• Journal of the Earthquake Engineering Society of Korea
• /
• v.13 no.3
• /
• pp.11-19
• /
• 2009

Recently, concerns relating to the maintenance of large structures have been increased. In addition, the number of large structures that need to be evaluated for their structural safety due to natural disasters and structural deterioration has been rapidly increasing. It is common for the structural characteristics of an older large structure to differ from the characteristics in the initial design stage, and changes in dynamic characteristics may result from a reduction in stiffness due to cracks on the materials. The process of deterioration of such structures enables the detection of damaged locations, as well as a quantitative evaluation. One of the typical measuring instruments used for the monitoring of bridges and buildings is the dynamic measurement system. Conventional dynamic measurement systems require considerable cabling to facilitate a direct connection between sensor and DAQ logger. For this reason, a method of measuring structural responses from a remote distance without the mounted sensors is needed. In terms of non-contact methods that are applicable to dynamic response measurement, the methods using the doppler effect of a laser or a GPS are commonly used. However, such methods could not be generally applied to bridge structures because of their costs and inaccuracies. Alternatively, a method using a visual image can be economical as well as feasible for measuring vibration signals of inaccessible bridge structures and extracting their dynamic characteristics. Many studies have been conducted using camera visual signals instead of conventional mounted sensors. However, these studies have been focused on measuring displacement response by an image processing technique after recording a position of the target mounted on the structure, in which the number of measurement targets may be limited. Therefore, in this study, a model experiment was carried out to verify the measurement algorithm for measuring multi-point displacement responses by using a DIC (Digital Image Correlation) technique.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.18 no.3
• /
• pp.113-127
• /
• 2015

Recently, there has been a growing interest in UAS(Unmanned Aerial System), and it is required to develop techniques to effectively detect water body from the recorded images in order to implement flood monitoring using UAS. This study used a UAS with RGB and NIR+RG bands to achieve images, and applied supervised classification method to evaluate the accuracy of water body detection. Firstly, the result for accuracy in water body image classification by RGB images showed high Kappa coefficients of 0.791 and 0.783 for the artificial neural network and minimum distance method respectively, and the maximum likelihood method showed the lowest, 0.561. Moreover, in the evaluation of accuracy in water body image classification by NIR+RG images, the magalanobis and minimum distance method showed high values of 0.869 and 0.830 respectively, and in the artificial neural network method, it was very low as 0.779. Especially, RGB band revealed errors to classify trees or grasslands of Songsan amusement park as water body, but NIR+RG presented noticeable improvement in this matter. Therefore, it was concluded that images with NIR+RG band, compared those with RGB band, are more effective for detection of water body when the mahalanobis and minimum distance method were applied.

• Korean Journal of Veterinary Service
• /
• v.34 no.4
• /
• pp.409-416
• /
• 2011

This study was performed to evaluate the microbial contamination level of meat processing in butcher's shops in Seoul from January to November in 2010. A total of 695 samples (112 cotton work gloves, 342 utensils and equipments, 241 meat samples) were collected and the environmental hygiene of 89 butcher's shops was investigated. The aerobic plate count (APC), E. coli and pathogenic bacteria such as Staphylococcus aureus, Salmonella spp. were tested in the samples. As a result, the level of count on APC ranged $0{\sim}2.2{\times}10^6\;CFU/cm^2$ from the utensils & equipments, $1{\times}10^2{\sim}2.7{\times}10^8$ CFU/glove from the cotton work gloves and $1{\times}10^2{\sim}9.3{\times}10^6$ CFU/g from the meat samples. The level of count on E. coli ranged $0{\sim}2.5{\times}10^3\;CFU/cm^2$ from the utensils, $0{\sim}8.6{\times}10^4$ CFU/glove from the cotton work gloves and $0{\sim}1.4{\times}10^5$ CFU/g from the meat samples, respectively. Staphylococcus aureus and Salmonella spp. were detected in 11 samples and 2 samples from the cotton work gloves, utensils & equipments, respectively. The sanitation standard operating procedure (SSOP) was applicated at 49 butcher's shops. In order to improve sanitation of meat in butcher's shops, in this study, applications of SSOP, systemic sanitation education for employees, hygenic control of utensils & equipments, and continuous monitoring for microorganisms will be required.

