• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.6A
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• pp.861-872
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• 2008

Concrete-filled glass fiber reinforced polymer tubes are often used for marine structures with the benefit of good durability and high resistance against corrosion under severe chemical environment. Current research presents results of a comprehensive experimental investigation on the behavior of axially loaded circular concrete-filled glass fiber reinforced polymer tubes. This paper is intended to examine several aspects related to the usage of glass fiber fabrics and filament wound layers used for outer shell of piles subjected to axial compression. The objectives of the study are as follows: (1) to evaluate the effectiveness of filament winding angle of glass fiber layers (2) to evaluate the effect of number of GFRP layers on the ultimate load and ductility of confined concrete (3) to evaluate the effect of loading condition of specimens on the effectiveness of confinement and failure characteristics as well, and (4) to propose a analytical model which describes the stress-strain behavior of the confined concrete. Three different types of glass fiber layers were chosen; fabric layer, ${\pm}45^{\circ}$ filament winding layer, and ${\pm}85^{\circ}$ filament winding layer. They were put together or used independently in the fabrication of tubes. Specimens that have various L:D ratios and different diameters have also been tested. Totally 27 GFRP tube specimens to investigate the tension capacity, and 66 concrete-filled GFRP tube specimens for compression test were prepared and tested. The behavior of the specimens in the axial and transverse directions, failure types were investigated. Analytical model and parameters were suggested to describe the stress-strain behavior of concrete under confinement.

• Convergence Security Journal
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• v.22 no.5
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• pp.21-35
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• 2022

The use of digital information according to the development of information and communication technology and the 4th industrial revolution is continuously increasing and diversifying, and in proportion to this, crimes using digital information are also increasing. However, there are few cases of establishing an environment for processing and analysis of digital evidence in Korea. The budget allocated for each organization is different and the digital forensics laboratory built without solving the chronic problem of securing space has a problem in that there is no standard that can be referenced from the initial configuration stage. Based on this awareness of the problem, this thesis conducted an exploratory study focusing on tools and equipment necessary for building a digital forensics laboratory. As a research method, focus group interviews were conducted with 15 experts with extensive practical experience in the digital forensic laboratory or digital forensics field and experts' opinions were collected on the following 9 areas: network configuration, analyst computer, personal tools·equipment, imaging devices, dedicated software, open source software, common tools/equipment, accessories, and other considerations. As a result, a list of tools and equipment for digital forensic laboratories was derived.

• The Journal of Bigdata
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• v.8 no.1
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• pp.157-165
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• 2023

Seafood is a major source of protein in many countries and its consumption is increasing. In Korea, consumption of seafood is increasing, but self-sufficiency rate is decreasing, and the importance of safety management is increasing as the amount of imported seafood increases. There are hundreds of species of aquatic products imported into Korea from over 110 countries, and there is a limit to relying only on the experience of inspectors for safety management of imported aquatic products. Based on the data, a model that can predict the customs inspection results of imported aquatic products is developed, and a machine learning classification model that determines the non-conformity of aquatic products when an import declaration is submitted is created. As a result of customs inspection of imported marine products, the nonconformity rate is less than 1%, which is very low imbalanced data. Therefore, a sampling method that can complement these characteristics was comparatively studied, and a preprocessing method that can interpret the classification result was applied. Among various machine learning-based classification models, Random Forest and XGBoost showed good performance. The model that predicts both compliance and non-conformance well as a result of the clearance inspection is the basic random forest model to which ADASYN and one-hot encoding are applied, and has an accuracy of 99.88%, precision of 99.87%, recall of 99.89%, and AUC of 99.88%. XGBoost is the most stable model with all indicators exceeding 90% regardless of oversampling and encoding type.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.6D
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• pp.1003-1010
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• 2006

