Program Paths Research Articles

10.1109/ICCEA.2010.146

The Global Positioning System (GPS), Geographical Information System(GIS) and numerical processing technology et al. are involved in the paper. In the design of embedded mobile navigation system, the hierarchy of the system is plotted on the foundation of the demand for software principle and function. The main modules of the system are map data module, map matching and navigation module, path programming module. In the realization of digital map navigation, the operation system, which is the foundation of the software, is analyzed. Finally, the example using palmtop computer(iPAQ3970) and mobile telephone( Siemens 6688) is presented. The feasibility of the devise is affirmed.

From Practice to Theory: a social constructivist approach to teacher education

In contrast to a theory‐to‐practice teacher education program path is a social constructivist approach to teacher education, in which grounded theories are: (1) developed (individually and in small and large groups) based on information gathered from the world of practice, (2) compared and contrasted with already published theories and research, and (3) integrated with personal philosophies and values. Based on the grounded theories, ‘models’ of early childhood programs are then developed in groups. This article will present the effects of the social constructivist/grounded theory framework used in a beginning early childhood teacher education class. From inductive analyses of the data sources (on‐site observation and interview data, initial theories developed in small/large‐group discussion, critical reading information summaries, individual reflection papers, model program creations), six themes emerged: respectful interactions and environments, parent partnerships, diversity, connections between early childhood and elementary education, seeing issues from multiple perspectives, and early childhood education as a force for change. These themes were then connected to already published literature on constructivism and grounded theory, raising further questions for study about teacher education and teacher thinking.

Performance estimation of embedded software with instruction cache modeling

Embedded systems generally interact in some way with the outside world. This may involve measuring sensors and controlling actuators, communicating with other systems, or interacting with users. These functions impose real-time constraints on system design. Verification of these specifications requires computing an upper bound on the worst-case execution time (WCET) of a hardware/software system. Furthermore, it is critical to derive a tight upper bound on WCET in order to make efficient use of system resources. The problem of bounding WCET is particularly difficult on modern processors. These processors use cache-based memory systems that vary memory access time based on the dynamic memory access pattern of the program. This must be accurately modeled in order to tightly bound WCET. Several analysis methods have been proposed to bound WCET on processors with instruction caches. Existing approaches either search all possible program paths, an intractable problem, or they use highly pessimistic assumptions to limit the search space. In this paper we present a more effective method for modeling instruction cache activity and computing a tight bound on WCET. The method uses an integer linear programming formulation and does not require explicit enumeration of program paths. The method is implemented in the program cinderella and we present some experimental results of this implementation.

Whole program paths

Whole program paths (WPP) are a new approach to capturing and representing a program's dynamic---actually executed---control flow. Unlike other path profiling techniques, which record intraprocedural or acyclic paths, WPPs produce a single, compact description of a program's entire control flow, including loop iteration and interprocedural paths.This paper explains how to collect and represent WPPs. It also shows how to use WPPs to find hot subpaths , which are the heavily executed sequences of code that should be the focus of performance tuning and compiler optimization.

ワイヤ放電加工の加工精度に関する基礎的研究 （第３報） パワー制御と経路補正を組み合わせた大円弧凹コーナーＲの荒加工精度の改善方法

In this report, we propose a method to improve accuracy of concave large corner R by rough cut of a work piece where the corner R radius is greater than a half of cut groove width and the wire discharges symmetrically on whole front surface of the wire. In the control method, program path and discharge power are modified simultaneously at the corner R. The discharge power is adjusted so that difference between error of corner R on a middle surface and that on a top or a bottom surface of the work piece decreases within a allowable value. Program path is modified so that wire guides move along a path going a head of a desired corner R path, and the form of corner R on the top or the bottom surface of the work piece will be correct. The corner R radius is modified depending on the wire deflection.

Fundamental Study of Accuracy of Wire EDM (2nd Report)

This present paper investigates about accuracy of rough convex corner and convex corner R. Previous some reports proposed methods to improve corner and corner R accuracy of wire EDM. One method controls EDM conditions and other method modifies a program path at the corner and corner R, and 3rd method is a on-line system which detects wire deflection and corrects a contouring path. But 1st method has problems that the corner accuracy is insufficient and it lacks details to decide EDM parameters. Also 2nd method has a problem that the accuracy on top surface differs from that on middle cross section surface of a work piece. In addition 3rd method is only useful for special machines. In this paper we propose a combined power and path control method to improve the convex corner and corner R accuracy which is useful for ordinary operators. In the method, discharge power is adjusted so that the error of convex corner and corner R on the top or bottom surface of the work piece decreases within a desired value. The program path is corrected so as the residual error on the middle surface of the work piece to be 0.

