• Geophysics and Geophysical Exploration
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• v.12 no.1
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• pp.56-68
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• 2009

Ongoing and extensive urbanisation, which is frequently accompanied with careless construction works, may threaten important archaeological structures that are still buried in the urban areas. Ground Penetrating Radar (GPR) and Electrical Resistivity Tomography (ERT) methods are most promising alternatives for resolving buried archaeological structures in urban territories. In this work, three case studies are presented, each of which involves an integrated geophysical survey employing the surface three-dimensional (3D) ERT and GPR techniques, in order to archaeologically characterise the investigated areas. The test field sites are located at the historical centres of two of the most populated cities of the island of Crete, in Greece. The ERT and GPR data were collected along a dense network of parallel profiles. The subsurface resistivity structure was reconstructed by processing the apparent resistivity data with a 3D inversion algorithm. The GPR sections were processed with a systematic way, applying specific filters to the data in order to enhance their information content. Finally, horizontal depth slices representing the 3D variation of the physical properties were created. The GPR and ERT images significantly contributed in reconstructing the complex subsurface properties in these urban areas. Strong GPR reflections and highresistivity anomalies were correlated with possible archaeological structures. Subsequent excavations in specific places at both sites verified the geophysical results. The specific case studies demonstrated the applicability of ERT and GPR techniques during the design and construction stages of urban infrastructure works, indicating areas of archaeological significance and guiding archaeological excavations before construction work.

• Journal of dental hygiene science
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• v.13 no.4
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• pp.518-527
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• 2013

In 2011, South Korea's Ministry of Health and Welfare started a national tooth brushing room program without a pilot project. This study aimed to assess the effect of the implementation of this program in Gangneung, Korea. One-year outcomes of oral health behavior and self-reported oral symptoms in the study group after installation of the tooth brushing room were evaluated and compared with those of the control group using chi-square test. The prevalence rate of good self-rated oral health in grade 1-3 students increased from 35.7% immediately after installation to 48.9% after 6 months (p=0.031) compared to 37.3% in the control group (p=0.051). Immediately after installation of the tooth brushing room, 53.5% of grade 1-3 students in the study group brushed their teeth every day, but after 6 months, only 35.5% of students brushed daily (p<0.001) compared to 28.6% in the control group (p=0.007). The prevalence rate of bad breath in grade 1-3 students was 26.2% for the study group immediately after installation compared to 25.5% in the control group (p=0.065), but it declined 16.5% after 6 months (p=0.055). The prevalence rate of bad breath in grade 4~6 students was 14.7% for the study group after 6 months compared to 25.3% in the control group (p=0.016). We recommend the creation of a healthy school environment through a school-based tooth brushing program under the active supervision of classroom teachers and the continuous monitoring of program processes in order to promote children's oral health.

• Journal of dental hygiene science
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• v.13 no.4
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• pp.471-479
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• 2013

This study is trying to grasp the stress of the male high school students and the correlation between the stress according to the academic and economic level and oral parafunctional habits, emphasizing the need for the education of oral parafunctional habits, providing the basic data in order to accomplish correctly until the oral health of the oral maxillofacial region. From May 2013 till July 2013, a self administered survey was conducted by the selected by convenience sampling from subjects of 1, 2 grade of two high school located in Chungnam, Korea. The study results were as follow: 1) Among five areas of stress, the stress of school life was the highest as 2.11 points and the stress of home problem was the lowest as 1.51 points; 2) the stress by class showed that grade 2 was higher than grade 1 in all areas. The stress of the school life (2.21) (p<0.01), interpersonal relationship (p<0.01), and own problem (p<0.05) showed the significant difference; 3) The significance analysis results between the five areas of stress according to the stress of latent variable and the oral parafunctional habits all showed the significant difference (p<0.001). The correlation between the stress and the oral parafunctional habits showed a weak negative correlation as -0.30, and the stress of the school life, own problem, environment problem, and interpersonal relationship showed very strong correlations more than 0.7; 4) Fit measures test result of stress, academic level, and family economic level model all showed more than 0.9 in good of fit index, adjusted goodness of fit index, normed fit index and root mean square residual and root mean square error of approximation values is all estimated less than 0.1, so it showed good model. From this study, it can be concluded that there is the correlation between stress and oral parafunctional habits.

• Journal of dental hygiene science
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• v.17 no.6
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• pp.463-471
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• 2017

The purpose of this study was to examine the causes of career interruptions among dental hygienists, institutional measures required for their long service and ways of creating a stable employment culture for them in determine how to resolve labor shortage, create stable jobs, and step up the reemployment of idle manpower. In addition, the following suggestions are made for the establishment of a stable employment culture for dental hygienists by analyzing related literature, research materials, and information such as forums for establishing appropriate jobs for female dental workers. First, a system should be set up to prevent career interruption among dental hygienists. The work environment should be improved to prevent career breaks, and the wages, working hours, and working style should be efficiently structured to maintain the tenure of employees. Second, a plan should be devised to make use of idle manpower, and a variety of necessary programs should be developed. With respect to regular working hours, the time conversion system should be used, which reduces the amount of time one would want to work while receiving a national subsidy. Third, dental hygienists working in different occupations for marriage, childbirth, childcare, school and personal hygiene should make a way to return to the dental system immediately when they want. Fourth, the government should take institutional measures and offer down-to-earth support and benefits for women consideration their social characteristics to guarantee a balance between work and childcare.

