• 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.

• Journal of Korean Society on Water Environment
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• v.21 no.1
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• pp.52-58
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• 2005

The assessment on characteristics of hydraulic behavior and water quality variations of underground reservoirs of buildings were studied. Firstly, it was thought that underground reservoir capacities($m^3$) of buildings should be not determinated by the uniform and same methods but be estimated on the basis of the dwelling areas on dominated households and their residential characteristics, because these characteristics influence significantly on actual water usages and patterns of buildings. Secondly, it was likely that the average reduction rate of residual chlorine in underground reservoirs were affected from the their capacities, because the average reduction rate of residual chlorine in underground reservoirs under $1,000m^3$ was 43 percent, on the other hand, that rate of underground reservoirs over $1,000m^3$ was 60 percent. Thirdly, through the field investigation, the retention time of drinking water in underground reservoirs were in the range from 0.3 day to 3.9 day. In addition to, the average reduction rate of residual chlorine were depended largely on the retention time of drinking water. When the retention time was under 24 hours, the average reduction rate of residual chlorine was 45 percent, and in case of over 24 hours, was 49 percent. Fourth, water level in underground reservoirs was averagely varied in the range from 0.1 m to 2.65 m at the height of underground reservoirs. If considered actual height of underground reservoirs, 37.6 percent of the height of underground reservoirs was only used. Consequently, the frequency of the inflow and outflow of drinking water in underground reservoir were very increased, and had an effect on the reduction of residual chlorine. Lastly, the investigations on hydraulic structure characteristics of underground reservoirs inside showed the locations of inflow and outflow of drinking water almost were in the opposite direction. And some buildings had several baffles in the middle. Nevertheless, their installations had no beneficial for the improvement of water quality.

• Korean Journal of Soil Science and Fertilizer
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• v.22 no.2
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• pp.122-126
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• 1989

The study was performed to examine varietal differences of wilting injury in terms of the root developing system and root activity. The field survey was conducted at the farmer's, and the experimental fields. The experimental investigation was done at different growth stage of rice plant in the sand culture condition. The results were summarized as follows: 1. The T/R ratio of healthy plants was greater than that of the wilted plants in Yushin. 2. Regardless of plant parts, the root activity of the wilted plants decreased in Yushin. The T/R ratio of Yushin tended to increase at the vegitative stage while the Photosynthate distribution to root decreased at the later stage. 3. The root activity and the plant growth rate were higher at vegetative growth stage, while the root activity at reproductive stage decreased. 4. The root activity of Milyang 23, which has relatively less injury of wilting, did not significantly differ between the wilted and the healthy plants. The root was thick and T/R ratio was low.

• Fire Science and Engineering
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• v.20 no.3 s.63
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• pp.107-112
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• 2006

The purpose of this study is to help the education of fire safety of technical high schools through the investigation of skills club students's recognition on fire safety in Seoul city. To achieve the purpose, 56 skills students who going to skills competition were surveyed for 3days from Jun. 19 to 21, 2006. The Results of this study are as follows ; First, a large numbers of students in technical high school placed low value on the importance of safety in life, and fire safety was very important, however, lower than structural safety. Second, the education of fire safety was arranged by school authorities, carried out only by the half of these school. It was necessary that the specific education of fire safety for major and skills competition was hosted by a department. Third, it was necessary that the system all accidents were certainly reported by the related student and the method prevented a recurrence. 4th, the field of fire safety in Industrial Introduction subject of national curriculum was satisfied by students. And if this subject revised, students wanted to extend the contents of fire safety and to orient to practical technique.

• Journal of the Korea Concrete Institute
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• v.25 no.6
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• pp.621-630
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• 2013

Several techniques for steel corrosion detection are proposed and HCP (half cell potential) technique is widely adopted for field investigation. If concrete has cracks on surface, steel corrosion is rapidly accelerated due to additional intrusion of chloride and carbon dioxide ions. This study is for an evaluation of HCP in cracked concrete exposed chloride attack. For this work, RC (reinforced concrete) beams are prepared considering 3 w/c ratios (0.35, 0.55, and 0.70) and several cover depths (10~60 mm) and various crack widths of 0.0~1.0 mm are induced. For 35 days, SST (salt spraying test) is performed for corrosion acceleration, and HCP and corrosion length of rebar are evaluated. With increasing crack width, w/c ratios, and decreasing cover depth, HCP measurements increase. HCP evaluation technique is proposed considering the effects of w/c ratios, crack width, and cover depth. Furthermore anti-corrosive cover depths are obtained through Life365 program and the results are compared with those from this study. The results shows relatively big difference in cracked concrete, however provide similar anti-corrosive conditions in sound concrete.

