• Parasites, Hosts and Diseases
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• v.55 no.5
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• pp.523-532
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• 2017

A field survey studying intestinal parasites in humans and microbial pathogen contamination at environment was performed in a Laotian rural village to identify potential risks for disease outbreaks. A parasitological investigation was conducted in Ban Lak Sip village, Luang Prabang, Lao PDR involving fecal samples from 305 inhabitants as well as water samples taken from 3 sites of the local stream. Water analysis indicated the presence of several enteric pathogens, i.e., Aeromonas spp., Vibrio spp., E. coli H7, E. coli O157: H7, verocytotoxin-producing E. coli (VTEC), Shigella spp., and enteric adenovirus. The level of microbial pathogens contamination was associated with human activity, with greater levels of contamination found at the downstream site compared to the site at the village and upstream, respectively. Regarding intestinal parasites, the prevalence of helminth and protozoan infections were 68.9% and 27.2%, respectively. Eight helminth taxa were identified in fecal samples, i.e., 2 tapeworm species (Taenia sp. and Hymenolepis diminuta), 1 trematode (Opisthorchis sp.), and 5 nematodes (Ascaris lumbricoides, Trichuris trichiura, Strongyloides stercoralis, trichostrongylids, and hookworms). Six species of intestinal protists were identified, i.e., Blastocystis hominis, Cyclospora spp., Endolimax nana, Entamoeba histolytica/E. dispar, Entamoeba coli, and Giardia lamblia. Questionnaires and interviews were also conducted to determine risk factors of infection. These analyses together with a prevailing infection level suggested that most of villagers were exposed to parasites in a similar degree due to limited socio-economic differences and sharing of similar practices. Limited access to effective public health facilities is also a significant contributing factor.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.6
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• pp.94-104
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• 2010

The capacity of highway is restricted and traffic congestion is caused by increasing traffic demand. Also, greenhouse gases are increased by traffic congestion. CDM (Clean Development Mechanism) is an idea of interest to reduce greenhouse gases. However, CDM's cases applied in traffic field are rare. Thus, it is necessary that methodology to reduce greenhouse gas should be developed and applied to CDM. A methodology for identifying greenhouse gas emissions was developed in this paper. This methodology was developed on the basis of baseline methodology registered at UN. Travel time and speed in the conventional traffic condition and in the automated traffic condition are compared by BPR function. The calculated speed applied to emission factor equation and then $CO_2$ emissions was calculated. A simulation was executed to evaluate the validity of the developed methodology. In the result, advanced vehicle's $CO_2$ emissions are more than conventional vehicle's $CO_2$ emissions in the stable flow condition. However, advanced vehicle's $CO_2$ emissions are less than conventional vehicle's $CO_2$ emissions in the unstable flow condition. It is assure that capacity of highway is enhanced and efficiency of highway is improved by adopting advanced safety vehicle in the smart road.

• Journal of Korean Society of Forest Science
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• v.84 no.1
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• pp.1-9
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• 1995

This study investigates the collective aspects of hunting motivation and hunters' attitude toward natural environment. Data were collected from three different types of respondents : 148 hunters who purchased hunting license between November 1992 and March 1993 in Cholla Province. 120 university students and 260 Suwon residents. The 26 items out of 90 items were selected to develop an attitude scale toward natural environment. Results of ANOVA revealed that there were significant differences among five groups(hunters, urban residents and students from 3 major fields) in terms of their attitude values. Hunters' attitude value toward natural environment was the highest among five different types of respondents. Two major motives for hunting participation are 'exercise' and 'like out-of-doors'. Factor analysis presents eight motivational dimensions underlying hunter's involvement in the activities: 1)stewardship, 2)social contact, 3)show-off, 4)sportsmanship, 5)like to kill, 6)recreation/relax, 7)economic gain, and 8)being alone. The correlation between the motivational factor of 'economic gain' and the attitudinal item of 'relationship between man and nature' was negative(r=-0.28). There is a positive correlation(r=0.24) between the motivation of 'being alone' and the attitude of 'needs for natural environment'. These relationships indicate that individual's attitude value decreases when one perceives nature as economic goods, while it increases when one visits nature to relieve stress and to develop self-esteem.

