Chihhsiong Shih

Non-uniform surface sampling techniques for three-dimensional object inspection

While the uniform sampling method is quite popular for point- wise measurement of manufactured parts, we present three novel sam- pling strategies that emphasize 3D non-uniform inspection capability. They are direct and indirect adaptive sampling and local adjustment sampling. The adaptive sampling strategy is based on a recursive sur- face subdivision process that applies two different approaches. One uses the direct triangular patch subdivision while the other uses the in- direct sectional adaptive approach. The direct adaptive sampling ap- proach can distribute points more closely around edges, corners, and vertices as found on the class of machined products. The indirect adap- tive sampling techniques extend optimum 2D sampling methods to 3D applications. The modified 2D adaptive sampling techniques are used sequentially twice; first, the critical cross sections are optimally selected, and then each section is optimally sampled to develop an accurate geo- metric description using a small number of sampling points. Beyond the practical application value of a technique to inspect curved surface ob- jects, this kind of technique is also of value in understanding the principle of optimum sampling in a 3D sense. The local adjustment sampling strat- egy uses a set of predefined starting points and then finds the local optimum position of each nodal point. This method approximates the object by moving the points toward object edges and corners. The pre- defined starting points sets include uniform and non-uniform sampling distribution generated by the direct adaptive sampling approach. The results show that the initial point sets, when preprocessed by the adap- tive sampling using triangular patches, are moved the shortest distance to edges and corners for global optimum approximation, again showing this methods superiority. The performance comparisons of applying uni- form sampling and adaptive sampling are made based on the MSE mean square error value between the real object surfaces and their approximating surfaces. The adaptive sampling methods exhibit better performance than the uniform sampling methods in reducing the MSE values with fewer sample points. In addition to the performance advan- tage over uniform sampling, the non-uniform sampling techniques we propose also proved to be integratable with view planning for the inspec- tion of products by different manufacturing processes.

A Model-Driven Multicore Software Development Environment for Embedded System

Multi-core programming is no more a luxury; it is now a necessity, because even embedded processors are becoming multi-core. However, the state-of-the-art techniques such as OpenMP and the Intel Threading Building Block (TBB) library are far from user-friendly due to the tedious work needed in explicitly designing multi-core programs and debugging. At the present days, a solution for above problems will be that to enhance the abstract level of multicore embedded software design. By leveraging on the expertise gained from Verifiable Embedded Real-Time Application Framework (VERTAF), we propose a Multi-Core version of VERTAF, called VERTAF/ Multi-core (VMC in short). VMC is an integrated development environment for multi-core embedded software architecture. Developers would be able to 1. describe their system requirements with SysML by using this environment, 2. model their design with SysML standard notation, 3. automatically apply a pattern structure into their design for a high quality multicore embedded system, 4. generate source code through a well-designed model; 5. map to different hardware architecture as assigned by the model, and 6. finally we can test the code.Using the model driven architecture (MDA) design flow in SysML, we saw a significantly improvement on productivity and quality of a multicore embedded programming over traditional approach.

Multi-objective exploitation of pipeline parallelism using clustering, replication and duplication in embedded multi-core systems

With the popularity of mobile device, people require more computing power to run emerging applications. However, the increase in power consumption is a major problem because power is quite limited in embedded systems. Our goal is to consider power consumption along with latency and throughput. We proposed a heuristic algorithm, called Parallel Pipeline Latency Optimization for high performance embedded systems (PaPiLO), based on clustering, replication and duplication, to minimize latency under power and throughput constraints. Experimental results show our method can get 15% latency reduction and 10% improvements for random task graphs and MPEG-2 decoder, respectively.

A Robust Watermark Scheme for Copyright Protection

In this paper, we propose a robust watermark technology that can be used to protect copyright. We enhance robustness of the watermark such that it can be used to protect the intellectual property even after serious attacks on the watermarked image. In the proposed watermarking, it embeds watermarks by Singular Value Decomposition and Distributed Discrete Wavelet Transformation techniques. Regarding our method, Singular Value Decomposition provides the robustness to protect the image from most attacks except cropping. Distributed Discrete Wavelet Transformation disperses watermarks within an image to resist cropping attacks. The robustness of our proposed watermark scheme has been verified experimentally against main watermark attack families such as geometric and signal processing attacks.

Billiard Combat Modeling and Simulation Based on Optimal Cue Placement Control and Strategic Planning

The selection of a best sequential shots for a given start cue position is a major challenging task in a billiard game. A new algorithm is proposed as a strategy to apply maximum tolerance angle search sequentially. The strategy considers combinations among all pockets and target object balls during both the pre and post collision shots selection processes. A simulation program is developed to test the strategy in a competition scenario by players with different proficiencies. The level of proficiency of players in the competition is controlled by a threshold value as a criterion to evaluate capability to conduct consecutive shots and when to give out right of play. The winning score of each game (win rate) is used as a performance comparison index among different gaming situations and to verify the effectiveness of the algorithm. The initial results of several simulation games using our strategy show that higher proficiency player can out beat lower proficiency player easily. This is consistent with the gaming situation in the real world, showing the consistency of our simulation program. The simulation also verifies that the play order does decide the final competition outcomes, when the players’ proficiencies are close to each other. This work is the first to investigate the effects of consecutive shots and order of play on the billiard gaming results. A low cost training system is proposed to verify the efficiency of the repositioning algorithm in real world settings. The system adapts an augmented reality technology to instruct users for reliable aiming assistance. It makes use of a vision system for cue ball, object ball locations and cue stick velocity tracking. In all, the simulation program can provide an initial proof of the effectiveness of the reposition algorithm in the competition situation. Experiments results of maximum tolerance angle all pocket search strategy using our training facility as tested by users with different skill levels all out performed the results without guidance for the set of users with the same proficiency.