• Clean Technology
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• v.17 no.4
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• pp.379-388
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• 2011

The purpose of this study was to investigate the concentration levels, distribution characteristics and blood concentration of Polycyclic Aromatic Hydrocarbons (PAHs) at ambient air in Industrial Complex Area. The samples were collected at 4 sites in Industrial Complex Area and its vicinities. The result indicated that there was the difference of PAHs concentration as followed local characteristics. The level of average concentration of PAHs in the air in Industrial Complex Area was $14.52{\sim}193.48ng/m^3$. The level of average concentration of six materials with possibility of cancer creation was $1.65{\sim}13.44ng/m^3$. The concentrations of PAHs were generally low, but Jechul-dong is considered an area where consistent monitoring of PAHs is required. In addition, benzo(a)pyrene was detected in every atmospheric sample, however the concentration was not high. The level of concentration of benzo(a)pyrene in the air in the Jechul-dong was $2.89ng/m^3$. But, the concentration of the PAHs in Jechul-dong showed that the Benzo(a)pyrene concentration is above $1ng/m^3$ of air quality standard(EU). The results of the concentration level of PAHs in the blood from 240 persons who were exposed directly were surveyed, it was $1.12{\sim}11.45ng/m^3$ for man and $1.20{\sim}26.89ng/m^3$ for woman. It was indicated that the difference between the genders was very little. The accumulation inside human was anticipated as the PAHs concentration in the blood for the aged was very high. Industrial Complex Area and its vicinities are an area which has been greatly influenced by PAHs and environmental contaminants. It is necessary to control the emission sources of PAHs and to construct an observation system at Industrial Complex Area from now on. It is time to reduce the risk factors for health and environmental disease to protect the health of resident in Industrial Complex Area and its vicinities.

• Journal of dental hygiene science
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• v.16 no.2
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• pp.183-192
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• 2016

A total of 228 dental hygienists working in dental hospitals and clinics in the Busan and Gyeongnam areas were surveyed between August 1, 2015, and October 15, 2015. The factors influencing infection control awareness and implementation levels among the dental hygienists were investigated to prepare basic data with the goal of establishing guidelines for systemic infection control. Treatment preparation support for infection control positively correlated with equipment and facility support (r=0.4343, p<0.01), treatment skill and information support (r=0.231, p<0.01), infection control education support (r=0.266, p<0.01), infection control awareness (r=0.354, p<0.01), and infection control implementation levels (r=0.442, p<0.01). Equipment and facility support positively correlated with treatment skill and information support (r=0.418, p<0.01), infection control education support (r=0.422, p<0.01), infection control awareness (r=0.404, p<0.01), and infection control implementation levels (r=0.454, p<0.01). Infection control education support positively correlated with infection control awareness (r=0.348, p<0.01) and infection control implementation levels (r=0.405, p<0.01). Infection control awareness positively correlated with the infection control implementation level (r=0.879, p<0.01). The factors influencing the awareness of infection control include treatment preparation support, equipment and facility support, treatment skill and information support, and infection control education support. The influencing the infection control implementation level include treatment preparation support, equipment and facility support, infection control education support, and treatment skill and information support. To enhance the awareness of infection control and implementation levels amongdental hygienists, an infection control system must be established and implemented A rigorous system for evaluating dental clinics must also be established to ensure an ideal dental treatment environment and to protect patients' health and safety.

• Clean Technology
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• v.2 no.1
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• pp.96-108
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• 1996

$NO_x$ is mainly emitted from mixed acid pickling process in the stainless industry and its impact to the environment has been worried over. This study which may be considered as one of the development of clean technologies, differing from the traditional end pipe technology is about how to reduce $NO_x$ emission through the modification of corresponding process. This study consists of two parts. First, the influence of various reaction parameters in a acid pickling process on $NO_x$ emission was investigated. Second, the influence of hydrogen peroxide on $NO_x$ formation, which is known as inhibitor of $NO_x$ emission, was investigated. Major findings in this study are as follows. The important reaction parameters which have a great influence on $NO_x$ emission are the reaction temperature and the concentration of fluoric acid. The concentration of nitric acid, some of which results in $NO_x$ compound is not as important as the concentration of fluoric acid. Synthetic mixed acid of nitric acid and fluoric acid itself in absent of pickling plate contributed the $NO_x$ emission, however, its impact was negligible in terms of quantity. The addition of hydrogen peroxide to the acid pickling process significantly contributed to the reduction of $NO_x$ emission and successfully achieved 80% reduction of $NO_x$ emission at the condition of $9.51{\times}10^{-2}mole\;hydrogen\;peroxide/m^2$ pickling area. This result was compared to literature value from Avesta steel process, indicating a sixth of hydrogen peroxide addition of Avesta's in achieving a same amount of $NO_x$ reduction. The region of the economic hydrogen peroxide addition per unit area of plate to be pickled from the result of this study was established.