This study developed a traffic accident information management system based on WebGIS that can process a lot of data for giving effectively diagnosis of traffic accidents in serious damage circumstances by traffic accident. Also, this study presents a way to compose and to convey traffic accident information. In addition, non-spatial attributes as well as spatial attributes about traffic accidents information be integrated and managed by the system. To provide Web service, we developed modules that can supply visually spatial information and traffic accidents data through ASP, Javascript, ArcIMS based on Web and constructed a server. And constructed system include a function that offer the now situation of traffic accident in real time, which supply the statistical data of traffic accident through Web as soon as user entry data in comparison with previous way that preparatory period until traffic accidents data is supplied to peoples had been long. Traffic accidents are analyzed with only nonspatial attribute by simply collecting in the past. However, system constructed by this study offer new function that can grasp visually accident spot circumstance and use detailed content and accurate location data as well as statistical data of traffic accidents. Also, it offer interface that can connect directly with accident charge policeman.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.6B
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• pp.641-649
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• 2006

The behavior of a three-dimensional pure rectangular water jet with aspect ratio of 10 was experimentally investigated based on the results of the mean velocity field obtained by PIV. The saddle back distribution was observed in the lateral distribution along the major axis. The theoretical centerline velocity equation derived from the point source concept using the spreading rate for the axisymmetric jet was in good agreement with the measured centerline velocity and gave the division of the potential core region, two-dimensional region, and axisymmetric region. The range of the two-dimensional region divided by the criterion of the theoretical centerline velocity decay for the aspect ratio of 10 was observed to be smaller than that of the transition region. The applicability of the two-dimensional model to the behavior of the rectangular jet with low aspect ratio or the wastewater discharged from a multiport diffuser in the deep water of real ocean may result in significant error in the transition and axisymmetric regions after the two-dimensional region. In the two-dimensional region, the Gaussian constant tended to be conserved, and the spreading rate slightly decreased at the end of the two-dimensional region. The normalized turbulent intensity along the centerline of the jet initially abruptly increased and showed relatively higher intensity for higher Reynolds number.

• 한국노년학
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• v.29 no.1
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• pp.259-273
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• 2009

Purpose: This research was conducted to determine the effects of a multifactorial fall prevention program applying HSEP(Home Support Exercise Program) on physical balance and gait, leg strength, fear of falling and falls efficacy of the community-dwelling elderly. Method: The design of this study was a nonequivalent control group pretest-posttest design. There were 20 subjects in the experimental group and 21 in the control group. The fall prevention program consists of HSEP and fall related education. The intervention was performed for once a week in the senior citizen center and twice a week at home for 8 weeks. Results: There were significant differences in physical balance and gait, leg strength(hip extensor, hip flexor, knee flexor, ankle plantarflexor, ankle dorsiflexor) and falls efficacy between the experimental group and control group. Conclusion : The fall prevention program applying HSEP used in this study was very effective in increasing physical balance and gait, leg strength and falls efficacy. Finally this study would recommended that a fall prevention program applying HSEP should be extended to community facilities such as elderly welfare center and nursing home.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2021.04a
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• pp.25-25
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• 2021

