• Journal of the Korean GEO-environmental Society
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• v.18 no.12
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• pp.37-45
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• 2017

Structural instability and damage are caused by frost heave during the winter when atmospheric temperature maintains below $0^{\circ}C$. Frost heave is the most representative engineering characteristics of frozen ground and there are various frost susceptibility criteria. Frost susceptibility criteria can be roughly divided into three categories. First, frost susceptibility is determined from particle size distribution, which is practically useful and many countries are adopting. In this paper, several particle size distributions (PSDs) are applied to the frost susceptibility criteria but PSD seems to be not enough to determine whether soils are frost susceptible. Second, it is judged from laboratory frost heave testing results. Laboratory frost heave tests were performed with newly developed thermal controlled triaxial cell and the reliability of frost susceptibility criteria is evaluated. New testing apparatus and method are suitable to meet the existing frost susceptibility criteria. Third, it is compositive frost susceptibility criteria envelope including the particle size distribution, soil classification, and frost heave test. The compositive frost susceptibility criteria envelope should be supplemented based on additional data on various soil types.

• The Korean Journal of Food And Nutrition
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• v.20 no.4
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• pp.487-493
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• 2007

Internet websites are excellent resources for younger people to gain information related to breastfeeding. So in this study, we evaluated the breastfeeding knowledge of university students, as well as the currently available website information on breastfeeding. Among the criteria, the six most important evaluation categories for the breastfeeding information on websites were selected and identified. The study participants completed the modified Williams and Hammer's tool, in order to evaluate their breastfeeding knowledge. An additional tool took into consideration the website breastfeeding information criteria, to evaluate the Korean websites. This 34 item tool was categorized into milk supply, comfort during breastfeeding, health of the baby and mother, social support, presentation of message, and products or financial motivation. Thirty-seven websites related to breastfeeding were evaluated, and the results were then discussed by nursing students. The students in this study were not knowledgeable on breastfeeding management with regard to the expression and storage of breast milk, the prevention and care of sore nipples, or use of breastfeeding aids. The breastfeeding information found on the Korean websites received positive evaluations for milk supply, comfort during breastfeeding, and health of the baby and mother. However, the educational content on social support, the message presentation, and the product areas on websites were rare or required additional information from breastfeeding specialists. In conclusion, based on our empirical survey, we need to design websites and evaluation tools for accurate website information regarding the social and economic benefits of breastfeeding, so that Korean women are better motivated to breastfeed by the information they obtain through the Internet.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.1
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• pp.91-102
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• 2014

Objectives: This study was performed in order to devise a procedure for supplementing the Special Management Materials in the Occupational Safety and Health Act and recommend candidate materials. The results are expected to be used as fundamental data for classification and criteria necessary to manage Special Management Materials in workplaces. Also, they are expected to be used as a basis for selecting target materials to nominate as additional Special Management Material. Methods: We investigated the selection standards for candidates and review ranges of data sources to nominate Special Management Materials. The substances classified as GHS(Globally Harmonized System of classification and labeling of chemicals) category 1A(known to have carcinogenic potential and reproductive toxicity for humans) or 1B(presumed to have carcinogenic potential and reproductive toxicity for humans) carcinogens and reproductive toxicants among the Controlled Hazardous Substances of the Regulation on Occupational Safety and Health Standards and substances with OELs(Occupational Exposure Limits) were inspected as the candidates for Special Management Materials. Conclusions: A seven-step procedure for selecting candidates to designate as Special Management Materials was suggested, including the setting of target chemicals for evaluation, classification of CMR(Carcinogens, Mutagens or Reproductive toxicants) by GHS classification and criteria, suggestion and selection of the candidates, and more. This study recommends 58 chemicals as qualified candidates to supplement the Special Management Materials.

• Design & Manufacturing
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• v.15 no.4
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• pp.24-31
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• 2021

In this study, an artificial neural network model was constructed to convert CAE analysis data into similar experimental data. In the analysis and experiment, the injection molding data for 50 conditions were acquired through the design of experiment and random selection method. The injection molding conditions and the weight, height, and diameter of the product derived from CAE results were used as the input parameters for learning of the convert model. Also the product qualities of experimental results were used as the output parameters for learning of the convert model. The accuracy of the convert model showed RMSE values of 0.06g, 0.03mm, and 0.03mm in weight, height, and diameter, respectively. As the next step, additional randomly selected conditions were created and CAE analysis was performed. Then, the additional CAE analysis data were converted to similar experimental data through the conversion model. An artificial neural network model was constructed to predict the quality of injection molded product by using converted similar experimental data and injection molding experiment data. The injection molding conditions were used as input parameters for learning of the predicted model and weight, height, and diameter of the product were used as output parameters for learning. As a result of evaluating the performance of the prediction model, the predicted weight, height, and diameter showed RMSE values of 0.11g, 0.03mm, and 0.05mm and in terms of quality criteria of the target product, all of them showed accurate results satisfying the criteria range.

