• Membrane and Water Treatment
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• v.1 no.4
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• pp.283-296
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• 2010

During the disinfection of potable water, humic substances present in the solution react with chlorine to form potential carcinogenic compounds. This study evaluates the feasibility of using a submerged membrane photocatalysis reactor (SMPR) process for treatment of humic substances through the characterization of both organic removal efficiency and membrane hydraulic performance. A simple SMPR was operated and led to the removal of up to 83% of the polluting humic matters. Temporal rates of organic removal and membrane fouling were found to decrease with filtration time. Using tighter membrane in the hybrid process resulted in not only higher organic removal, but also more significant membrane fouling. Under the experimental conditions tested, optimum $TiO_2$ concentration for humic removal was found to be 0.6 g/L, and increasing initial pollutant concentration expectedly resulted in a more substantial membrane fouling. The importance of the influent nature and pollutant characteristics in this type of treatment was also assessed as various water sources were tested (model humic acid solution vs. local water containing natural organic matters). Results from this study revealed the promising nature of the SMPR process as an alternative technique for organic removal in the existing water treatment system.

• Journal of Veterinary Science
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• v.22 no.4
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• pp.48.1-48.15
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• 2021

Background: Porcine epidemic diarrhea virus (PEDV) is a swine enteropathogenic coronavirus that has devastated the swine industry in South Korea over the last 30 years. The lack of an effective method to control the endemics has led to a surge in PEDV recurrences in affected farms throughout the country. Objectives: In the first step toward establishing systematic monitoring of and active control measures over the swine populations, we constructed an assessment model that evaluates the status of (1) biosecurity, (2) herd immunity, and (3) virus circulation in each of the PEDV-infected farms. Methods: A total of 13 farrow-to-finish pig farms with a history of acute PEDV infection on Jeju Island were chosen for this study. The potential risk of the recurrence in these farms was estimated through on-site data collection and laboratory examination. Results: Overall, the data indicated that a considerable number of the PEDV-infected farms had lax biosecurity, achieved incomplete protective immunity in the sows despite multi-dose vaccination, and served as incubators of the circulating virus; thus, they face an increased risk of recurrent outbreaks. Intriguingly, our results suggest that after an outbreak, a farm requires proactive tasks, including reinforcing biosecurity, conducting serological and virus monitoring to check the sows' immunity and to identify the animals exposed to PEDV, and improving the vaccination scheme and disinfection practices if needed. Conclusions: The present study highlights the significance of coordinated PEDV management in infected farms to reduce the risk of recurrence and further contribute towards the national eradication of PEDV.

• The Journal of the Korea Contents Association
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• v.22 no.2
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• pp.58-70
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• 2022

The emergency preparedness exercise currently conducted by the government has been conducted as a message-based exercise for more than 50 years. Therefore, in this study, a simulation-based maintenance practice model was developed focusing on infectious disease situations, and the possibility of a training system applying scientific techniques was presented. As a result, First, a simulatioon logic assuming an infectious disease outbreak situation was developed. The situation of an infectious disease outbreak was made to occur when measures are not taken within 24 hours for the death due to disease, and when appropriate measures are not taken for contaminated food (24 hours), drinking water (12 hours), and drinking water shortage (24 hours). Second, in order to implement the simulation logic, simulation engine SW was developed for emergency medical team, epidemiological investigation team, dead burial team, quarantine and disinfection team, etc., and situation map SW was developed so that these contents could be expressed in the situation map. As suggested in this paper, if scientific techniques are applied to the simulation-based government practice model to expand the scope, training will be possible by creating practical situations that can occur in the real world, and the Chungmu plan and various emergency preparedness plans will be verified.