An Integrated Path and Timing Analysis Method based on Cycle-Level Symbolic Execution

Previously published methods for estimation of the worst-case execution time on high-performance processors with complex pipelines and multi-level memory hierarchies result in overestimations owing to insufficient path and/or timing analysis. This does not only give rise to poor utilization of processing resources but also reduces the schedulability in real-time systems. This paper presents a method that integrates path and timing analysis to accurately predict the worst-case execution time for real-time programs on high-performance processors. The unique feature of the method is that it extends cycle-level architectural simulation techniques to enable symbolic execution with unknown input data values; it uses alternative instruction semantics to handle unknown operands. We show that the method can exclude many infeasible (or non-executable) program paths and can calculate path information, such as bounds on number of loop iterations, without the need for manual annotations of programs. Moreover, the method is shown to accurately analyze timing properties of complex features in high-performance processors using multiple-issue pipelines and instruction and data caches. The combined path and timing analysis capability is shown to derive exact estimates of the worst-case execution time for six out of seven programs in our benchmark suite.

An Acceptance Vector Semantics for Path Programs

In this paper, we consider two formal semantics for path programs. The first is a version of the net semantics introduced in [8] and further described in [7], and the second is an extension of the vector semantics of [15]. The extension involves the idea of tagging vectors with sets of sets of action names as with acceptance sets [3, 5] or refusal sets [1, 6] as used in the semantics of certain process algebras. The net semantics of [8, 7] associates a path program with an isomorphism class of labelled, marked nets - two such nets being isomorphic if they have identical pictorial representations and consequently describe the same system. A behaviour of such a class is an isomorphism class of cycle-free labeled nets showing the (partial) order in which conditions have held and events have occurred. We review these basic ideas and then present a version of the [7] semantics. We next present an acceptance vector semantics for path programs. An acceptance vector consists of a collection of sequences, one for each component path, describing the sequence of actions associated with the path in question during some period of activity, together with a set of actions which are available to continue the behaviour represented by the collection. Finally, we show that the two semantics are related in the sense that every net based behaviour may be transformed into an accceptance vector.

Development of an automated steering vehicle based on roadway magnets-a case study of mechatronic system design

Automated steering control is a crucial element of vehicle automation. The California PATH Program at the University of California at Berkeley has developed one such system using magnetic markers embedded under the roadway for lateral guidance. This system was demonstrated during the August 1997 National Automated Highway System Consortium Feasibility Demonstration, San Diego, CA, without a single failure. Developing a successful demonstration system not only required theoretical understanding of the various control problems involved, but also strong appreciation of all practical issues. In the paper, the comprehensive process of developing such automated steering control system is described. This process consists of control objectives' determination, system structure definition, vehicle dynamics validation, lateral sensing system development, steering actuator design, test track installation, control algorithm development, software/hardware integration, and vehicle testing. The entire process also serves as a good case study for mechatronic system design integrating mechanical components, electronic devices, intelligence, and feedback control to perform vehicle automation functions.

Designing and Validation of Error Detection Software

We propose a systematic approach for design and validation of error detection software. Formally, the semantic of a specification is represented by a transition system. This representation is then used to generate a flowgraph or ddgraph which is used to construct an execution path tree. The information obtained from this algorithm representation is used to aid in the design of software-based fault detection techniques for hardware faults. Flowgraph and ddgraph representations provide information to predict future program flow. During execution, the current program path is recorded, along with the expected path. Checks are placed to verify that the program path follows the predicted path. Algorithm-based fault tolerance (ABFT) techniques are used to detect data structure corrupting faults and to improve the fault coverage. Fault coverage provided by this approach for different types of hardware faults has been estimated through experiments with the software-based fault injection tool (SOFIT) and the data is presented to demonstrate the effectiveness of the method.

