• The Journal of Engineering Geology
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• v.23 no.1
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• pp.1-17
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• 2013

It is sometimes necessary to change the location of the collection conduit, which is constructed in shallow sediments in a stream, if the concentrations of $Fe^{2+}$ and $Mn^{2+}$ become too high for water treatment. A total of nine wells, including four shallow wells with a depth of 3 m and five deeper wells with a depth of 6 m, were installed in the study area at Naeseong-cheon in Yecheon-gun. The change in hydrogeochemical features of groundwater and the concentrations of $Fe^{2+}$ and $Mn^{2+}$ were examined at the wells during 5 hours of pumping. As pumping was performed, the velocity of groundwater flow was increased around the pumping well and aeration conditions were developed to precipitate iron and manganese oxides in an oxidizing environment. In addition, the concentrations of $Ca^{2+}$ and $Cl^-$ at the pumping well were increased following the mixing of surface water and groundwater. It is suggested that the center region of the stream would be more suitable for a new collection conduit, considering the concentrations of $Fe^{2+}$ and $Mn^{2+}$ in groundwater and their reducing effect during pumping. The installation of a collection conduit based on field tests performed to ensure water quality enables a reduction in the construction and management costs at water treatment facilities.

• Journal of Korean Academy of Nursing
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• v.25 no.2
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• pp.351-361
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• 1995

The main purpose of the study is to identify critical risk factors for development of a family assessment tool to screen high risk family. This study used a conceptual framework of family diagnosis developed by Eui-sook Kim's (1993) and analyzed risk factors to identify the high risk family. As employing a explorative and methodological study design, this study has four stages. 1. In the first stage, 34 family risk factors were identified by doing intensive literature review on conceptual framework of family diagnoses. 2. In the second stage, above risk factors were tested for content validity by consultation with 29 persons in community health nursing, nursing education, family theory, and social work. 3. In the third stage, existing survey data was used for actual application of the identified risk factors. The survey data used for this purpose was previously collected for the community diagnosis in a region of Seoul. At the final stage, through the comparison between high risk and low risk families, initially identified 34 risk factors decreased to 25 risk factors. Among 34 risk factors, six factors did not agree with content of questionnaries sand two factors were not significant in differentiating the high risk family Also, two risk factors showed high correlation between themselves, so only one of those two factors was chosen. As a result, twenty-five risk factors chosen to identify the high risk family are following ; 1. A single parent family due to divorce or death of a partner, or unweded single mother 2. A family with an unrelated household members 3. A family with a working mother with a young child 4. A family with no regular income 5. A family with no rule in family or too strict rules 6. A family with little or no support from other lam-ily members 7. A family with little or no support from friends or relatives 8. A family with little or no time to share with each other 9. A family with family history of hypertension, diabetus, cancer 10. A family with a sick person 11. A family with a mentally ill person 12. A family with a disabled person 13. A family with an alcoholic person 14. A family with a excessive smoker who smokes more than 1 pack / day 15. A family with too much salt intake in their diet. 16. A family with inappropriate management skills for family health 17. A family with high utilization of drug store than hospital to solve the health problems of the family 18. A family with disharmony between husband and wife 19. A family with conflicts among the family members 20. A family with unequal division of labor among family members 21. An authoritative family structure 22. A socially isolated family 23. The location of house is not residential area 24. A family with high risk of accidents 25. The drinking water and sewage systems are not hygienic. The main implication of the results of this study is clinical use. The high risk factors can be used to identify the high risk family effectively and efficiently. The use of high risk factors woule contribute to develop a conceptual framework of family diagnosis in Korea and the list of risk factors need to be revised continuously. Further researches are needed to develop an index of weight of each risk factor and to validate the risk factors.

• Korean Journal of Agricultural and Forest Meteorology
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• v.16 no.4
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• pp.403-417
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• 2014

Increased frequency of climate extremes is another face of climate change confronted by humans, resulting in catastrophic losses in agriculture. While climate extremes take place on many scales, impacts are experienced locally and mitigation tools are a function of local conditions. To address this, agrometeorological early warning systems must be place and location based, incorporating the climate, crop and land attributes at the appropriate scale. Existing services often lack site-specific information on adverse weather and countermeasures relevant to farming activities. Warnings on chronic long term effects of adverse weather or combined effects of two or more weather elements are seldom provided, either. This lecture discusses a field-specific early warning system implemented on a catchment scale agrometeorological service, by which volunteer farmers are provided with face-to-face disaster warnings along with relevant countermeasures. The products are based on core techniques such as scaling down of weather information to a field level and the crop specific risk assessment. Likelihood of a disaster is evaluated by the relative position of current risk on the standardized normal distribution from climatological normal year prepared for 840 catchments in South Korea. A validation study has begun with a 4-year plan for implementing an operational service in Seomjin River Basin, which accommodates over 60,000 farms and orchards. Diverse experiences obtained through this study will certainly be useful in planning and developing the nation-wide disaster early warning system for agricultural sector.

