• Journal of the Korea institute for structural maintenance and inspection
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• v.4 no.3
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• pp.161-168
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• 2000

A series of in-situ inspection and measurements have been conducted to estimate rebar corrosion incidence of concrete bridges in Seoul metropolitan area. The objectives of this study were to obtain the fundamental data to analysis the causes of rebar corrosion and to establish the repair strategies of deteriorated concrete bridges due to corrosion. The results of this study had been analysed to identify the extent of chloride content and incidence of rebar corrosion by construction ages and by members. After measuring chloride content in concrete, it was concluded that about 76% of all tests on samples from concrete exceed the maximum acceptable limit to risk of chloride-induced corrosion. On the whole, slabs had the most highly chloride content. About 16% of the concrete bridges had a value lower than -350mV (vs. CSE), so it could concluded that the excessive chloride content and carbonation were a major causes of rebar corrosion. Concrete member which carbonation depth penetrates toward rebar was 39% among all tests on samples. The major causes of rebar corrosion were highly chloride content 50%, concrete carbonation 38%, poorly visual condition 6% and etc, 6%.

• Journal of Korea Society of Industrial Information Systems
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• v.4 no.1
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• pp.102-109
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• 1999

In this paper, Electromagnetic scattering problem by a perfectly conducting strip grating with 2 dielectric layer on a grounded plane by incidence of a electric wave is analyzed by applying the PMM (Point Matching Method) known as a simple procedure. The scattered electromagnetic fields are expanded in a series of Floquet mode functions. The boundary conditions are applied to obtain the unknown field coefficients and the conducting boundary condition is used for the relationship between the tangential electric field and the electric current density on the strip When the incident angle is normal incidence the minimum value of the geometrically normalized reflected power according as relative permittivity is increased it should be noted that the value of the strip width gets moved toward high value. Them most energy by a normal incident wave is scattered in direction of the other angles except normal incident angle.

• Tuberculosis and Respiratory Diseases
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• v.85 no.4
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• pp.313-319
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• 2022

Environmental exposure to air pollution is known to have adverse effects on various organs. Air pollution has greater effects on the pulmonary system as the lungs are directly exposed to contaminants in the air. Here, we review the associations of air pollution with the development, morbidity, and mortality of pulmonary diseases. Short-and long-term exposure to air pollution have been shown to increase mortality risk even at concentrations below the current national guidelines. Ambient air pollution has been shown to be associated with lung cancer. Particularly long-term exposure to particulate matter with a diameter <2.5 ㎛ (PM_2.5) has been reported to be associated with lung cancer even at low concentrations. In addition, exposure to air pollution has been shown to increase the incidence risk of chronic obstructive pulmonary disease (COPD) and has been correlated with exacerbation and mortality of COPD. Air pollution has also been linked to exacerbation, mortality, and development of asthma. Exposure to nitrogen dioxide (NO₂) has been demonstrated to be related to increased mortality in patients with idiopathic pulmonary fibrosis. Additionally, air pollution increases the incidence of infectious diseases, such as pneumonia, bronchitis, and tuberculosis. Furthermore, emerging evidence supports a link between air pollution and coronavirus disease 2019 transmission, susceptibility, severity and mortality. In conclusion, the stringency of air quality guidelines should be increased and further therapeutic trials are required in patients at high risk of adverse health effects of air pollution.

• The Korean Journal of Emergency Medical Services
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• v.26 no.3
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• pp.201-208
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• 2022

Purpose: The purpose of this study is to analyze the current status of disasters and initial first aid in the construction industry, and to suggest the deployment of emergency medical technicians and reinforcement of first aid training in the construction industry. Methods: Among industrial accidents in 2020, the accident characteristics and initial first aid that occurred at construction sites were analyzed, and the emergency dispatch of 119 paramedics was analyzed through the SPSS method. Results: The incidence of serious accidents was high at small and medium-sized construction sites with less than 50 workers, and the incidence of falls was high, and there were few first responders who could provide first aid in the beginning. Therefore, it is necessary to improve first aid response capabilities at small construction sites. Conclusion: In order to improve the ability to respond to first aid at construction sites, it is necessary to deploy first responders and strengthen first aid education.

• Advances in aircraft and spacecraft science
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• v.9 no.2
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• pp.119-130
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• 2022

Supersonic projectiles like rockets, missiles, or aircraft find various applications in the field of defense. The shape of the wings is mainly designed as wedge shape or delta wings for supersonic vehicles. The study of supersonic flows over the wedges and flat plate delta wings around the large scale of incidence angle is considered in the supersonic projectile. In the present paper, the prime attention is to study the pressure at the nose of the plane wedge over the various Mach number and the various angles of incidence. Ghosh piston theory is used to obtain the pressure distribution analytically, and the results are compared with CFD analysis results. The wedge angle and Mach number are the parameters considered for the research work. The range of wedge angle is 50 to 250, and Mach number is 1.5 to 4.0 are considered for the current research work. The analytical results show excellent agreement with the CFD results. The results show that both the parameters wedge angle and Mach number are influential parameters to vary the static pressure. The static pressure increases with an increase in Mach number and wedge angle.