• Clean Technology
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• v.18 no.2
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• pp.200-208
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• 2012

This study was performed to prevent the health damage of environmental contaminants in Industrial Complex Area. And, this study aimed to identify the concentration levels and distribution characteristics of environmental contaminants and Polycyclic Aromatic Hydrocarbons (PAHs) at soil in Industrial Complex Area and control area. The concentration of the soil pollution standard such as the heavy metals in the soil, VOCs, PAHs, and PCB were measured and analyzed using the soil specimens in the Industrial Complex Area and control area. Soil specimens from the Industrial Complex Area (the direct exposure area) and the control area were surveyed. Songdo-dong, Haedo-dong and Jechul-dong, which are in the direct exposure area and near the emission source, showed relatively high concentrations of contaminant materials when compared with Jangki-myeon, which is far off and in the control area. The concentration of zinc was 20.8-58.9% of the level of concern (300 mg/kg) in the 1st region, which is a relatively high concentration. The concentration of fluoride was under the standard in every region, but it was about 74% of the level of concern (400 mg/kg) in the 1st region. It is recommended that controlling fluoride emissions is necessary. Levels of organic phosphate, phenol, and VOCs like benzene, toluene, ethylbenzene and xylene were under the detection limit of the analysis instruments. The concentration of TPH was high in Songdo-dong. The concentration of contaminants in Jechul-dong was high. In addition, it was observed that the level of soil contamination changed depending on the distance from the emission source. The concentration of PAH compounds in the soil was 18.71-1744.59 ng/g, and the concentration of six potential cancer-causing PAH materials was 6.54-695.94 ng/g. The highest concentration was in Songdo-dong. The PAH concentration in the direct exposure area near the complex was relatively high compared to the indirect exposure area.

• Journal of dental hygiene science
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• v.15 no.3
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• pp.265-271
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• 2015

This study has an objective not only to be helpful to the understanding about students' career and employment preparation by investigating the present conditions which are related with vocational consciousness and job values of dental hygiene department graduating students. Study subjects were 350 female graduating students in 3-year-course College, dental hygiene department at five areas of Seoul, Gyeonggi, Gangwon and Gyeongnam. Data were analyzed using IBM SPSS Statistics ver. 19.0. Regarding job values, job prospect of dental hygienist is a little developmental (55.2%) and institution hoping to work is dental clinic (43.2%), reasons for employment in major area are good wage and working environment (24.0%). And regarding opinion about job, dental hygienist job is a measure for living income (69.7%). Regarding job selection conditions, 35.0% subjects replied good human relationship. In the questionnaires regarding professional job in vocational consciousness category, results showed high percentages in that 'the occupation is a job in charge of oral health improvement'; regarding academic area, 'scaling should be done better than dentist'; regarding human relationship, 'harmony between colleagues is closely related with job efficiency'; regarding work ethics, 'development of dental hospital (clinic) and dental hygienist is correlated.' In vocational consciousness of study subjects, higher major satisfaction showed significant differences in professional job consciousness and work ethics consciousness (p<0.05) and the correlation results in vocational consciousness areas showed all statistically significant correlations (p<0.01). In case that the characteristic in one type is higher among 4 types, all other types showed high characteristics and also showed high general vocational consciousness.

• Journal of Life Science
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• v.21 no.4
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• pp.549-553
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• 2011

This study was performed to determine whether or not urinary 1-hydroxypyrene (1-OHP) levels can be accurately detected by our 1-OHP-detecting $TiO_2$-Bead-HPLC assay that we developed based on the molecular imprinting method. Our method showed a variation coefficient of 4.97% and a between-day variation coefficient of 4.43%, suggesting that this may be a very stable method. In addition, the recovery rate of 1-OHP from a mixture of 1-OHP and similar substances using our $TiO_2$-Bead-HPLC method was estimated to be 105.6%. The correlation coefficient between the conventional enzyme-HPLC method and this new method was 0.74 (p<0.01) when the urine samples were tested. Based on this result, it is conceivable that our method could be a useful technique for measuring urinary 1-OHP levels. Moreover, our method has some advantages of being easier and less expensive than the conventional method. The results of this study suggest that our method can facilitate the development of a urine 1-OHP sensor using $TiO_2$-coating beads and that development of beads by molecular imprinting can be applied to analysis of chemicals other than 1-OHP.