• Journal of Wetlands Research
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• v.18 no.4
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• pp.456-464
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• 2016

Korea established an inventory of 1,916 sites of inland wetlands during a nationwide investigation from 2000 to 2010. If inland wetlands is included in or near various protected areas designated by the government, it can be selected as a wetland to be managed with priority. This study evaluated the aspect of management of inland wetlands by analyzing the correlation between locations of national protected areas and inland wetlands. As a result, it was shown that a considerable percentage of current inland wetland was located in areas that were designated and managed as protected areas by the government, as they had a high value of natural environment protection (527 sites, 31.61 %). When the range was widened to a radius of 1 km for protected areas, 959 sites were included and 57.53 % of sites were located in or nearby the protected areas. Among them, 46.79 % of sites were distributed up to or within a 1 km radius of waterside areas and rivers; it accounted for 81.33 % of wetlands located in protected areas. Therefore, it was found that locations of current inland wetlands were mostly in contact with rivers. The results of overlay analysis were classified into high, medium and low; the correlation of location with inland wetlands was analyzed through the analysis of separation distance of various protected areas. The number of wetlands located in areas of a 'high' value of protection was 998 (59.87 %); 289 sites (17.34 %) were distributed in areas of a 'low' value of protection. This implies that these wetlands are located in artificial areas and are more exposed to environmental pressures. Thus, these wetlands could be determined as inland wetlands, which we considered for the establishment of measures to prevent damage.

• Journal of Korea Water Resources Association
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• v.48 no.7
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• pp.545-552
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• 2015

The objective of this study is to spatially assess the streamflow depletion due to groundwater pumping near the main stream of Juksanchoen watershed. The surface water and groundwater integrated model, SWAT-MODFLOW, in this study, was used to simulate streamflow responses to each groundwater pumping from wells located within 500m from the stream. The simulated results showed that the streamflow depletion rate divided by the pumping rate for each well location ranges from 20% to 96%. In particular, the streamflow depletion exceeds 60% of pumping rate if the distance between stream and well is lower than 100 m, hydraulic diffusivity is higher than $500m^2/d$, and streambed hydraulic conductance is above 25m/d. The simulated results were also presented in the form of spatial distribution maps that indicate the fraction of the well pumping rate in order to show the effect of a single well more comprehensively and easily. From the developed areal distribution of stream depletion, higher and more rapid responses to pumping occur near middle-downstream reach, and the spatially averaged percent depletion is about 66.7% for five years of pumping. The streamflow depletion map can provide objective information for the near-stream groundwater permission and management.

• Journal of the Korea Concrete Institute
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• v.22 no.3
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• pp.313-324
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• 2010

There are many problems in application of FRP reinforcing bars as shear reinforcement, since bending of FRP bars is not a feasible process on construction site. Even though FRP bars can be manufactured in bent shape, they have lower strength at bent location. However, there are no serious problems to use FRP bars as flexural reinforcement. Plates or slabs like bridge decks, in general, do not need shear reinforcements. These types of members with FRP flexural reinforcement have lower shear strength than those with conventional steel flexural reinforcement. However, reliable process or equation for shear strength estimation of FRP reinforced concrete without shear reinforcement are not established, yet. In this study, predicted shear strength obtained from available design equations and assessment equations are compared with 211 experimental results. The results showed that among the current design codes, the Architectural Institute of Japan (AIJ) and the Institution of Structural Engineers (ISE) provided the best estimation. ACI 440.1R-06 provided conservative results with degree of dispersion similar to that of ISE. In addition, regression analysis on the collected experimental results was conducted to develop regression models. As a result, a new reliable shear strength equation was proposed.

• The Korean Journal of Quaternary Research
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• v.18 no.2 s.23
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• pp.107-107
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• 2004

In this paper we have introduced some results of study on stand growth pattern and stand structure of larch forest which are located in selected forest sites of Khangai and Gobi-Altai mountain ranges of Mongolia. Our investigations showed that growth intensity and stand structure in western Mongolia are very specific from the other forest vegetation zones of Mongolia. Studies on the stand structure and growth trend indicate that tree types of stand structure and different types of growth of Larix sibrica are very common in Western Mongolia. These peculiarities of stand structure and growth of larch stands in Western Monolia could be used for inventory work and an improvement of the forest management in Western Mongolian region. The larch tree is the dominant tree species in Western Mogolia. Forest cover of the region is about 15%, which is two times higher than the country's average. In this region forest area is divided into 4 forest sub-regions: the Central Khangai, Western Khangai, North Eastern Khangai and South Easterun Khangai sub-regions including taiga, pseudo taiga, sub taiga, sub-alpine and forest steppe belts. Silviculture practices and forest research management request to study forest growth trends in local and general conditions, which means to indicate a change of taxonomic characteristics of stand from time to time including diameter, height, basal area, growth stock etc. The forest management practice mostly uses tables of forest growth and yield based on the results of long term research on forest growth. Forest yield tables and other relevant forest standards of Russia are used for the forest inventory and forest management. They are not able to determine forest structure and growth peculiatities of Mongolian forests. Studies on forest resource assessment in Mongolia indicate that after logging operations and forest fires the natural regeneration of desired species such as pine and larch often does not succeed. This situation forces to take a different approach of forest management and silviculture practice depending on the stand structure and growth rate of the forest stands. According to our investigation in last years, forest growth pattern of larch forest depends mostly on stand structure, stand age and growth condition including forest soil, climate and location in different slopes. Due to improve environmental function of forest ecosystem in the region, it is needed to conduct very comprehensive study of high mountain forest ecosystem in selected sub-regions.