• Korean journal of food and cookery science
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• v.19 no.4
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• pp.477-492
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• 2003

The purposes of the study were to establish HACCP-based standards and guidelines for conducting a plan review to build, or renovate, hospital food service establishments, and ensure the safety of foodservice and reduce the risk of food borne illness. The scope of the study included suggestion for the planning of hospital foodservice facilities: layout, design, equipment and modeling. The results of this study can be summarized as follows: 1) The development of a foodservice facility plan based on the results of a survey, literature reviews and the results of interviews with foodservice managers from 9 general hospitals. This was composed of operational policies in foodservices, layout characteristics, space allocation, selection, design, specification standards for equipment and the construction principles of foodservice facilities. 2) Two foodservice facility models were developed, one for general hospitals with 900 beds (2,000 patients and 2,500 employee meals per day) and the other for general hospitals with 300 beds (600 patients and 650 employees meals per day). 3) The suggested kitchen space requirements for the foodservice facility models were 341.2 ㎡ (W 17,100mm x L 23,700mm) and 998.8㎡ (W 35,600mm x L 32,800mm) for the 300 and 900 beds hospitals, respectively, with both designs being rectangular. The space requirements for the equipment, in relation to the total operational area, in terms of ratios were 1:3.5 and 1:3.8 for the 300 and 900 beds hospitals, respectively. The recommended space allowances per bed for the developed foodservice facility models were 1.15 ㎡ and 1.11 ㎡ for the 300 and 900 beds hospitals, respectively, which were increased by more than 30% compared to those suggested in the precedent study, and considered appropriate for the implementation of the HACCP system. 4) The hospital foodservice facilities plans and models were developed based on the general sanitation standards, guidelines and the HACCP system, and included foodservice facility layout, product flow, physical separation between contaminated and sanitary areas, foodservice facility specifications with a 1/300 scale for a 300 bed, and a 1/400 scale for a 900 beds blueprint. 5) The main features of the developed foodservice facility plans and models were; physical separation between contaminated and sanitary areas to prevent cross contamination, product flow in one direction from the arrival of the raw material to the finished product, and separation of different work areas and the process of receiving & preparation of products, refrigeration & storage, cooking, assembly, cleaning & disinfection, employee areas and janitorial facilities. The proposed models from this study were presented as examples for those wanting to build, or renovate, their facility for the production of foods.

• Journal of Korea Water Resources Association
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• v.57 no.3
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• pp.151-164
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• 2024

In water treatment plants supplying potable water, the management of chlorine concentration in water treatment processes involving pre-chlorination or intermediate chlorination requires process control. To address this, research has been conducted on water quality prediction techniques utilizing AI technology. This study developed an AI-based predictive model for automating the process control of chlorine disinfection, targeting the prediction of residual chlorine concentration downstream of sedimentation basins in water treatment processes. The AI-based model, which learns from past water quality observation data to predict future water quality, offers a simpler and more efficient approach compared to complex physicochemical and biological water quality models. The model was tested by predicting the residual chlorine concentration downstream of the sedimentation basins at Plant, using multiple regression models and AI-based models like Random Forest and LSTM, and the results were compared. For optimal prediction of residual chlorine concentration, the input-output structure of the AI model included the residual chlorine concentration upstream of the sedimentation basin, turbidity, pH, water temperature, electrical conductivity, inflow of raw water, alkalinity, NH₃, etc. as independent variables, and the desired residual chlorine concentration of the effluent from the sedimentation basin as the dependent variable. The independent variables were selected from observable data at the water treatment plant, which are influential on the residual chlorine concentration downstream of the sedimentation basin. The analysis showed that, for Plant, the model based on Random Forest had the lowest error compared to multiple regression models, neural network models, model trees, and other Random Forest models. The optimal predicted residual chlorine concentration downstream of the sedimentation basin presented in this study is expected to enable real-time control of chlorine dosing in previous treatment stages, thereby enhancing water treatment efficiency and reducing chemical costs.

• Journal of the Korean Dietetic Association
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• v.4 no.2
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• pp.235-244
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• 1998

