• Geophysics and Geophysical Exploration
• /
• v.8 no.2
• /
• pp.177-183
• /
• 2005

The subject of this paper is research into the application of electrical resistivity monitoring to detecting the water leakage of water utilization facilities. For this purpose, we installed a comprehensive monitoring system consisting of resistivity measurement, inclinometer, piezometer, and water gauge at an embankment. Using this monitoring system, we monitored the various kinds of measurement data and compared the resistivity structures and that of hydrological and engineering data in order to investigate the water leakage and stability of the embankment. The variant images of electrical resistivity at the embankment were provided from the monitoring data and we could accurately locate the portion of which resistivities have sharply changed. Furthermore, we could estimate the stability of the embankment more effectively and quantitatively by jointly interpreting the monitoring data of resistivity, water level, pore water pressure, and subsurface displacement. The monitoring experiments in this study led us to the conclusion that for the efficient maintenance of the water utilization facilities, monitoring the resistivity data and hydrological data would be much more preferable to performing the just one-time measurements.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.4 no.3
• /
• pp.27-42
• /
• 1984

The complexity and expensiveness of water resources projects have made optimum operation and design by computer-based techniques of increasing interest in recent years. Water resources problems in real world need many decisions under numerous constraints. In addition there are nonlinearities in the state and return function. This mathematical and technical troublesome must be overcome so that the optimum operation polices are determined. Then traditional dynamic optimization method encountered two major-cruxes: variable discretization and appearance of constraints. Even several recent methods which based on the Differential Dynamic Programming(DDP) have some difficulties in handling of constraints. This paper has presented New DDP which is applicable to multi-reservoir control. It is intended that the method suggested here is superior to abailable alternatives. This belief is supported by analysis and experiments(New DDT does not suffer course of dimensionality and requires no discretization and is able to handle easily all constraints nonlinearity).

• Journal of Korea Multimedia Society
• /
• v.8 no.5
• /
• pp.700-706
• /
• 2005

The immigration control system authorizes the immigration of travelers by means of passport inspections such as the judgment of forged passports, the search for a wanted criminal or a person disqualified for immigration, etc. The judgment of forged passports plays an important role in the immigration control system. Therefore, as the pre-phase for the judgment of forged passports, this paper proposed a novel method for the recognition of passport using ART2-based RBF network. The proposed method extracts the area of code and individual codes by applying the Sobel masking, the smearing and the contour tracking algorithm in turn to the passport image. This paper proposed the RBF network that applies the ART2 algorithm to the middle layer, and applied the enhanced RBF network to the recognition of individual codes. The results of the experiments for performance evaluation on the real passport images showed that the proposed method has the better performance compared with other approaches.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.48 no.10
• /
• pp.821-829
• /
• 2020

Health management system of airborne software repairs runtime errors to provide safety and to reduce cost of maintenance. It is critical to on-the-fly repair order violation errors, because it is difficult to identify them at the development phase. Previous work, called Repairing Atomicity Violations (Repairing-AV) diagnoses order violations for each access event by comparing execution order of accesses. As a result, Repairing-AV has time overhead that is proportional to the number of access events to shared variable. This paper presents a tool called On-the-fly Repairing System (ORS) that can repair order violations of object methods containing access events. The ORS diagnoses order violations by using correct order of object methods, and treats them by stalling its thread where the error is about to occur. Experimentation with five synthetic programs shows that ORS is more efficient than Repairing-AV when the number of access events is greater than sixty.

• The KIPS Transactions:PartD
• /
• v.10D no.1
• /
• pp.45-56
• /
• 2003

In the wireless environment, according to the development of technology, which is able to obtain location information of spatiotemporal moving object, the various application systems are developed such as vehicle tracking system, forest fire management system and digital battle field system. These application systems need the data model, which is able to represent and process the continuous change of moving object. However, if moving objects are expressed by a relational model, there is a problem which is not able to store all location information that changed per every time. Also, existing data models of moving object have a week point, which constrain the query time to the time that is managed in the database such as past or current and near future. Therefore, in this paper, we propose a data model, which is able to not only express the continuous movement of moving point and moving region but also process the operation at all query time by using shape-change process and location determination functions for past and future. In addition, we apply the proposed model to forest fire management system and evaluate the validity through the implementation result.