• Journal of Microbiology and Biotechnology
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• v.17 no.9
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• pp.1437-1444
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• 2007

A response surface model was developed for predicting the growth rates of Staphylococcus aureus in tryptic soy broth (TSB) medium as a function of combined effects of temperature, pH, and NaCl. The TSB containing six different concentrations of NaCl (0, 2, 4, 6, 8, and 10%) was adjusted to an initial of six different pH levels (pH 4, 5, 6, 7, 8, 9, and 10) and incubated at 10, 20, 30, and $40^{\circ}C$. In all experimental variables, the primary growth curves were well ($r^2=0.9000$ to 0.9975) fitted to a Gompertz equation to obtain growth rates. The secondary response surface model for natural logarithm transformations of growth rates as a function of combined effects of temperature, pH, and NaCl was obtained by SAS's general linear analysis. The predicted growth rates of the S. aureus were generally decreased by basic (pH 9-10) or acidic (pH 5-6) conditions and higher NaCl concentrations. The response surface model was identified as an appropriate secondary model for growth rates on the basis of correlation coefficient (r=0.9703), determination coefficient ($r^2=0.9415$), mean square error (MSE=0.0185), bias factor ($B_f=1.0216$), and accuracy factor ($A_f=1.2583$). Therefore, the developed secondary model proved reliable for predictions of the combined effect of temperature, NaCl, and pH on growth rates for S. aureus in TSB medium.

• Tunnel and Underground Space
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• v.25 no.2
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• pp.155-167
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• 2015

The thermal-hydrological-mechanical (T-H-M) behavior of rock mass surrounding a high-temperature cavern thermal energy storage (CTES) operated for a period of 30 years has been investigated by TOUGH2-FLAC3D simulator. As a fundamental study for the development of prediction and control technologies for the environmental change and rock mass behavior associated with CTES, the key concerns were focused on the hydrological-thermal multiphase flow and the consequential mechanical behavior of the surrounding rock mass, where the insulator performance was not taken into account. In the present study, we considered a large-scale cylindrical cavern at shallow depth storing thermal energy of $350^{\circ}C$. The numerical results showed that the dominant heat transfer mechanism was the conduction in rock mass, and the mechanical behavior of rock mass was influenced by thermal factor (heat) more than hydrological factor (pressure). The effective stress redistribution, displacement and surface uplift caused by heating of rock and boiling of ground-water were discussed, and the potential of shear failure was quantitatively examined. Thermal expansion of rock mass led to the ground-surface uplift on the order of a few centimeters and the development of tensile stress above the storage cavern, increasing the potential of shear failure.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.9 no.1
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• pp.41-55
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• 1999

In order to evaluate the effects of knowledge, attitude and practice on noise-induced hearing loss or hearing threshold level, questionnaire survey was performed and hearing thresholds of 1 kHz and 4 kHz were measured on 1,040 subjects with workers exposed to noise, safety and health officers. industrial hygienists, analysts rind office workers. The results were as follows ; 1. The following 6 factors were obtained by factor analysis and factor rotation of 30 questionnaire of knowledge, attitude and practice about noise; knowledge of noise (F1), concern of hearing protective devices (F2), concern of noise induced hearing loss (F3), concern of noise level and hearing impairment (F4), concern of noise in workplace (F5) and recognition of noised-induced hearing loss (F6). 56.1% of variance was explained by 6 factors. 2. Significant variables influencing knowledge, attitude and practice about noise were education level and age in F1, personal protective devices (PPE) and education level in F2, age and education level in F3, education level, age and sex in F4, PPE, education level, age and work duration in F5, and work duration and PPE in F6. 3. Hearing thresholds of 4 kHz were significantly higher in workers exposed to noise than that of in the other subjects and tended to be higher in industrial hygienists, safety and health officers and analysts than that of the office workers. 4. Significant variables influencing hearing thresholds of 1 kHz were age, education level, F5 and F6 in workers exposed to noise, and F1 in industrial hygienists. 5. Significant variables influencing hearing thresholds of 4 kHz were age, F6, sex, work duration, F1, F5, F2 and F3 in workers exposed to noise, F1 and age in safety and health officers, and F6, sex and F4 in industrial hygienists. With the above results, it suggested that workers exposed to noise be needed the education of knowledge, attitude and practice about noise in hearing conservation program for the prevention of noise induced hearing loss. Also, it suggested that health managers in workplace be needed countermeasures to prevent hearing loss although they are intermittently exposed to noise.

• Tuberculosis and Respiratory Diseases
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• v.62 no.1
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• pp.27-32
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• 2007

Background: This study evaluated the accuracy of smoking habit from the data obtained from the medical records of lung cancer patients against the data obtained form face-to-face interview questionnaires Methods: The smoking habits of 225 lung cancer patients were categorized into never smoked, ex-smoker and current smoker in face-to-face interview questionnaire and medical record taken at the time of admission for a diagnosis. The overall agreement between two sources was evaluated. The factors affecting the disagreement between two sources and the level of data omission of the smoking habits in medical records were analyzed suing multiple logistic regression. Results: The smoking habit between two sources showed moderate overall agreement(Kappa $({\kappa})=0.60$). The lowest agreement was observed in the ex-smokers(${\kappa}=0.49$). Multivariate analysis revealed an age of 65 or older to be a statistically significant factor associated with the increasing disagreement risk compared with those 64 or younger (OR 3.02; 95% CI 1.58-5.80). The omission rate of smoking habits in the medical records was 18.2%. Adenocarcinoma was shown to be a statistically significant factor of associated with an increasing omission rate compared with squamous cell carcinoma (OR 3.00; 95% CI 1.19-7.59). Conclusion: The smoking habits obtained from medical record moderately reflect their true behavior. However, the smoking habit data from medical record should be used with caution when being used in a clinical study or cohort study of lung cancer.