Trace-Based Abstract Interpretation of Operational Semantics

We present trace-based abstract interpretation, a unification of several lines of research on applying Cousot-Cousot-style abstract interpretation a.i. to operational semantics definitions (such as flowchart, big-step, and small-step semantics) that express a program‘s semantics as a concrete computation tree of trace paths. A program‘s trace-based a.i. is also a computation tree whose nodes contain abstractions of state and whose paths simulate the paths in the program‘s concrete computation tree. Using such computation trees, we provide a simple explanation of the central concept of collecting semantics, and we distinguish concrete from abstract collecting semantics and state-based from path-based collecting semantics. We also expose the relationship between collecting semantics extraction and results garnered from flow-analytic and model-checking-based analysis techniques. We adapt concepts from concurrency theory to formalize “safe” and “live” a.i.‘s for computation trees; in particular, coinduction techniques help extend fundamental results to infinite computation trees. Problems specific to the various operational semantics methodologies are discussed: Big-step semantics cannot express divergence, so we employ a mixture of induction and coinduction in response; small-step semantics generate sequences of program configurations unbounded in size, so we abstractly interpret source language syntax. Applications of trace-based a.i. to data-flow analysis, model checking, closure analysis, and concurrency theory are demonstrated.

Automatic Programming System for Shipyard Robots

The application of robots to variable tasks in unstructured environments presents a series of problems that must be solved in order to achieve viable results Common teaching-type robots cannot be applied in these cases as the programming time and labor investment far exceed the time and cost of direct manual production. Numerically controlled (NC) robots programmed off-line by modified NC methods have been applied with economic success to program robots directly from computer-aided design (CAD) data where tasks are sufficiently repetitive and the operating environment is sufficiently structured Similarly, off-line programming systems have been developed by various robot manufacturers to generate instructions from CAD data for their robots. Likewise, developers of 3D simulation software have devised methods to merge CAD data with physical models of robots and system hardware to produce robot path programs that approximate the tasks to be performed. Each of these systems is unable to provide a totally automated means to program robot tasks directly from CAD data due to inaccuracies in the real-world elements and/or the models, and due to a lack of knowledge about the processes. A new approach to automatic robot programming is needed that is capable of dealing with:inherent differences between the CAD models and the real-world parts;uncertainties regarding the precise location and accessibility of the parts relative to the robot:process knowledge required to adapt these differences and uncertainties; andprocess knowledge essential to optimizing robot activities. Such an automatic robot programming system is being developed to meet the dual-use defense and commercial ship construction needs of American shipyards under the Technology Reinvestment Project (TRP) for Shipbuilding Robotics. This system automates the programmer's task of identifying location of welds, assigning weld process parameters and adaptive welding strategies to each joint. A procedural diagram for this system is shown in Figure 1. The results and benefits of this approach are described herein. Fig. 1Procedure for automatic off-line robot task planning

Flexible Robotics for Shipbuilding

A twelve-member team is developing a new paradigm in shipbuilding robotics. The consortium, led by CYBO Robots in conjunction with the Technology Reinvestment Project (TRP), includes shipyards, hightech companies, technical institutes, universities, and federal agencies. The objective is to create and implement robotic technology that allows shipyards to move confidently into automated production of both commercial and combatant vessels, while making maximum use of existing facilities and personnel. Keys to the effort are reliable, easy-to-run robots driven by open-architecture controllers which develop robot path programs directly from the CAD model of the ship. Examples of applications for these robots are shown in Fig. 1. Differing from previous approaches, this project attacks the problems which traditionally have kept robots out of U.S. shipyards, and provides flexible solutions to organizations with limited financial resources and automation experience. This paper describes how the program is developing new approaches to the issues of component fit-up, part dimensional tolerances, and robot programming, as well as portability, usability, and acquisition costs. Also presented is the strategy for interconnecting these advanced technologies using a readily available PC-based environment that conforms to emerging open architecture standards. Fig. 1 Flexible robotics for shipbuilding

Performance analysis of embedded software using implicit path enumeration

Embedded computer systems are characterized by the presence of a processor running application-specific dedicated software. A large number of these systems must satisfy real-time constraints. This paper examines the problem of determining the extreme (best and worst) case bounds on the running time of a given program on a given processor. This has several applications in the design of embedded systems with real-time constraints. An important aspect of this problem is determining which paths in the program are exercised in the extreme cases. The state-of-the-art solution here relies on an explicit enumeration of program paths. This solution runs out of steam rather quickly since the number of feasible program paths is typically exponential in the size of the program. We present a solution for this problem that does not require an explicit enumeration of program paths, i.e., the paths are considered implicitly. This solution is implemented in the program cinderella (in recognition of her hard real-time constraint-she had to be back home at the stroke of midnight), which currently targets a popular embedded processor-the Intel i960. The preliminary results of using this tool are also presented here.

