• The KIPS Transactions:PartD
• /
• v.8D no.6
• /
• pp.823-834
• /
• 2001

In the active databases, whenever an event occurs, active rules with the matching event specifications are triggered automatically, its action will be executed. Because these rules may in turn trigger other rules including themselves, the set of rules may be executing each other indefinitely. These problem can be solved by rule termination analysis, and it is efficient for the rule termination to execute in compile time of rule. In this paper we not only design rule compiler with rule termination analyzer, but also propose its execution model and algorithm. The completeness of proposed model is verified by algorithm formalization of rule termination analysis.

• The Journal of Engineering Geology
• /
• v.34 no.2
• /
• pp.173-191
• /
• 2024

Landslides pose significant threats to many countries globally, yet the development and implementation of effective landslide early warning systems (LEWS) remain challenging due to multifaceted complexities spanning scientific, technological, and political domains. Addressing these challenges demands a holistic approach. Technologically, integrating thresholds, such as rainfall thresholds, with real-time data within accessible, open-source software stands as a promising solution for LEWS. This article introduces LandScient_EWS, a PHP-based program tailored to address this need. The software facilitates the comparison of real-time measured data, such as rainfall, with predefined landslide thresholds, enabling precise calculations and graphical representation of real-time landslide advisory levels across diverse spatial scales, including regional, basin, and hillslope levels. To illustrate its efficacy, the program was applied to a case study in Medellin, Colombia, where a rainfall event on August 26, 2008, triggered a shallow landslide. Through pre-defined rainfall intensity and duration thresholds, the software simulated advisory levels during the recorded rainfall event, utilizing data from a rain gauge positioned within a small watershed and a single grid cell (representing a hillslope) within that watershed. By identifying critical conditions that may lead to landslides in real-time scenarios, LandScient_EWS offers a new paradigm for assessing and responding to landslide hazards, thereby improving the efficiency and effectiveness of LEWS. The findings underscore the software's potential to streamline the integration of rainfall thresholds into both existing and future landslide early warning systems.

• Journal of KIISE
• /
• v.44 no.1
• /
• pp.84-94
• /
• 2017

Recently, the importance of velocity, one of the characteristics of big data (5V: Volume, Variety, Velocity, Veracity, and Value), has been emphasized in the data processing, which has led to several studies on the real-time stream processing, a technology for quick and accurate processing and analyses of big data. In this paper, we propose a Squall framework using Time-triggered Message-triggered Object (TMO) technology, a model that is widely used for processing real-time big data. Moreover, we provide a description of Squall framework and its operations under a single node. TMO is an object model that supports the non-regular real-time processing method for certain conditions as well as regular periodic processing for certain amount of time. A Squall framework can support the real-time event stream of big data and micro-batch processing with outstanding performances, as compared to Apache storm and Spark Streaming. However, additional development for processing real-time stream under multiple nodes that is common under most frameworks is needed. In conclusion, the advantages of a TMO model can overcome the drawbacks of Apache storm or Spark Streaming in the processing of real-time big data. The TMO model has potential as a useful model in real-time big data processing.

• Journal of Broadcast Engineering
• /
• v.9 no.1
• /
• pp.74-82
• /
• 2004

In digital broadcasting, applications are computer programs executed by the set-top box(TV receiver) , and synchronized applications are those that perform tasks at the specified moments in the underlying video. This paper describes important concepts, standards, and skills needed to implement synchronized applications and explains how to integrate them to implement these applications. This Paper assumes the European data broadcasting standard, DVB-MHP. In DVB-MHP, scheduled stream events are recommended as a means of synchronizing applications with video streams. In this method, the application receives each stream event, and executes the action associated with the stream event at the time specified in the stream event. Commercially available stream generators, i.e., multiplexers, do not generate transport streams that support scheduled stream events. So we used a stream generator implemented in our lab. We implemented a synchronized application where the actions triggered by stream events are to display graphic images. We found that our synchronized application processes scheduled stream events successfully. In our experimentation, the stream events were synchronized with the video and the deviation from the intended time was within 240 ㎳, which is a tolerance for synchronization skew between graphic images and video.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.10 no.6
• /
• pp.1101-1105
• /
• 2006