전 세계에 유통되고 있는 Cypripedium속 식물 56종 중 한반도에는 4종이 분포하고 있다. 국내의 Cypripedium속 식물 중 멸종위기 1급 식물은 광릉요강꽃과 털복주머니란이 있으며, 복주머니란은 멸종 위기 2급 식물로 분류하였다. 본 연구는 이러한 복주머니란 식물의 육묘기술을 개발하기 위하여 연구를 수행하였다. 처리는 원예용 상토, 마사토 100%, 질석 2 : 펄라이트 1의 비율로 혼합한 인공토양, 산야초 상토, 소립인 난석 등 5처리를 하여 복주머니를 스티로폼 박스(가로 40, 세로 50, 높이 15cm)에 식재하여 4개월 경과 후 조사한 결과 산야초 상토에서 출아율이 67.0%로 가장 많았으며, 질석 2 + 펄라이트 1의 처리구가 53.0%, 소립인 난석 처리구가 48.0%순으로 높았다. 출아율이 가장 좋았던 산야초 상토의 경우 초장은 3.0cm, 엽수는 주당 1.9개, 엽폭은 1.0cm로 다른 처리구보다 생육이 양호하였다. 또한 털복주머니란 실생묘를 노지에서 1년 동안 순화한 묘를 자생지 외 지역의 적응성을 확인하기 위해 경기도 양평에 위치한 국립수목원 내 Cypripedium 전문 전시원에 660주를 봄에 식재하였다. 그해 9월에 생존율 을 조사한 결과 52.5% 이었고, 초장이 5.8cm, 뿌리수는 주 당 3.6개, 뿌리길이는 6.4cm 등 생육도 정상적으로 진행되는 것으로 조사되었다. 이와같은 연구를 바탕으로 멸종위기종인 복주머니란의 적정 환경 조성과 육묘기술 및 현지 적응성을 향상시킨다면 멀지 않은 시기에 복주머니란의 복원 사업은 성공적으로 마무리될 것으로 판단된다..

• Journal of Life Science
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• v.33 no.12
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• pp.1046-1051
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• 2023

Cigarette smoking is one of the major causes of preventable diseases, disability, and death in Korea and worldwide. It has been clearly linked to the most common causes of death among the elderly and contributes to morbidity and disability associated with many chronic illnesses that are common in this age group. The health benefits of smoking cessation for the elderly have been clearly demonstrated. However, few studies have analyzed the relationship between health and smoking by considering the following many factors, especially among disabled people. In this study, we discuss the impacts of many factors on smoking among disabled people. Adults with disabilities are more likely to smoke than their peers. Public health agencies and practitioners should consider what reasonable adjustments may need to be made to policies and interventions to ensure that they are effective for adults with disabilities.

• Journal of the Korean Institute of Gas
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• v.27 no.4
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• pp.19-26
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• 2023

Earthquakes are one of the most important disasters affecting underground structures. Urban gas underground pipes may cause safety problems of structures in the event of an earthquake. Since Korea began digital observation, the number of earthquakes has been steadily increasing. The seismic design standard for urban gas pipes was established in 2008, but it is difficult to estimate the impact of pipes in the event of an earthquake based on the installation of pipes. In this study, structural analysis was performed on PE (polyethylene pipe) pipes and PLP (polyethylene coated steel pipe) pipes, which are mainly used as buried pipes in Korea, according to environmental and pipe variables in the event of an earthquake. This study sought to find the variables of the most vulnerable buried pipe by modeling pipes through Computer Aided Engineering (CAE) and generating displacement on the ground. Through this study, it was confirmed that the larger the elastic modulus of the soil, the deeper the buried depth, the smaller the tube diameter, and the higher the pressure, the more PLP pipes are affected by earthquakes than PE. Based on these results, the vulnerable points of buried urban gas pipes are inferred and used for special inspections of buried pipes in the event of an earthquake.

• Journal of Digital Convergence
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• v.22 no.2
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• pp.1-9
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• 2024

The purpose of this study is to verify whether companies residing in industry-academic convergence zones designated by the government are achieving policy goals and to seek policy implications and directions for improvement through analysis. For the study, business activities targeting resident companies were divided into infrastructure, business content, management, and system aspects, and business performance indicators, resident company satisfaction surveys, and differences in sales increase between resident companies and non-resident companies were analyzed through t-test. Based on statistical analysis results, performance indicators, and corporate survey analysis results, we track joint industry-academia R&D projects to maximize the effectiveness for companies, develop and operate human resources management for teams, and provide financial support for ordinances of metropolitan local governments. Improvements such as stipulation, antenna facilities at the corporate research center, and improvement of the researcher's residential environment were suggested. This study is the first to quantitatively verify policy performance targeting companies residing in industry-academic convergence zones, a large-scale government project, and future follow-up research is needed, including analysis of policy effects based on various variables such as employment indicators and corporate financial indicators.