• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.1
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• pp.64-77
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• 2012

In this study, the crack detecting system with digital image processing techniques based on the mathematical morphology method was developed to detect cracks in concrete structures. In the developed system, the image combining technique of reconstructing multiple images as an entire single image considering efficient management of analysis results was applied as an additional module. The developed system was verified through a field test with the cracked concrete culvert and the crack width of 0.2 mm was able to be detected in the 40m span. In the image analysis, the difference between calculated crack width and actual crack width were less than 0.08mm. For image combination in the stitching test of pattern images, the stitched image was identical with the original picture of entire subject in the visual perception level.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.4
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• pp.182-188
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• 2013

In this paper, we propose a complex-valued support vector machine (SVM) classifier which process the complex valued signal measured by pulse doppler radar (PDR) to identify moving targets from the background. SVM is widely applied in the field of pattern recognition, but features which used to classify are almost real valued data. Proposed complex-valued SVM can classify the moving target using real valued data, imaginary valued data, and cross-information data. To design complex-valued SVM, we consider slack variables of real and complex axis, and use the KKT (Karush-Kuhn-Tucker) conditions for complex data. Also we apply radial basis function (RBF) as a kernel function which use a distance of complex values. To evaluate the performance of the complex-valued SVM, complex valued data from PDR were classified using real-valued SVM and complex-valued SVM. The proposed complex-valued SVM classification was improved compared to real-valued SVM for dog and human, respectively 8%, 10%, have been improved.

• The Journal of the Acoustical Society of Korea
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• v.20 no.5
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• pp.83-91
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• 2001

This paper proposes the Focused beamforming to estimate the location of target residing near to the observation platform in the underwater environment. The Focused beamforming technique provides the location of target by the coherent summation of a series of incident spherical waveforms considering distinct propagation delay times at the sensor array. But due to the movement of the observation platform and the variation of the underwater environment, the shape of the sensor array is no longer to be linear but it becomes distorted as the platform moves. Thus the Focused beamforming should be peformed regarding to the geometric shape variation at each time. To estimate the target location, the artificial image plane comprised of cells is constructed, and the delays are calculated from each cell where the target could be proximity to sensors for the coherent summation. After the coherent combining, the beam pattern can be obtained through the Focused beamforming on the image plane. Futhermore to compensate the variation of the shape of the sensor array, the paper utilizes the Nth-order polynomial approximation to estimate the shape of the sensor array obeying the water pulley modeling. Simulation results show the performance of the Focused beamforming for different frequency bands of the radiated signal.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.11
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• pp.8-12
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• 2008

For the reduction of fabrication cost and process time of AC plasma display panel (PDP), indium tin oxide (ITO) layer was patterned as bus electrode using Nd:$YVO_4$ laser. In comparison with the chemically wet etched ITO patterns, laser ablated ITO patterns showed the formation of shoulders and ripple-like structures at the edge of the ITO lines. For the reduction of shoulders and ripple-like structures, pulse repetition rate and scan velocity of laser was changed. In addition, we analyzed a discharge characteristic of PDP test panel to observe how the shoulders and ripple-like structures influence on the PDP. Based on experimental results, the pattern etched at the 500 mm/s and 40 kHz was better than any other condition. From this experiment we could see the possibility of the laser direct patterning for the application to the patterning of ITO in AC-PDP.

• Journal of Korea Water Resources Association
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• v.55 no.1
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• pp.11-21
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• 2022

The COVID-19 started to spread at early 2020 in South Korea and has been threatening our life in many aspects. Countermeasures such as social distancing to prevent COVID-19 spread have brought many changes in our society an human life. In this study, as a part of the COVID-19 pandemic management, drinking water usage change is analyzed to evaluate potential risks on water supply service. We collected hourly water use data of residential area in S city, which is a mid-size city in South Korea, before and after the COVID-19 pandemic. The collected data were analyzed to reveal the changes in total water consumption, water usage weight, and hourly water-demand pattern caused by the COVID-19 pandemic. The case study revealed the noticeable changes in water consumption caused by the COVID-19 pandemic and required more secured and adaptive operation of drinking water system under the pandemic situation caused by infectious disease.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.310-315
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• 2017

Although studies evaluating the effects of the blasting vibration on the adjacent structures from various angles have continued, cases of securing the safety of the adjacent buildings and researching the proper blasting method for the field condition by analyzing the vibration waveform of the measuring field while performing the open pit blasting are poor. Therefore, it is necessary to present a remedy for blasting pattern selection through test blasting that is appropriate for field conditions, and is economical and efficient. In this study, open pit blasting work was conducted based on the separation distance applied according to the standard blasting method by test blasting and the vibration regulation standard in the road expansion construction site to measure the blasting vibration value, and the vibration prediction equation by blasting methods was examined using a regression analysis computer program to calculate K, N, and R of the confidence level 95%. By setting the blasting allowed vibration standard of the test blasting target area to 0.3cm/sec, and the charring weight and blasting method by the separation distances according to the blasting vibration estimation equation of the open pit blasting guideline and the blasting vibration estimation equation of the test blasting were compared/analyzed, it was possible to identify the factors that increased the working expenses. In addition, the measurement and analysis of the adjacent structures during open pit blasting and the blasting vibration were performed after selecting the most adjacent structure to the open pit blasting spot to analyze the problems on the test blasting procedure and analysis method in the open pit blasting design/construction guidelines, which appeared in the process of completing open pit blasting construction, and a remedy is presented.