• Journal of Trauma and Injury
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• v.35 no.3
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• pp.173-180
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• 2022

Purpose: The use of surgical stabilization of rib fractures (SSRF) has steadily increased over the past decade. Recent literature suggests that a larger population may benefit from SSRF, and that the geriatric population-as the highest-risk population-may receive the greatest improvement from these interventions. We sought to determine the overall utilization of SSRF in the United States. Methods: The National Trauma Database was analyzed between 2016 and 2017. The inclusion criteria were all patients ≥65 years old with rib fractures. We further stratified these patients according to age (65-79 vs. ≥80 years old), the presence of coding for flail chest, three or more rib fractures, and intervention (surgical vs. nonoperative management). The main outcomes were surgical interventions, mortality, pneumonia, length of stay, intensive care unit length of stay, ventilator use, and tracheostomy. Results: Overall, 93,638 patients were identified. SSRF was performed in 992 patients. Patients who underwent SSRF had improved mortality in the 65 to 79 age group, regardless of the number of ribs fractured. We identified 92,637 patients in the age group of 65 to 79 years old who did not undergo SSRF. This represents an additional 20,000 patients annually who may benefit from SSRF. Conclusions: By conservative standards and the well-established Eastern Association for the Surgery of Trauma clinical practice guidelines, SSRF is underutilized. Our data suggest that SSRF may be very beneficial for the geriatric population, specifically those aged 65 to 79 years with any rib fractures. We hypothesize that roughly 20,000 additional cases will meet the inclusion criteria for SSRF each year. It is therefore imperative that we train acute care surgeons in this skill set.

• Journal of Gastric Cancer
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• v.22 no.4
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• pp.339-347
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• 2022

Purpose: Lymphovascular invasion is a criterion for non-curative resection in patients who have undergone endoscopic submucosal dissection (ESD) for early gastric cancer (EGC). We aimed to determine the rate of extragastric metastasis (EGM) and identify the predictors of EGM in patients with negative resection margins (R0 resection) and lymphovascular invasion in post-ESD pathology. Materials and Methods: A total of 2,983 patients underwent ESD for EGC. Among them, 110 had a pathology of R0 resection and positive lymphovascular invasion. Patients underwent additional gastrectomy (n=63) or further follow-up without gastrectomy (n=47). Results: The 110 patients were assigned to one of the 3 groups according to ESD indications based on post-ESD pathology. The first group satisfied the absolute indication for ESD (n=18), the second group satisfied the expanded indications for ESD (n=34), and the last group satisfied the beyond indication (n=58). The number of occurrences of EGM in each group was 1 (5.6%), 3 (8.8%), and 3 (5.2%), respectively. The logistic regression analysis adjusted for age, sex, tumor size, and indication for ESD, showed that larger tumor size was associated with EGM (odds ratio, 1.76; 95% confidence interval, 1.00-3.10; P=0.048). In contrast, ESD indication criteria did not affect EGM (P=0.349). Conclusions: Tumor size was the only predictive indicator for EGM in patients who underwent R0 resection and lymphovascular invasion on post-ESD pathology. Even patients with pathology corresponding to the absolute indication criteria of ESD had lymphovascular invasion, which means that they require additional gastrectomy due to the risk of EGM.

• Journal of Korean Society of Disaster and Security
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• v.12 no.4
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• pp.1-13
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• 2019

Recently, as the occurrence frequency of sudden floods due to climate change increased, it is necessary to install the facilities that can cope with the initial stormwater. Most researches have been conducted on the design of facilities applying the Low Impact Development (LID) and the reduction effect on rainfall runoff to examine with 1D or 2D numerical models. However, the studies on the examination about flow characteristics and stability of pipe network systems were relatively insufficient in the literature. In this study, the stability of the pipe network system in rainwater storage tank was examined by using 3D numerical model, FLOW-3D. The changes of velocity and dynamic pressure were examined according to the number of rainwater storage tank and compared with the design criteria to derive the optimal design plan for a rainwater storage tank. As a results of numerical simulation with the design values in the previous study, it was confirmed that the velocity became increased as the number of rainwater storage tank increased. And magnitude of the velocity in pipes was formed within the design criteria. However, the velocity in the additional rainwater storage pipe was about 3.44 m/s exceeding the allowable range of the design criteria, when three or more additional rainwater storage tanks were installed. In the case of turbulence intensity and bottom shear stress, the bottom shear stress was larger than the critical shear stress as the additional rainwater storage was increased. So, the deposition of sediment was unlikely to occur, but it should be considered that the floc was formed by the reduction of the turbulence intensity. In addition, the dynamic pressure was also satisfied with the design criteria when the results were compared with the allowable internal pressure of the pipes generally used in the design of rainwater storage tank. Based on these results, it was suitable to install up to two additional rainwater storage tanks because the drainage becomes well when increasing of the number of storage tank and the velocity in the pipe becomes faster to be vulnerable to damage the pipe. However, this study has a assumption about the specifications of the rainwater storage tanks and the inflow of stormwater and has a limitation such that deriving the suitable rainwater storage tank design by simply adding the storage tank. Therefore, the various storage tank types and stormwater inflow scenarios will be asked to derive more efficient design plans in the future.