• Journal of Technologic Dentistry
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• v.22 no.1
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• pp.89-112
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• 2000

Although dental laboratory technicians are prone to be exposed to various work-related health hazardous materials such as dusts, chemicals, etc., the prevalence and nature of work-related health problems of them have not been a matter of great concern in the field of occupational health service in Korea. The purpose of the present investigation was to describe a collected profile of subjective health symptoms and their attributable factors in Korean dental laboratory technicians. A questionnaire listing five groups of health symptoms and five health symptom-related factors was mailed to randomly selected 1,900 dental laboratory technicians. Among them, 1,344 dental laboratory technicians filled out the questionnaires and returnde them. Five groups of health symptoms included musculoskeletal symptom, dermal symptoms, respiratory symptoms, eys symptoms, and ear symptoms. Five health symptom-related factors were occupational environment-related health risk factors, work history, health related habits and status, use of personal protective equipment and general characteristics. Detailed parameters of health risk factors were work posture, vibration, and chemical or physical hazards such as dust, fume, vapor, solvent, light, and noise for occupational environment-related factors; work place, area, number of employees, work hours, career, work part, and work load for work history; Broca's index, hours of sleep, eating, smoking, alcohol, exercise, health examination, and self assessed health status for health habits and status; face masks, goggles, and so on for use of personal protective equipment, and; age, sex, marital status, and education for general characteristics. Before the start of main survey, a pilot survey was carried out for validity and reliability tests of the questionnaire. All the data obtained were coded and analyzed with PC/SAS 6.12 program. The prevalence of health symptoms was the highest in musculoskelton (87.3%), and followde by eyes (78.9%), respiratory organs (64.3%), ears (57.8%), and skin (52.2%) in descending order. Statistically significant risk factors by multiple logistic regression analyses were sex, health examination, self assessed health status, and hand/finger posture in musculoskeletal symptoms; sex, self assessed health status, career, acid gas, and hand contact with resin mixture in deraml symptoms; Broka's smoking, exercise, self assessed health status, and face mask in respiratory symptoms; sex, hours of sleep, self assessed health status, work hours, work load, plaster dust, inadequate lighting, and goggle in eys symptoms, and eating, smoking, self assessed health status, and work load in ear symptoms. With the above considerations in mind, prevalence of subjective symptoms among Korean dental laboratory technicians was relatively high, and they were attributable to most of the occupational environment-related factors, work history, use of personal protective equipment, health habits and status, and general characteristics. Particularly, it is suggested that health promotion programs for promoting self- assessed health status and smoking cessation, preventive measures for protection of the female technicians’health, and reducing work load be necessary, since those factors were associated with more than one subjective symptom.

• Journal of Technologic Dentistry
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• v.28 no.1
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• pp.83-102
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• 2006

The purpose of this study is to understand the present conditions and problems of the joint education between industry and the academic world in the field of dental technology which were identified by the department of dental technology with the related industries and to meet their expectations for the cooperative education. The results of this study will be able to be furnished as basic data in deciding the direction of policy toward skillful dental technicians with a view to improving job employment rate of college graduates. The questionnaires for data were done by the dental technicians working in Daegu City and Kyeongbuk Province and students studying at the department of dental technology, Daegu Health College. The questionnaires of this study were processed by SPSS program. We could confirm through the investigation that on-the-job training as one of the joint policies between industry and the academic world is closely related to all the college education and that the results of on-the-job training can be expected under the close cooperation and the complementary relationship between industry and the academic world. Therefore, this study indicates the directions of policy toward skillful technicians through the cooperation between industry and the academic world as follows : 1. The cooperative systems among industry, academic world, and government are needed for the improvement of efficient job employment rate. The continuous training programs are needed to be built up for the maintenance and development of the technicians'specialty after employment. 2. The all-in-one educational programs both education and employment are needed for the on-the-job training through the cooperation between industry and the academic world, and the activation of the organizations which fully operate them is also needed. That's because the sufficient on-the-job training as one of the joint policies between industry and the academic world and the education of the whole man and the improvement of sociality for the expectant graduates in the academic world can be the methods which reduce the jobless rate and the job-change rate.