Hand washing is an important component of hygiene program for food handlers. Hands can be a source of direct or indirect contamination of foods with pathogenic microorganisms. In this study, the effectiveness of hand washing methods and the use of 70% alcohol solution against transient skin bacteria was tested in an university foodservice facility. 70% alcohol solution is sprayed for 5 seconds automatically when hands are placed in the dispenser. Samples were taken using swab technique in meat cutting area, vegetable trimming area, and vegetable cutting area: before and after washing hands according to planned methods, and after being sprayed with 70% alcohol solution after washing hands. The bacteriological analysis of total plate counts, coliform, fecal coliform of food handlers' hands was done. Statistical data analysis was completed with Mann-Whitney U test and Kruskal-Wallis model using the SPSS program. The levels of initial contamination of workers' hand were significantly different by the work areas($x^2$=9.156, p<0.01). Workers in the vegetable trimming area had more heavily soiled hands than in the other work areas. Mean of TPC counts and coliform was 8.97×$10^5$ CFU/12.4$cm^2$, 2.93×$10^2$ MPN/12.4$cm^2$ respectively, but fecal coliform was not detected. Transient bacteria were removed from hands after washing and using 70% alcohol solution but were not removed completely. Mean reduction percentage in TPC varied among work areas and ranged from 93.19% to 94.99%, and in coliforms from 97.31% to 100%. A significant difference in TPC was found between before and after hand disinfection (Z=-2.714, p<.01) and between standardized hand washing procedures and un-standardized hand washing procedures(z=-2.301, p<.01). Subjects using the hand sanitizer showed a great elimination of TPC(99.45% reduction), but this effect was valid only after following proper washing procedures. Based on the results, the most effective hand washing method was recommended as the combination of the standardized hand washing procedure with warm-water and use of the 70% alcohol solution. The results can be used to develop hand hygiene programs and training strategies for enhancing hand hygiene practices for food handlers in foodservice operations.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.12 no.3
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• pp.104-113
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• 1998

In genral, the water process facilities include the purification plant, the waste water plant and the process of this purification plant is consisted of the intake, coagulation, settling, filtration, disinfection. The coagulation is very important in filtration processing plant and is very related to process of turbidity. The coagulation to the turbidity is, however, not yet to be clarified and the amount of coagulant can not be easily calculated. Moreover the coagulant dosing amount has to be decided adaptively according to the qualities of the raw water. So, the automation of chemicals dosing process and the supervisory system were needed to improve the performance of facilities. In this paper, a neural network is employed to model the coagulation to the turbidity of the treated water and the historical jar-test data are used to train the neural network. And also, an automation system to support the coagulant dosing process using the neural network was implemented and was shown by the field test. This automation system for the operator support system was constructed the environment to supervise the state an management of facilities for the maintenance.

• Journal of Korean Academy of Nursing
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• v.29 no.6
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• pp.1455-1468
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• 1999