• Journal of Korean Society on Water Environment
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• v.28 no.4
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• pp.505-511
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• 2012

While the existing sewage treatment facilities are mainly being operated by biological processes, winter-time efficiency improvement and additional phosphorus treatment equipment using chemicals have been required to follow the effluent criteria of TP (0.2, 0.3 and 0.5 mg/L for the zone of I, II and III respectively) and $BOD_5$ (5.0 mg/L) which is intensified from 2012 in Republic of Korea. We made an investigation into actual condition of biological treatment process and calculated the optimal chemical input amount by jar test of supernatant of secondary sedimentation tank to evaluate the process improvement for the intensified criteria. Ejector BAF system for removing TP, $BOD_5$ of sewage effluent was suggested. The concentration of TP from biological process is 0.3-0.8 mg/L, and the input amount of optimal chemical coagulant was above Al/P ratio of 3(1.9 mg/L as Al) to meet the criteria of TP for secondary treatment effluent. From the results of this experiment, the best Al/P ratio for Ejector BAF system was about Al/P ratio of 1, and LV of BAF process for intensified criteria of $BOD_5$ and TP was below 1.97m/hr.

• YAKHAK HOEJI
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• v.56 no.2
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• pp.126-135
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• 2012

Purpose: To develop therapeutic duplication criteria for the drugs used for respiratory diseases. Method: Therapeutic duplication was defined as "more than 2 drug ingredient-usage in which each has the same therapeutic effect and combination therapy does not confer additional therapeutic benefit". Respiratory system drugs approved in Korea were examined for the study. The WHO's Anatomical Therapeutic Chemical Classification System was used for grouping of the corresponding drug ingredients. The principles and recommendations on combination usage or multiple drug regimens were reviewed by using the clinical practice guidelines, textbooks, product labelings, and clinical articles. Clinical expert group consultation was performed and expert opinions were incorporated into the final criteria. Results: Nine hundred sixty two drug products with Korean Food and Drug Administration classification codes of 141, 149, 222, and 229 were evaluated, of which 87 active ingredients were composed. The drug ingredients were classified into 12 groups (antihistamines, oral nasal decongestants, leukotriene receptor antagonists, inhaled anticholinergics, inhaled corticosteroids, oral ${\beta}2$-agonists, long-acting ${\beta}2$-agonists, short-acting ${\beta}2$-agonists, xanthines, antiallergics, mucolytics and cough suppressants). The use of more than 2 drug ingredients including the same group was therapeutic duplication, and thus combination should be recommended not to be used. Conclusion: Twelve drug groups were identified as therapeutic duplication criteria. Combination therapy within each group should not be used otherwise therapeutic benefits outweigh potential risks.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.3
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• pp.101-113
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• 2011

The purpose of this study are to develop a SDSS (Spatial Decision Support System) that can incorporate diverse opinions of stakeholders related the designation of protected areas (PA), and to employ the model for the readjustment of the boundary line of the Jirisan National Park of Korea. The SDSS would lead to more rational and less controversial decision-making during the expansion or removal of PA in Korea. Research methods are as follows. Firstly, to select evaluation criteria for SDSS for PA designation by using expert interview and literature survey. Secondly, to measure their preferences on the designation of additional PA or the removal of a part of PA based on the opinions of various stakeholders such as local residents, environmental groups, or public officials. Thirdly, to produce conservation priority maps based on a multi-criteria decision making technique. The SDSS would be used to rational decision making for the expansion of PA or the release of a certain part of PA by reflecting diverse preferences on biodiversity conservation and economic interest of residents. The visualization of conservation priority maps would also increase the efficiency of such decision making processes. The evaluation criteria for the expansion of PA for biodiversity conservation includes vegetation conservation value, wildlife conservation value, and the habitats of key species. The evaluation criteria for the removal of PA includes the proximity to roads and the boundary of PA, land use types, and conservation zoning of the PA. Preference weights are based on data collected from the Jirisan National Park. Both the conservation priority and removal priority maps are based on land parcels so that property rights of all parcels would be correctly represented.