• Journal of Life Science
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• v.13 no.1
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• pp.1-8
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• 2003

Antioxidant activity and biological properties in the MeOH extracts from different plant parts of Euonymus alatus (THNUB.) were measured by DPPH free radical scavenging ability and inhibition ability against xanthine/xanthine oxidase and proliferation in HL-60 cells. DPPH free radical scavenging activities in extracts of plant parts were high such as leaf, wing, root, seed and stem, respectively. The EtOAc fractions of plant parts were purified through LH-20 column chromatography and identified by GC/MS. LH-4 fraction and LH-5 fraction of leaf, stem and root showed stronger activities than other fractions in the inhibitor activity of DPPH and xanthine/ xanthine oxidase. $IC_{50}$ values of LH-4 fraction eluted from stem extracts showed such as 2.38 and 5.32 in DPPH and xanthine/ xanthine oxidase assay. Polyphenolic compounds were identified in purified LH-20 fractions showed highest $IC_{50}$ value in DPPH and xanthine/xanthine oxidase assay The activity of POD according to sampling time was high in root harvested in May and leaf harvested in September, respectively. The activity of SOD showed only in the extracts of stem in plant parts. SOD and POD in leaf were similar in the patterns of isozyme to those of stem. The purified extracts from Euonymus alatus (THNUB.) exerted inhibition ability of proliferation in HL-60 cells.

• Journal of Sericultural and Entomological Science
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• v.51 no.2
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• pp.147-152
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• 2013

The fibrinolytic activity of aqueous extracts from Korean indigenous insects were studied. Fibrinolytic activity of aqueous extract from 5 insects (larva and adult parts of Meloimorpha japonica, Allomyrina dichotoma, Cetonia pilifera, Apis mellifera) showed 2.7-fold potent than that of plasmin used as a positive control. In addition, the fibrinolytic activity was observed through the degradation products by SDS-PAGE. The extracts efficiently hydrolyzed ${\alpha}-$, ${\beta}-$ and ${\gamma}$ chains of human fibrinogen. This study suggested that aqueous extracts from Korean indigenous insects have potential in developing a useful source of antithrombosis agent(s).

• Proceedings of the Korea Information Processing Society Conference
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• 2012.11a
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• pp.1143-1145
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• 2012

본 연구에서는 인천 지역의 범죄의 특성 지역을 분석하기 위하여 기존의 이론적인 논의에 기초하며 AHP와 GIS와 연계를 통해 분석하고자 하였다. 이를 위해 인천의 범죄 우발지역을 볼 수 있는 공간적 패턴과 경찰서 내지 파출소의 적지를 선정하고 자료 분석 및 데이터 수집과 통틀어 공간 분석을 수행하며 이러한 분석을 통해 얻어진 여러 가지 요인들과 범죄 율을 나타내어 최종 자료를 구현하기 위한 연구를 한다. 범죄 율의 공간적 표현을 위해서 수식을 이용하여 범죄 율을 구했으며 인구 및 정확한 데이터들을 수집하여 분석하고 그대로 반영한다. AHP를 이용하여 설문조사 및 객관적인 판단과 가중치를 판단할 수 있는 중요한 척도가 되었으며, 이것들을 반영하여 최종 결과물에 현실성을 더하여, 실제로 예방조치를 취할 수 있도록 할 수 있을 것이다. 또한 GIS 소프트웨어에서 제공되는 좌표체계와 데이터베이스 및 SQL 등을 이용하여 현실성과 정밀성을 더하여 활용될 수 있음을 확인하였다.

• Journal of The Korean Society of Agricultural Engineers
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• v.56 no.1
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• pp.31-40
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• 2014

기후변화에 따른 기온상승과 강우패턴의 변화에 의한 농업의 취약성에 대한 연구는 주요 관심분야이다. 본 연구에서 기후변화가 한국의 2021~2040 (2030s), 2051~2070 (2060s) 및 2081~2100 (2090s)의 벼의 생산량과 관개요구량에 미치는 영향을 모의발생하여 분석 하였다. 세 가지 대표농도경로 (Representative Concentration Pathways: RCPs)에 대한 12개의 전지구 기후모형이 추정한 기후자료로부터 미래의 작물 물 요구량, 유효강우량, 관개요구량을 물수지 방법으로 계산하였다. Water Accounting Rice Model (WARM) 벼 작물모형을 보정하여 벼 생산량 추정에 이용하였다. 벼 생산량은 금세기 말에는 최대 40 %까지 감소하는 것으로 나타났다. 생산량은 특히 경남과 충남지방에서 크게 증가하는 것으로 나타났다. 생산량과 관개요구량의 시공간적인 불확실성을 분석한 바, 경북과 전남에서 2090s, RCP8.5때 불확실성이 가장 큰 것으로 나타났다. 미래에 일부 지역은 벼농사에 적합하지 않을 수도 있을 것으로 추정되었으며 기후변화 대응방안에 대한 연구가 필요할 것으로 판단된다.