• Journal of the Korea Institute of Building Construction
• /
• v.9 no.6
• /
• pp.91-98
• /
• 2009

One role of waterproofing work is to block external moisture and water. Defects in waterproofing work in building construction brings on huge repair costs for related construction work as well as for the waterproofing layer itself. However, we don't have a quantitative probabilistic management method for waterproofing work to successfully anticipate and prevent defects. From an analysis of the literature and prior research, defects in the waterproofing work in the underground parts of buildings occur frequently. We selected Fluid-Applied Membrane waterproofing work as representing waterproofing work in the underground parts of a building, and researched the general types and causes of defects. In this study, we developed the Relative-FMEA (Failure Mode and Effect Analysis) approach that merges the Matrix method and FMEA. From a survey of experts, we deduced the most important management factors for Fluid-Applied Membrane waterproofing work for the underground parts of buildings.

• International Journal of Highway Engineering
• /
• v.14 no.3
• /
• pp.41-48
• /
• 2012

In this study the negative skin friction test of foundation pile was performed in order to monitor the negative skin frictional force acting on the steel pipe pile installed in soft soil. The monitored frictional stresses obtained from the long-term loading test. Through the long-term frictional stress monitoring test, the economical period for the construction of the superstructure was determined. The following conclusion were derived from this study: (1) In soft soil, negative skin friction increases with the increase in the rate of settlement. (2) In the friction relationship graph, the period where there is no frictional strain increase is verified and the time for the construction of the superstructure is determined. (3) The pile loading test was performed and the negative skin friction was compared with the test results. It was determined that the negative skin friction after driving was larger than the negative skin friction obtained from the loading test. 15 days after the construction, the monitored value was similar with the theoretical data. (4) It was determined that even during the occurrence of negative skin friction an economical construction management can be performed using the long-term monitoring method of negative skin friction.

• Journal of Environmental Impact Assessment
• /
• v.25 no.2
• /
• pp.155-164
• /
• 2016

Soil has been recognized as an important resource due to its finitude and valuable functions. Therefore, many countries have adopted soil quality related indicators in Strategic Environment Impact Assessment(SEIA). However, Korean SEIA has used limited indicators such as soil contamination until now. In this study, the SEIA on "Development Basic Plan" was modified for considering complex characteristics of soil and applied to "Bogeumjari Housing Supply Plan" and "Urban Management Plan". The performance of the SEIA considering soil characteristics was evaluated using a checklist for assessing consistency with upper plan, adequacy of alternatives, and feasibility of siting. Soil organic matter and soil erosion were derived as main indicators for "Basic Development Plans". The proposed SEIA technique equipped with soil indicators is proved to contribute to the soil resource conservation.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.8 no.3
• /
• pp.217-224
• /
• 2004

In 1980's, the concrete bridge decks were constructed with 4cm wearing surface layer instead of asphalt concrete overlays. After about 15 year service periods, deteriorations were appeared on the surfaces of highway bridge decks. Various field NDTs and lab tests were done to analysis the cause of the deterioration on the concrete deck surface. The main cause was the corrosion of rebars with thinner concrete top cover than the design value. The rebars with thinner concrete top cover was earlier corroded by penetrated chloride ions. If the appropriate top cover could be achieved, the bare concrete bridge decks can be used without earlier deteriorations.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.27 no.12C
• /
• pp.1251-1264
• /
• 2002

Currently, audio streaming services such as on-demand service and live service support only a limited number of clients. They also suffer from a lack of stability and degradation of service quality due to their inefficient use of network resources. Futhermore, since the streaming services usually do not consider dynamic services, they are very inconvenience to use. In order to resolve these drawbacks, we propose a novel audio streaming system based on MPEG-2 AAC file format which are facilitated with the network bandwidths efficiently. The proposed system supports QoS for audio streaming as well as guarantees a stability while streaming service is undergoing. Moreover, the system provides a dynamic interface which enables us to use the streaming service more easily and to manage streaming servers with convenient manner. On the contrary, most of the current available static interface streaming services are mainly depending only on a single fixed web page between client and server, which in consequence lead us to use unflexible static service environment. Our implementation results show the proposed system improves the performance compared to those of the currently existing systems that use MP3 file format. It also provides some benefits such as a stability of service and a easy to management of streaming servers.