• Journal of the Korean Association of Geographic Information Studies
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• v.19 no.3
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• pp.75-88
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• 2016

In this study, we used the CLUE-s model to predict the future land-use change based on the urban growth scenario in South Korea. The land-use maps of six classes (water, urban, rice paddy, upland crop, forest, and grass) for the year 2008 were obtained from the Ministry of Environment (MOE), and the land-use data for 5-year intervals between 1980 and 2010 were obtained from the Water Resources Management Information System (WAMIS), South Korea. For predicting the future land-use change, the MOE environmental conservation value assessment map (ECVAM) was considered for identifying the development-restricted areas, and various driving factors as location characteristics were prepared for the model. The predicted results were verified by comparing them with the land-use statistics of urban areas in each province for the year 2008. The prediction error rates were 9.47% in Gyeonggi, 9.96% in Gangwon, 10.63% in Chungbuk, 7.53% in Chungnam, 9.48% in Jeonbuk, 6.92% in Jeonnam, 2.50% in Gyeongbuk, and 8.09% in Gyeongnam. The sources of error might come from the gaps between the development of political decisions in reality with spatio-temporal variation and the mathematical model for urban growth rate in CLUE-s model for future scenarios. Based on the land-use scenario in 2008, the land-use predictions for the year 2100 showed that the urban area increased by 28.24%, and the rice paddy, upland crop, and forest areas decreased by 8.27, 6.72, and 1.66%, respectively, in South Korea.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.5
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• pp.402-407
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• 2010

Introduction: The planning of implant surgery is an important factor for the implant prosthesis. Stereolithographic (SLA) surgical stents based on a computer simulation are quite helpful for clinicians to perform the surgery as planned. Although many clinical and technical trials have been performed for computed tomography (CT)-guided implant stents to improve the surgical procedures and prosthetic treatment, there are still many problems to solve. We developed a system of a surgical guide based on 3 dimensional (3D) CT for implant therapy and achieved satisfactory results in the terms of planning and operation. Materials and Methods: Fifteen patients were selected and 30 implant fixtures were installed. The preoperative CT data for surgical planning were prepared after obtaining informed consent. Surgical planning was performed using the simulation program, Ondemend3D In2Guide. The stents were fabricated based on the simulation data containing information of the residual bone, the location of the nerve, and the expected design of the prostheses. After surgery with these customized stents, the accuracy and reproducibility of implant surgery were evaluated based on the computer simulation. The data of postoperative CT were used to confirm this system using the image fusion technique and compare the implant fixtures between the planned and implanted. Results: The mean error was 1.18 (${\pm}0.73$) mm at the occlusal center, 1.23 (${\pm}0.67$) mm at the apical center, and the axis error between the two fixtures was $3.25^{\circ}C$ (${\pm}3.00$). These stents showed superior accuracy in maxilla cases. The lateral side error at the apical center was significantly different from the error at the occlusal center but there were no significant differences between the premolars, 1st molars and 2nd molars. Conclusion: SLA surgical stents based on a computer simulation have the satisfactory accuracy and are expected to be useful for accurate planning and surgery if some errors can be improved.

• Journal of the korean academy of Pediatric Dentistry
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• v.42 no.1
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• pp.53-61
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• 2015

This study was conducted for the purpose of evaluating the stainless steel crowns on extracted primary molars and thus identifying frequent errors and defects. Visual assessment and micro-computed tomography (micro-CT) image analysis were performed on 97 primary molars for evaluation of the state of marginal adaptation, cement loss, secondary caries, ledge formation, attritive perforation and marginal polishing defect. The results were as follows: In the examination of object teeth by evaluation criteria, cement loss was found most frequently (98%), followed by secondary caries (42.3%), marginal polishing defect (41.2%), ledge formation (29.9%) and attritive perforation (17.5%), in this order. The cement loss at the margins showed a significant relationship with marginal gap and secondary caries: the larger the marginal gap is, the more frequent is the cement loss (p < 0.05). The average marginal gap was $0.31{\pm}0.26mm$ and showed the highest value in the maxillary 2nd primary molars. The location of the crown margin above the cementoenamel junction was found most frequently and it was found that the higher the crown margin is located, the less the marginal gap becomes (p < 0.05). In conclusion, it is thought very desirable to pay closer attention to crown margins and shapes for stainless steel crown restoration in order to minimize the marginal gaps and consequent cement loss.