Ubiquitous computing network comprises a variety of distributed service devices. Today Web services technology enables the heterogeneous devices to provide their own services and interact with each other via well-defined Internet protocol. Nevertheless, service devices in ubiquitous environments require more event-driven, autonomous interaction beyond rather passive service-oriented architecture of the present time. This paper presents an ECA (Event-Condition-Action) rule description language in an attempt to support capability for autonomous interactions among service-oriented devices in ubiquitous computing network. Specifically, the proposed WS-ECA is an XML-based ECA rule description language for web service-enabled devices. The rules are embedded in distributed devices which invoke appropriate services in the network if the rules are triggered by some internal or external events. The presented ECA-based device coordination approach is expected to facilitate seamless inter-operation among the web service-enabled devices in the emerging ubiquitous computing environment.

• The Journal of Korea Robotics Society
• /
• v.3 no.3
• /
• pp.226-236
• /
• 2008

In this paper, control software architecture is designed to enable a heterogeneous multiple humanoid robot demonstration executing tasks cooperating with each other. In the heterogeneous humanoid robot team, one large humanoid robot and two small humanoid robots are included. For the efficient and reliable information sharing between many software components for humanoid control, sensing and planning, CORBA based software framework is applied. The humanoid tasks are given in terms of finite state diagram based human-robot interface, which is interpreted into the XML based languages defining the details of the humanoid mission. A state transition is triggered based on the event which is described in terms of conditions on the sensor measurements such as robot locations and the external vision system. In the demonstration of the heterogeneous humanoid team, the task of multiple humanoid cleaning the table is given to the humanoid robots and successfully executed based on the given state diagram.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.7 no.6
• /
• pp.331-338
• /
• 2012

This paper presents a wireless sensor network protocol aimed for artificial structure monitoring. The proposed protocol enables the sensor network to operate at a low duty cycle for reducing power consumption with a high degree of synchronization accuracy. It also enables event-triggered measurement of environmental information with a high sampling rate and the transmission of the measured data with a low latency. The feasibility of the proposed protocol is demonstrated through experiments involving three sensor nodes and a sink node. Though a tunnel health monitoring was considered in the paper, the proposed protocol can be easily adopted in other areas.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2007.05a
• /
• pp.1291-1293
• /
• 2007

Due to dense deployment and innumerable amount of traffic flow in wireless sensor networks (WSNs), congestion becomes more common phenomenon from simple periodic traffic to unpredictable bursts of messages triggered by external events. Even for simple network topology and periodic traffic, congestion is a likely event due to dynamically time varying wireless channel condition and contention caused due to interference by concurrent transmissions. In this paper, we have proposed three mechanisms: upstream source count and buffer based rate control and snoop based MAC level ACK scheme to avoid congestion. The simulation results show that our proposed mechanism achieves around 80% delivery ratio even under bursty traffic condition

• Corrosion Science and Technology
• /
• v.8 no.6
• /
• pp.223-226
• /
• 2009

Polymer coatings are commonly applied to metal substrates to prevent corrosion in aggressive environments such as high humidity and under salt water. Once the polymer coating has been breached, for example due to cracking or scratches, it loses its effectiveness, and corrosion can rapidly propagate across the substrate. The self-healing system we will describe prevents corrosion by healing the damage through a healing reaction triggered by the actual damage event. This self-healing coating solution can be easily applied to most substrate materials, and our dual-capsule healing system provides a general approach to be compatible with most common polymer matrices. Specifically, we expect an excellent anti-corrosion property of the self-healing coatings in damaged parts coated on galvanized metal substrates.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.6 no.2 s.21
• /
• pp.61-68
• /
• 2006

The earthquake parameters are known to be responsible for determination of the initial free surface profiles of tsunamis. This study investigates the effects of earthquake parameters to variation of initial free surface profiles of tsunamis triggered by an impulsive undersea earthquake. The target event is the 1983 Central East Sea Tsunami recorded as the most devastating tsunami in Korea during last several decades. Among the earthquake parameters, the strike angle may play a most significant role in determining the initial free surface.