• 대한공업교육학회지
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• v.42 no.1
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• pp.68-86
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• 2017

The study aims to find the strategies to support the successful settlement of "Introduction to Intellectual Property" which was established as a new subject based on the 2015 Revised National Curriculum in order to assist high school students to explore career choices. For the research purpose accomplished, the study was performed to compare high school administrators' perception with teachers' regarding how they differently perceive the introduction and utilization of "Introduction to Intellectual Property" in the educational environment of high schools. The survey tool was developed through the content investigation of two experts in the field of invention education. Questionnaires were administered to 115 participants in a training course run by KIPA(Korea Invention Promotion Association) for high school administrators and teachers, which lasted for one month, December in the year of 2016. However, 95 questionnaires were analyzed for the research. SPSS 22.K was utilized for data analysis with the 5% significance level. The study findings are as follow: First, both administrators' group and teachers' showed the moderate level of perception according to the necessity of the subject as well as the curriculum content of "Introduction to Intellectual Property". Second, the two groups presented the above-average of preception according to the utilization of the subject, and the high level of perception regarding the necessity of strategies for the successful settlement in high schools. Third, teachers' perception on the curriculum of "Introduction to Intellectual Property" was higher than administrators' within the statistically significant level. Moreover, the two groups showed the significant difference only in the effort to facilitate intramural activities based on the subject regarding perceiving the necessity of the subject.

• Journal of Korean Society of Forest Science
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• v.101 no.4
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• pp.547-557
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• 2012

This study purposed to estimate the forest biomass using k-Nearest Neighbor (k-NN) algorithm. Multiple data sources were used for the analysis such as forest type map, field survey data and Landsat TM data. The accuracy of forest biomass was evaluated with the forest stratification, horizontal reference area (HRA) and spatial filtering. Forests were divided into 3 types such as conifers, broadleaved, and Korean pine (Pinus koriansis) forests. The applied radii of HRA were 4 km, 5 km and 10 km, respectively. The estimated biomass and mean bias for conifers forest was 222 t/ha and 1.8 t/ha when the value of k=8, the radius of HRA was 4 km, and $5{\times}5$ modal was filtered. The estimated forest biomass of Korean pine was 245 t/ha when the value of k=8, the radius of HRA was 4km. The estimated mean biomass and mean bias for broadleaved forests were 251 t/ha and -1.6 t/ha, respectively, when the value of k=6, the radius of HRA was 10 km. The estimated total forest biomass by k-NN method was 799,000t and 237 t/ha. The estimated mean biomass by ${\kappa}NN$method was about 1t/ha more than that of filed survey data.

• Journal of the Korean Geosynthetics Society
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• v.15 no.2
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• pp.55-64
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• 2016

The construction of the road NATM tunnel, which undergoes the weathered zone of the mountain, was in process with the reinforcement methods such as the rock bolt, shotcrete depositing, and the multi step grout with large diameter steel pipe. The collapse from the ceiling, and on the ground surface area(sink hole), of which were measured to be 25m from the ground surface($V=12m(W){\times}14m(L){\times}5m(H)=840m^3$), as well as excessive displacements in the tunnel, had occurred. In order to execute the necessary reconstruction work, the causes of the surface collapses were inspected through the field investigation, in-situ tests, and numerical analysis. As a result, several proper solutions were suggested for both internal and external reinforcements for the tunnel. As a result of numerical analysis, the collapsed zone of the tunnel was reinforced up to 0.5D~1.0D laterally by the cement grouting on the ground surface, 0.5D longitudinally by the multi step grout with large diameter steel pipe in tunnel. With further reinforcement implemented by rebars in lining, the forward horizontal boring was executed to the rest of the tunnel to evaluate the overall status of the tunnel face. Appropriate reinforcement methods were provided if needed.