• Journal of the Korean earth science society
• /
• v.38 no.2
• /
• pp.129-140
• /
• 2017

Global solar radiation was calculated in this research using ground-base measurement data, meteorological satellite data, and GWNU (Gangneung-Wonju National University) solar radiation model. We also analyzed the accuracy of the GWNU model by comparing the observed solar radiation according to the total cloud cover. Our research was based on the global solar radiation of the GWNU radiation site in 2012, observation data such as temperature and pressure, humidity, aerosol, total ozone amount data from the Ozone Monitoring Instrument (OMI) sensor, and Skyview data used for evaluation of cloud mask and total cloud cover. On a clear day when the total cloud cover was 0 tenth, the calculated global solar radiations using the GWNU model had a high correlation coefficient of 0.98 compared with the observed solar radiation, but root mean square error (RMSE) was relatively high, i.e., $36.62Wm^{-2}$. The Skyview equipment was unable to determine the meteorological condition such as thin clouds, mist, and haze. On a cloudy day, regression equations were used for the radiation model to correct the effect of clouds. The correlation coefficient was 0.92, but the RMSE was high, i.e., $99.50Wm^{-2}$. For more accurate analysis, additional analysis of various elements including shielding of the direct radiation component and cloud optical thickness is required. The results of this study can be useful in the area where the global solar radiation is not observed by calculating the global solar radiation per minute or time.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.48 no.5
• /
• pp.107-116
• /
• 2011

In this paper, a traffic adaptive sleep based medium access control (TAS-MAC) protocol for wireless sensor networks (WSNs) is proposed. The protocol aims for WSNs which consist of clustered sensor nodes and is based on TDMA-like schema. It is a typical schedule based mechanism which is adopted in previous protocols such as LEACH and Bit-Map Assisted MAC. The proposed MAC, however, considers unexpected long silent period in which sensor nodes have no data input and events do not happen in monitoring environment. With the simple traffic measurement, the TAS-MAC eliminates scheduling phases consuming energy in previous centralized approaches. A frame structure of the protocol includes three periods, investigation (I), transmission (T), and sleep-period (S). Through the I-period, TAS-MAC aggregates current traffic information from each end node and dynamically decide the length of sleep period to avoid energy waste in long silent period. In spite of the energy efficiency of this approach, the delay of data might increase. Thus, we propose an advanced version of TAS-MAC as well, each node in cluster sends one or more data packets to cluster head during the T-period of a frame. Through simulation, the performance in terms of energy consumption and transmission delay is evaluated. By comparing to BMA-MAC, the results indicate the proposed protocol is more energy efficient with tolerable expense in latency, especially in variable traffic situation.

• Journal of agricultural medicine and community health
• /
• v.31 no.2
• /
• pp.157-164
• /
• 2006

Objectives: Early diagnosis and treatment is the most important strategy to control malaria effectively. Microscopic examination of blood films is a traditional and standard method for diagnosing malaria, which takes a long time and needs expertise, Therefore, the alternative method, rapid diagnostic kit has been used for quick diagnosis in some counties, a highly infectious region by P. vivax. The purpose of this study was to evaluate the utility of malaria rapid diagnostic kit in Ganghwa county. Methods: The utility was evaluated by mean diagnosis time and sensitivity and specificity. For monitoring mean diagnosis time, 942 cases which were diagnosed for P. vivax were collected between 1998 and 2005, And for calculating sensitivity and specificity, 434 whole bloods in EDTA which were presented for P. vivax by microscopy and rapid diagnostic kit were collected between 2004 and 2005. Results: After malaria rapid diagnostic kit was used in 2003, mean diagnosis time has decreased to 3.36-3.14 day. The sensitivity and specificity of the rapid diagnostic kit was 98.2% and 98,5% and comparable to that of microscopic examination. Conclusions: The malaria rapid diagnostic kit is useful tool in a highly infectious region like Ganghwa county.

• Journal of the Korean Chemical Society
• /
• v.64 no.5
• /
• pp.277-290
• /
• 2020

