the results show that both fiscal terms of IPC and PSC have distortionary effects and the DWL of the IPC is more than that of PSC. For instance, in the reference scenario and reference oil prices the DWL of IPC and PSC are 22/22% and 21/14% respectively

Effect of Fast Curing Lights, Argon Laser, and Plasma Arc on Bond Strengths of Orthodontic Brackets: An In Vitro Study

Objective: Nowadays light-cured composites are used widely by orthodontists to bond brackets. As these composites require 20-40 seconds time per tooth to be light cured, more chair-time in needed compared to self-cured composites. In recent years, the argon laser and plasma arc lights have been introduced in dentistry to reduce this curing time. The purpose of this study was to compare bond strength of brackets bonded with the argon la-ser and plasma arc light with those bonded with the conventional halogen light.Materials and Methods: Fifty-one intact human premolars were randomly divided into three groups of 17 teeth each. Stainless steel twin premolar brackets (018- in Dyna lock, 3M Unitek) were bonded to the teeth using one of these curing devices in each group: the halogen unit (Coltolux 75, Switzerland), the argon laser unit (Bo-5, Iran ), and the plasma arc unit (Remecure 15, Belgium). The orthodontic adhesive was the same in the three groups (Transbond XT, 3M Unitek). After thermal cycling, the diametral tensilebond strength of specimens was measured using a debonding plier in a Zwick Universal Testing machine (Z/100, Germany).Results: The mean bond strengths was 17.344 MPa (SD=4.567) for halogen 19.172 MPa(SD=6.328) for laser and 19.322 MPa (SD=4.036) for plasma arc groups. No statistically significant difference existed in the mean bond strengths among three groups.Conclusion: Argon laser lights, significantly reducing the curing time of orthodonticbrackets without affecting bond strength, have the potential to be considered as advanta-geous alternatives to conventional halogen light