An automatic smart shopping cart deployment framework based on pattern design

An automatic embedded software generation framework that can create and evolve Zigbee applications is proposed. The framework consists of two major modules, pattern extraction and code generation. Pattern extraction and development are designed to provide Zigbee application with model reuse and modification. SysML serves as a medium between pattern development and code generation. State diagrams, class diagrams and sequence diagram help describes a specific application scenario. A smart shopping cart application has been implemented using this pattern based software framework. The current location of a shopping cart has been monitored constantly by the WSN network through a signature sensing technique implemented by our lab. Both the electronic map on the server console and the PXA255 on board embedded system find a shortest path from the current location to the target product location assigned by user on the LCD screen. This evidence proves the success of the framework process. This software framework allows user to store the whole smart shopping application scenario in the design pattern repository. Further extension of this pattern can be exercised for creating other Zigbee applications such as patient localization in a hospital environment, item retrieval in large scale storage ware house, and green power energy saving applications etc.

The Architecture of Parallelized Cloud-Based Automatic Testing System

Software testing is the key of software quality control. However, software testing requires plenty of time, manpower and resources in hardware and software. Unfortunately, plenty of human errors may cause software testing become more difficult. To increase efficiency and reduce costs, automatic software testing is relatively important. It is possible to dynamically adjust the resources of hardware and software from the actual needs by introducing cloud technology. In this research, we proposed the paralleled cloud-based automatic testing system (PCATS) which have the advantages of real-time software testing and automatically computation scaling. PCATS can parallel the tests at the same time with distinct servers. The main contributions of this paper are automatically: (1) parse the source code to perform statistics analysis (2) generate test drivers and test cases (3) testing in virtual environments (4) paralleled testing (5) profile the consumed resources.

A Model Driven Software Framework for Zigbee Based Energy Saving Systems

While wireless sensor network drives the trend toward low-cost, in many industrial applications, it is not this factor that impacts on the rapid deployment of products on the markets but the rapidly changing application environment and design requirements. How to rapidly construct application software for different design requirements and operate smoothly are major challenges. An automatic embedded software generation framework that can create and evolve Zigbee applications is proposed. The framework consists of several major modules: pattern extraction, code generation and architecture mapping. Pattern extraction and development are designed to provide Zigbee application with the benefit of model reuse and modification. SysML serves as a medium between pattern development and code generation. State diagrams, class diagrams and sequence diagram help describes a specific application scenario. This research provides an embedded software development framework that integrates the heterogeneous readers and sensors interfaces with an optimal energy control model to enhance the quality of digital home living environments. The framework allows rapid deployment of the supporting software for a suite of energy control and sensing devices aiming not only at energy saving but allowing individual residents to monitor their energy use at any time. The closely similar pattern of power consumption profiles among hand written code and model derived code indicate that our tool has successfully completed the goal in synthesizing the required component codes and function successfully in controlling the comfort level with minimum amount of energy consumption. The stored energy efficient pattern can be reused at will for real world application of energy saving deployments.

Zero tolerance cue angle analysis and its effect on successive sink rate of a low cost billiard reposition control tutoring system

Selecting the best sequence of shots for a given cue position is not an easy task in a game of billiards. The repositioning of the cue after its collision with an object ball determines its success on successive shots. A previous paper by the author was able to assist users in order to perfect a shot based on a selection criterion of maximum angle tolerance. This paper further extends the aiming capability to include a calculation of the ideal speed for the repositioning of the cue ball. The system makes use of a vision system for cue and object balls, and cue stick tracking. Users are able to adjust the cue stick in terms of both the aiming direction and hitting velocity according to the guidance information analyzed by a gaming strategy of this work. A new strategy is proposed to apply the maximum tolerance angle search sequentially twice. One on the pre-collision shot and the second on the post collision path. Additional to the maximum tolerance angle criterion, this paper also proposes a new visible object ball count criterion to assist cue ball repositioning strategy for both direct and indirect shots. This criterion was developed based on an analysis of the zero tolerance zone angle. It has been specifically tested to verify its relation with the successive sink rate using proposed guidance system. The experimental results of the maximum tolerance angle repositioning strategy of our training facility as tested by users with different skill levels all out performed the results without the advice for the same set of users. In addition, the distribution pattern of maximum tolerance test showed the highest degree of similarity with that of accessibility count as user skill level increases. This not only proves the reliability of our training system, but also proves the effectiveness of our algorithm for optimal repositioning.

Supporting Design Enhancement by Pattern-Based Transformation

In general, a design pattern is usually documented in the form of an essay, with descriptions and rough design such as intent, motivation, structure, behavior, applicability and consequence, etc. Even though there are tools supporting pattern application, developers still may misuse patterns since misunderstanding. It may result failures of systems because of inconsistencies or design errors. In fact, the refinement process by applying a design pattern is merely the addition or removal of model elements in structure view. The refinement process for each design pattern is almost constant whenever the same pattern is applied. In this paper, we propose an approach for design pattern application and assisting the design enhancement by model transformation. Furthermore, we demonstrate our approach by a case study on a real-world multi-core embedded system PVE (Parallel Video Encoder), where a design pattern Command Pipeline is designed for the design enhancement.