In this study, four gifted students in the second year of middle school at Gifted Education Center of the National University in Jeollanam-do were surveyed students' perceptions of the effectiveness of science class using science writing heuristic in terms of metacognition and the goals of the 2015 revised science curriculum. Through questionnaires and interviews with gifted science students, science gifted students recognized that the science class using science writing heuristic had a positive effect on the four subdomains (planning, monitoring, control, and evaluation) of metacognition. For this reason, the science gifted students presented self-directed experience in designing experiments, continually checking the collected experimental data, feedback process, and reflecting experience in preparing conclusions. Science gifted students recognized that science class using science writing heuristic had a positive effect on the goals of the 2015 revised science curriculum(attitudes, inquiry, knowledge, Science·Technology·Society(STS), and the enjoyment and usefulness of science learning) that correspond to through inquiry science writing lessons. For this reason, the science gifted students presented self-directed inquiry experiences, continual inquiry experiences on the same subject, thinking process at each stage of inquiry, learning experiences through inquiry, experience of the whole inquiry process, and inquiry of phenomena closely related to real life. Therefore, for the effective science class, it is necessary to apply the characteristics of science class using science writing heuristic which is responded by science gifted students to general science class as well as science gifted class later.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.20 no.2
• /
• pp.157-164
• /
• 2014

This paper suggested the improvement of marine environmental impact assessment of different types of project by analyzing the consultation on the coastal area utilization(133cases) of the coastal development project for 4years(2010-2013). According to the analysis results, the erosion protection project needs to precede the accurate analysis of erosion reasons, predict exactly possible problems and establish the systematic system to verify the effect of erosion protection by monitoring after projects. The construction projects of revetments and coastal roads have to require to sublate, examine the reliability in structures, give consideration to the problems of coastal erosion by increase of reflected waves. In addition, flooding protection projects have got to require to select the waves for evaluation items in conjunction with the effects of abnormal waves. furthermore, waterfront construction projects need to establish comprehensive and methodical space plans and reinforce the review to conserve the natural environment and conduct nature-friendly development. There are many problems inherently related to coastal development Project. To these problems, however, it is required to support the project on the side of the legislation and conduct additional studies reflecting the characteristics by sea areas and projects.

• Journal of Environmental Policy
• /
• v.14 no.3
• /
• pp.75-94
• /
• 2015

The purpose of this study is to analyze the major issues discussed among Parties and provide a framework for predicting the agreements on those issues, prior to the final negotiation on a new legally-binding agreement on climate change adaptation in the United Nations Framework Convention on Climate Change (UNFCCC). The analyses of documents, adaptation actions, and work of the Ad Hoc Working Group on the Durban Platform for Enhanced Action (ADP) under the UNFCCC informed that the adaptation issue has primarily been focused on the support of developed country Parties for the adaptation of developing country Parties following the principle of the Convention, Common but Differentiated Responsibilities and Respective Capabilities (CBDR-RC). Three-year work of the ADP acknowledged the major issues on adaptation in the new climate agreement, which would be categorized as long-term and global aspects, commitments/contributions/actions, monitoring and evaluation, institutional arrangements, and loss and damage. A final agreement on each issue could be predicted by setting a zone of possible agreement in-between the two extremes of developing and developed country Parties and considering three major elements affecting the Parties' positions, national priority, adaptation action, and social expectation, which are proposed in this study. The three major elements should be considered in a balanced manner by Parties to draw a durable agreement that will enhance global adaptation actions from a long-term perspective. That is, the agreement needs to reflect adaptation actions occurring outside the Convention as well as social expectations for adaptation. It is expected that the new agreement on climate change adaptation, from a long-term and global perspective, would be an opportunity to reduce vulnerability and build resilience to climate change by incorporating global expectations.

• Journal of the Korean Society of Safety
• /
• v.11 no.2
• /
• pp.150-159
• /
• 1996

In this paper, an A-team(Asynchronous Team ) based approach for Reactive power and volage control considering static security assessment in a power system with infrastructural deficiencies is proposed. Reactive power and voltage control problem is the one of optimally establishing voltage level given several constraints such as reactive generation, voltage magnitude, line flow, and other switchable reactive power sources. It can be formulated as a mixed-integer linear programming(MILP) problem without deteriorating of solution accuracy to a certain extent. The security assessment is to estimate the relative robustness of the system in Its present state through the evaluation of data provided by security monitoring. Deterministic approach based on AC load flow calculations is adopted to assess the system security, especially voltage security. A security metric, as a standard of measurement for power system security, producting a set of discrete values rather than binary values, is employed. In order to analyze the above two problems, reactive power/voltage control problem and static security assessment problem, in an integrated fashion for real-time operations, a new organizational structure, called an A-team, is adopted. An A-team is an organization for agents which ale all autonomeus, work in parallel and communicate asynchronously, which is well-suited to the development of computer-based, multi-agent systems for operations. This A-team based approach, although it is still in the beginning stage, also has potential for handling other difficult power system problems.