The purpose of this study was to investigate the objectives and contents of basic medical sciences at department of nursing in college of nursing, and junior college of nursing, thus ultimately providing the basic data to standardize the curriculum of the basic medical sciences in nursing education. Seventy eight professors who were in charge of teaching basic medical sciences to at 22 colleges of nursing/ department of nursing, and 20 junior colleges of nursing responded to the questionnaires that consisted of the questions regarding objectives and contents, of basic medical sciences. Based on the description of objectives, the description related to nursing, nurse, nursing science was cathegorized as on objective applicable to nursing science, the description related to medicine or clinical medicine as medical model, the description without description related to medicine was cathegorized as knowledge acquisition. The number of schools corresponding to each category were summerized in descending order. The objectives of basic medical sciences were categorized by concepts and number of schools corresponding to the categorized concept. The findings of the study are as follows ; 1. The subjects of basic medical science identified were physiology, anatomy, biochemistry, pathology, microbiology, and pharmacology in most colleges of nursing and junior colleges. Two colleges of nursing/department of nursing (9.1%) and 19 junior colleges of nursing(95%) did not offer biochemistry, 1 college of nursing /department of nursing(5%) did not offer pathology & pharmacology. 2 junior colleges of nursing (10%) did not offer pharmacology, 1 junior college of nursing(5%) did not offer pathology. The other 1 junior college of nursing did not offer microbiology. 2. Objectives of physiology were to acquire knowledge and understanding on human function in both 6 (50%) colleges and 5 junior colleges. Objectives of anatomy were to acquire knowledge on human structure in both 4 (57%) colleges and 2 (50%) junior colleges; knowledge applicable to nursing sciences in both 3 (42.8%) colleges and 2 (50%) junior colleges. Objectives of biochemistry was to obtain knowledge and understanding on biochemistry, and understanding of basic concepts about biochemistry. Objectives of pathology were to obtain knowledge and understanding on pathology in both 4 (57.1%) colleges and 5(62.5%) junior colleges. Objectives of microbiology were to acquire knowledge and understanding on microbiology in both 5(83.8%) colleges and 6(85.7%) junior colleges. Objectives of pharmacology were to acquire knowledge on pharmacology in both 7(100%) colleges and 8(100%) junior colleges. 3. Contents of physiology in 19 (100%) schools were membrane transport, digestion, circulation, nervous system and respiration. In 16(84.2%) were kidney and muscle, that in 13(68.4%) were endocrine physiology. In 11(57.9%) were introduction and that in 9(47.4%) were structure and function of cells. Contents of anatomy in 11(100%) schools were skeletal system, muscle system, digestive system, circulatory system, concepts regarding human structure. In 10(90.9%) schools were endocrine system and nervous system, and in 5(45.5%) schools were blood, urinary system and cell. Contents of biochemistry in 6(100%) schools were history of biochemistry, body regulating factor, bioenergy, health and nutrition, nutrition of cell, energy production system. In 5(83.3%) schools were metabolism of protein and carbohydrate and enzyme, and in 3(50%) schools were metabolism of energy and fat. Contents of microbiology in 13(100%) schools were environment and influenc of bacteria, virus, G(-) rods, purulent cocci, G(+) rods. In 10 (76.9%) were immunity, diphtheria, enterobacteria, and in 9(69.2%) were spirochete, rickettsia and clamydia, and that in 6(46.2%) were sterilization and disinfection. Contents of pathology in 14(100%) schools were cell injury and adaptation, inflammation, respiratory diseases, circulatory diseases. In 10(71.4%) were neurological disorders, in 8(57.1%) were immunity and disease, and in 7 (50%) were tumor and progressive changes. Contents of pharmacology in 15(100%) were cardivascular drugs, introduction to pharmacology, hypnotics, analgesics, local anesthetics, an ticonvulsants. In 12(80%) were drugs activity on sympathetic and parasympathetic nervous system, and in 11(73%) were sulfa drugs, antibiotics, drug abuse and addiction.

• Korean Journal of Ecology and Environment
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• v.38 no.2 s.112
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• pp.225-236
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• 2005

The protection of public health In wastewater reclamation and reuse is one of the most important issues. Monitoring data of Escherichia coli were collected from paddy rice plots in 2003 and 2004 experiments. Five treatments were used and each one was triplicated to evaluate the changes of E. coli: surface water, biofilter effluent (secondary level), UV-disinfected water and pond treatment. Microbial risk was quantified to assess human health risk by exposure to E. coli in paddy rice plots, which were irrigated with reclaimed wastewater. Beta-Poisson model was used to estimate the microbial risk of pathogen ingestion that may occur to farmer and neighbor children. Monte-Carlo analysis (10,000 trials) was used to estimate the risk characterization of uncertainty. In the following analysis, two scenarios were related to the reduction of risk against direct ingestion and exposure times. Scenarios A and B were assumed that the risk was 1,000 and 10,000 times lower than direct ingestion.'Golfers were assumed to be 0.001 L of reclaimed water by contact with balls and their cloths. Opportunity of contact in paddy rice field with pathogens was more frequent than handing golf balls, because of agricultural activity was practiced in ponded water in paddy rice culture. As a result of microbial risk assessment using total data of experimental period, risk value of E. coli in 2003 and 2004 experiment ranged from $10^{-5}$ to $10^{-8}$ and $10^{-4}$ to $10^{-8}$, respectively. The risk values in biofilter effluent irrigation was the highest, which is $10^{-4}$ in 2003 and $10^{-5}$ in 2004 experiments with scenario A. Ranges of $10^{-6}$ to $10^{-8}$ were considered at reasonable levels of risk for communicable disease transmission from environmental exposure and the risk value above $10^{-4}$ was considered to be attributable to the risk of infection. Irrigation with UV-disinfected water in the paddy field during the agricultural Period showed significantly lower microbial risk than others, and their levels of risk value were within the range of actual paddy rice field with surface water.