A method of progressive constraints for manipulation planning

We present a method for manipulation planning derived from a systematic approach to constrained motion planning. We call it a method of progressive constraints. It replaces an original problem by a series of progressively constrained ones, and makes a solution of the current problem converge toward a solution of the original problem. The manipulation constraints are analyzed and it is shown how they can be introduced progressively. The progressive constraints framework can thus be used for solving manipulation planning problems. The general algorithm proposed for constrained motion planning can be derived from a standard geometric path planner. We use the variational dynamic programming path planner, in which at every iteration a current path is used to generate a submanifold that is searched for a better path.

AHS safe control laws for platoon leaders

The automated highway system (AHS) architecture of the California PATH program organizes traffic into platoons of closely spaced vehicles. A large relative motion between platoons can increase the risk of high relative velocity collisions. This is particularly true whenever platoons are formed or broken up by the join and split control maneuvers and by the decelerate to change lane control maneuver, which allows a platoon to create a gap before switching from one lane to another. In this paper we derive a safety region for the relative velocity between two platoons. By guaranteeing that the relative velocity between platoons remains in this region, impacts of high relative velocity can be avoided. Under normal operating conditions, there are four control laws for a platoon leader: leader law, join law, split law, and decelerate to change lane law. For each control law, a desired velocity profile for the platoon that satisfies safety and time-optimality requirements is derived. A nonlinear velocity controller is designed to track the desired velocity profile within a given error bound. When safety is not compromised, this controller keeps the acceleration and jerk of the vehicles in the platoon within comfort limits.

Safety Oriented Maneuvers for IVHS

SUMMARY The IVHS architecture of the California PATH program organizes traffic into platoons of closely spaced vehicles. Platoons are formed and broken up by two longitudinal control maneuvers, the merge and the split. A third longitudinal maneuver, decelerate to change lane, allows a platoon switching from one lane to another to enter its new lane at a safe spacing and speed. The maneuvers, particularly the merge, can be potentially hazardous. In a merge, the cars in the trail platoon are moving faster than those in the lead platoon, while the gap separating the two platoons is smaller than usual. A sudden deceleration by the lead platoon could cause a high-speed collision. If the relative velocities of the merging platoons can be constrained so that they are guaranteed never to collide at a high relative velocity, the merge can be considered safe. A maximum safe velocity for the trail platoon can be found for any given spacing and lead-platoon velocity. This paper presents a merge maneuver in which the ...

Coronary disease risk factor reduction and behavior modification in minority adolescents: The PATH program

To evaluate the impact of a unique school-based program of exercise, health education, and behavior modification on health knowledge, health behaviors, coronary risk factors, and cardiovascular fitness in minority adolescents. A total of 346 students from an inner-city public high school participated in health promotion intervention or regular physical education volleyball classes. Subjects were African-American (47%), Asian-American (9%), Hispanic (21%), white (3%), and other (19%). The health promotion curriculum consisted of 11 weeks of daily circuit training exercise and health lecture-discussions. The groups were similar in age, height, weight, ethnicity, and socioeconomic status. Following intervention both boys (P < .001) and girls (P < .006) significantly improved health knowledge test scores. Significant benefits for girls included improved dietary habits (P < .05), reduced cholesterol (P < .004), and higher estimated V(O2)max (P < .0001). There were no other significant changes in boys. The results suggest that a school-based health promotion program of exercise and health lecture-discussion is beneficial for multiethnic, inner-city adolescents, especially females.

The freeway service patrol evaluation project: Database support programs, and accessibility

This paper discusses the Freeway Service Patrol (FSP) Evaluation Project conducted under the California PATH program. The goal of this project was to determine the cost effectiveness of the FSP program along a 10-mile “beat” on I-880, near Hayward, California. We collected data from three different sources: loop detector data, probe vehicle data and incident log data. We describe these sources in detail and the problems that were encountered with them. We also discuss the support programs developed to process this data, and the efforts to place the data and the programs on-line for use by researchers around the country.

Performance analysis of embedded software using implicit path enumeration

Embedded computer systems are characterized by the presence of a processor running application specific dedicated software. A large number of these systems must satisfy real-time constraints. This paper examines the problem of determining the extreme (best and worst) case bounds on the running time of a given program on a given processor. This has several applications in the design of embedded systems with real-time constraints. An important aspect of this problem is determining which paths in the program are exercised in the extreme cases. The state of the art solution here relies on an explicit enumeration of program paths. This runs out of steam rather quickly since the number of feasible program paths is typically exponential in the size of the program. We present a solution for this problem that does not require an explicit enumeration of program paths, i.e., the paths are considered implicitly . This solution is implemented in the program cinderella 1 which currently targets a popular embedded processor --- the Intel i960. The preliminary results of using this tool are also presented here.