Joong-Ki Park

Design and implementation of 2 channels turbidity sensor modules

The turbidity has been classified as a basic item to measure water quality. This research team has developed a small turbidity sensor module to measure permanent turbidity based on moving objects that may freely swim on or under the water. This paper describes benchmark test results of the 2 channel turbidity sensor module with problems improved from the existing turbidity sensor module and the commercial products. The 2 channel turbidity sensor module not only has acquired the authorized test report issued by the Korea Testing Laboratory but also showed the performance within acceptable range of error at water quality under 8NTU comparing to the commercial products.

Java-based network management environment

This paper proposes a network management architecture composed of a manager browser and an intelligent agent using Java. The manager browser and the intelligent agent are Java application programs and the communication between them is carried out by Java classes. Adapting the Java environment with its byte-code and object oriented approach to network management offers a number of advantages. Noticeable points among them are portability on heterogeneous platforms, enhanced security, asynchronous operation of the manager and managed element due to multithreading, and improved adaptability to the popular Web browser format. Support for the existing MIB-II and the elimination of Basic Encoding Rules (BER) between the manager browser and the agent are the key features proposed in our approach.

Development of turbidity sensor modules and benchmark testing from biomimetic underwater robots

The turbidity has been classified as a basic item to measure water quality. This research team has developed a small turbidity sensor module to measure permanent turbidity based on moving objects that may freely swim on or under the water. This paper describes benchmark test results of the 2 channel turbidity sensor module with problems improved from the existing turbidity sensor module and the commercial products. The 2 channel turbidity sensor module not only has acquired the authorized test report issued by the Korea Testing Laboratory but also showed the performance within acceptable range of error at water quality under 8NTU comparing to the commercial products.

Design and Field Testing of Water Quality Sensor Modules Designed for Round-the-Clock Operations from Buoys and Biomimetic Underwater Robots

At the point of monitoring coverage, the legacy technologies of water quality measurement show the weakness. It manually or semi-automatically measures various water quality information at just only small parts of a large area. In this paper, we propose new water quality sensor apparatus which can consistently provide high resolution water quality data as well as attachable and PnP type deployable to underwater robots and buoys. The water quality sensor module, as a result of going through three water system tests in Han River, Gold River and Gapchun respectively and benchmarking with the commercial water quality meter, shows not only outstanding performance but also receives an official experimental certification by the supervisor of the Korea Testing Laboratory.

Design and Implementation of Sensor Modules Enabling Round-the-Clock Underwater Operations

The legacy technologies of water quality measurement show the weakness that it manually or semi-automatically measures various water quality information at just only small parts of a large area. In this paper, we propose new water quality sensor apparatus which can consistently provide high resolution water quality data as well as attachable and PnP type deployable to underwater vehicles. The water quality sensor module, as a result of going through two water system tests in Han River and Gabchun and benchmarking with the commercial water quality meter, shows not only outstanding performance but also receives an official experimental achievement by the supervisor of the Korea Testing Laboratory.

Resolution Adaptation of Digital Holograms Regardless of Wavelength and Reconstruction Distance

A practical algorithm is proposed for transforming a distortion-free holographic image out of the pixel size and wavelength mismatch between capture and holographic display devices. This method is demonstrated experimentally using numerical reconstruction, however can be complemented for all holographic display system, including 360-angle tabletop holographic configurations or wide-angle flat panel holographic display.

An optical reconstruction of hologram recorded by OSH using amplitude-only SLM and phase-only SLM

An optical reconstruction of a complex hologram by use of an amplitude-only spatial light modulator (SLM) and phase-only SLM is presented. The complex hologram of diffusively reflective object recorded by optical scanning holography (OSH) is converted to an off-axis hologram to eliminate twin image and background noise. With respect to holographic luminance contrast ratio, the optical reconstructed holographic image from amplitude-only SLM is superior to one from phase-only SLM as well as achieving the same result in numerical reconstruction.

Design and Implementation of Service-Oriented Task Model for Autonomous Service Robot

We identify and describe the challenges of robot task description and discuss the shortcomings of current approaches in meeting these challenges. We then identify a set of goals to guide the design of a task description language for the service-oriented autonomous robot. These goals led to the creation of event-based task description language, a XML-based language for describing user tasks as patterns of sub-tasks and events. ETDL is human-readable yet flexible enough to describe most types of service patterns to human especially in home environment. Finally, we experiment how well we met our goals and implications in the test bed equipped various information appliances using prototype robot, WeverR2

Robot manipulator control using recursive torque methods

A control law using recursive torque methods is designed for a 2-link SCARA robot manipulator. This control scheme uses previous torques acting on drive motors and error dynamics for present torques, and adopts relatively simple numerical methods and control algorithms that can be easily realizable. In order to evaluate the performance and robustness of the suggested control system, a 2-link SCARA robot manipulator is practically implemented by means of a dSPACE interface. It is found that the recursive torque controller shows a good tracking performance in spite of the presence of payload disturbances.