• Journal of the Korean Geosynthetics Society
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• v.19 no.1
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• pp.75-82
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• 2020

There have been often cases of collapse for geogrid reinforced soil (GRS) retaining wall. Hence, social interest in the reinforcement and restoration of the collapsed GRS wall is increasing day by day. However, there are only few researches. For this reason, a series of numerical analyses using the Plaxis 2D program was conducted in this study to analyze the suitable reinforcement methods that can be applied on the existing damaged GRS wall caused by overturning of the modular blocks facing and the surface settlement at the backfill as the results from the design failure. The restoration plan used in this study is composed of two cases: (Case 1) soil nailing reinforcement and reinforced concrete (RC) wall facing construction on the existing damaged GRS wall; and (Case 2) removal of the entire damaged GRS wall and then reconstruction. The results on the internal stability of the GRS wall show that Case 1 obtained a greater safety factor than Case 2 for tensile force while Case 2 had a greater safety factor than Case 1 for pullout failures. Case 1 was found to be more stable than Case 2 in terms of the global slope safety by shear strength reduction method and the external deformation behavior by numerical analysis. In this study, the existing damaged GRS wall which was reinforced using Case 1 method shows more stable external behavior.

• The Mathematical Education
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• v.42 no.3
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• pp.295-302
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• 2003

The purpose of this study is to make more reliable researches on the tendency of shirking from the mathematics by including those of the students in the other country, and there are a series of researches such as 'math-camp to raise the mathematical tendency of the students who make little progress in the study', 'establishment of factors causing the shirking tendency from the mathematics and development of the analyzing instruments for it' and 'study on the preference to each category of the school mathematics.' For this purpose, I used a test developed by the shirking tendency research team. I compared the average score and standard deviation between the Korean and the Australian students. As for the average score, that of the Australian elementary school students is about one point higher than the Korean students, and there was no remarkable difference in the deviation. Comparing the math-shirking tendency of the two groups, they show higher shirking tendency in the aspects of emotional and mathematical recognition that belong to the psychological and environmental sphere. And, as for an extent of association in difficulties according to each school grades, its degree of the Australian students is comparatively lower than that of the Korean students, therefore, the shirking tendency of the Australian students is intermediate level whereas that of the Korean students is the lowest. They show us a peculiar result in teacher factor. It is noteworthy in that the Korean students show a positive reaction in that factor, however, the Australian students show a comparatively weak reaction. It might be caused by a cultural difference. I also have compared the accumulated percentage according to each shirking tendency factors. It will not only be very efficient for teachers to establish a teaching plan but also a good data to understand the shirking tendency of each student. This will be a very good data for the planners of teaching policy to remedy the causes of shirking tendency. And, it will also be used effectively to write a new textbook. It has been uncommon that a psychological test is used in the research for the improvement of teaching and learning mathematics. In this aspect, I am sure that this study including the preceding research will be a good in studying the shirking tendency factors by using a psychological test. I believe that this research will be a help to grasp the outline of the shirking tendency and I will have to try continuously to make it be a reasonable and reliable study.

• Journal of the Korean Geographical Society
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• v.29 no.2
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• pp.202-215
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• 1994

This research aims to introduce the theoretical basis of the studies of tourism resources, by review the research trends of tourism resources in the geography field. The geographical approaches to tourism resouces can be subdicided into 3 categories according to the subject. First, the classification of tourism resource types and the approach on the spatial distribution may be enumerated. This subject has been the object of the most interest and discussion to the geographers for tourism up to now. And from the viewpoint of contents, it has been developed by classifying the types of tourism resoures, which is based on the establishment of the range and standard of tourism resources and the spatial classification of types based on the distribution feature of the area. Second, the approach about cognition, preference and interpretation on the tourism resources as the background to induce tourism phenomenon and decide the tourism destination. Judging from the fact that most of this subject is starting from the behavioural study and that the right understanding and interpretation of tourism resource is the important factor to decide the preference degree of tourists, we have to have much interest about the field of tourism geoaraphy. Third, the development of tourism resources which is showing the active study recently and its influence and effect attendant upon it may be enumerated. Today, as the economic value of tourism is become important internationally, tourism resources are recognized as the important factor to induce the industrialization of tourism. And in the series of analytical studies related to it the interest has been transferred from the economic benefit analysis attendant upon tourism development including tourism resource and to the cultural, educational, environmental and psychological influence, etc. As the result of composite examination, for the geographical studies about tourism resources, the spatial scale and the contents are being subdivided and specialized. And in the side of subject and method of study, it is developing into the positive study based on the concrete data and the measuring and analytical frame.