• Clinical and Experimental Pediatrics
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• v.51 no.7
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• pp.690-695
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• 2008

The age-specific anti-hepatitis A virus (HAV) seroprevalence rates in South Korea have changed markedly since the last 2030 years with an improvement in the socio-economic, housing, and environmental-sanitation conditions. These changes are characterized by very low anti-HAV seropositive rates among individuals less than 30 years of age; however, nowadays, most adolescents and young adults at an increased risk of developing symptomatic HAV infections. The Korea Center for Disease Control Sentinel Surveillance System has recently revealed an increase in the incidence of hepatitis A infection since 2001 and has revealed a potential endemic nature of the hepatitis A infection. Hepatitis A vaccines that were introduced in 1997 in Korea have made the current anti-HAV IgG positive rates in children (less than 10 years of age) approximately 50% of the rates observed in Seoul in 2006. However, in the same year, a few children were diagnosed as having anti-HAV IgG antibodies in Busan. This suggests the presence of some difference in the vaccination policy among doctors practicing in Seoul and Busan. Thus, the current recommendation of vaccinating 12-year-old child with HAV vaccination should be emphasized and a new strategy should be developed for the vaccination program to cater to the adolescents and young adults who are not immune, as well as for persons who are at a high risk for hepatitis A viral infection such as military personnel and hospital and day care center employees. Further, urgent hepatitis A vaccinations are also needed in patients with chronic liver diseases.

• Journal of Ocean Engineering and Technology
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• v.24 no.4
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• pp.8-12
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• 2010

The use of a tidal-current power system is one source of renewable energy that can minimize the environmental impact of power production and offer many other advantages compared to conventional energy sources. Unlike other energy production approaches, rate of energy production can be precisely predicted and the operational rate is very high. The performance of the rotor, which has a vital role in energy production using tidal currents, is determined by various design factors, and it should be optimized for the specific ocean environment in the field. The horizontal-axis turbine is very sensitive to the direction of flow, and flow direction changes due to rise and fall of the tides. To investigate the performance of the rotor considering the interaction problems with incidence angle of flow, a series of experiments were conducted, and a 3D CFD model was designed and analyzed by ANSYS CFX. The results and findings are summarized in the paper.

• Parasites, Hosts and Diseases
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• v.57 no.4
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• pp.329-339
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• 2019

Indonesia and South Korea have become inseparable in various respects since the 2 countries established diplomatic relation in 1973. Indonesia is a tropical region that stretches across the equator, comprised of 5 main islands (Java, Kalimantan, Sumatra, Sulawesi, and Papua) and 4 archipelagoes (Riau, Bangka Belitung, Nusa Tenggara, and Maluku). As most population of Eastern Indonesia (Sulawesi, Papua and Nusa Tenggara & Maluku) live in poor areas, it is expected that there will be many parasites. Nevertheless, little is known about the status of parasites in Indonesia. This study examines the prevalences of malaria and lymphatic filaria, which are prevalent in Indonesia, as well as those of soil-transmitted-helminths (STH). As a result, the Plasmodium falciparum and P. vivax case loads are almost equal. The current prevalence of P. vivax is uniformly low (<5%) in all age groups and annual parasite incidence (API) showed decreasing tendency as 0.84 per 1,000 population in 2016. However, more than 65 million people still live in malaria epidemic regions. Lymphatic filariasis remains an important public health problem and 236 cities were classified as endemic areas in 514 cities/districts in 2017. It is difficult to ascertain the current prevalence rate of STH in Indonesia, although West Sumba and Southwest Sumba in East Nusa Tenggara reported prevalence rate of more than 20%. The study also considers the (sero) prevalences of other parasites identified in Indonesia. This report should be useful not only to parasitologists but also to travelers and people with business in Indonesia.

• Biomedical Science Letters
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• v.29 no.4
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• pp.355-362
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• 2023

This study aimed to determine whether smoking affects the metabolic syndrome and its components through long-term follow-up. Of the 10,030 cohort subjects in the community-based Korean Genome and Epidemiology Study (KoGES) from 2001 to 2018, 2,848 people with metabolic syndrome and 4,854 people with insufficient data for analysis were excluded for this study. The study population comprised 2,328 individuals (1,123 men, 1,205 women) who were eligible for inclusion. The mean age of the participants was 49.2±7.5 years, and 21.9% were current smoker. In log rank test, current smoker had a significantly higher cumulative incidence of metabolic syndrome compared with non smoker (P<0.001). In the Cox proportional hazards model adjusted for key variables, metabolic syndrome (hazard ratio [HR] 1.57, P<0.001), high fasting glucose (HR 1.40, P<0.01), hypertriglyceridemia (HR 1.60, P<0.001), low HDL-cholesterol (HR, 1.30, P<0.01), and abdominal obesity (HR 1.32, P<0.01) in current smoker compared with non smoker were statistically significant, respectively, but not hypertension (HR 1.00, P>0.05). After adjustment for confounders, the time (P-time<0.001) and group (P-group<0.001) effects on metabolic syndrome score change were statistically significant. Furthermore, the interaction analysis of time and smoking group on the change in metabolic syndrome score was statistically significant (P-interaction<0.001). In long-term follow-up, smoking worsens metabolic syndrome.

• Journal of the korean academy of Pediatric Dentistry
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• v.48 no.4
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• pp.376-383
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• 2021

The aim of this study was to determine the prevalence and incidence and evaluate the current status of dental treatment of Amelogenesis imperfecta (AI) and Dentinogenesis imperfecta (DI) in South Korea. The data was based on National Health Insurance Service (NHIS)-National Sample Cohort Database (2002 - 2015) and Jeonbuk National University (JBNU) Dental Hospital (2011 - 2020). The NHIS data analysis showed prevalence of AI and DI were 11.6 and 2.4 per 100,000 people, respectively. The annual incidence of AI and DI for 2013 - 2015 were 2.2 and 0.5 per 100,000. There were no statistically significant differences regarding the number of visits, the reimbursable cost among AI, DI patients and others. In the patient analysis of the JBNU dental hospital, proportion of the reimbursable and non-reimbursable cost for AI patients were 12.1% and 87.9%, while DI patients accounted for 18.6% and 81.4%.