• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.6
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• pp.346-361
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• 2013

This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2012. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. The conclusions are as follows : (1) The research works on thermal and fluid engineering have been reviewed as groups of fluid machinery, pipes and valves, fuel cells and power plants, ground-coupled heat pumps, and general heat and mass transfer systems. Research issues are mainly focused on new and renewable energy systems, such as fuel cells, ocean thermal energy conversion power plants, and ground-coupled heat pump systems. (2) Research works on the heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer, and industrial heat exchangers. Researches on heat transfer characteristics included the results for natural convection in a square enclosure with two hot circular cylinders, non-uniform grooved tube considering tube expansion, single-tube annular baffle system, broadcasting LED light with ion wind generator, mechanical property and microstructure of SA213 P92 boiler pipe steel, and flat plate using multiple tripping wires. In the area of pool boiling and condensing heat transfer, researches on the design of a micro-channel heat exchanger for a heat pump, numerical simulation of a heat pump evaporator considering the pressure drop in the distributor and capillary tubes, critical heat flux on a thermoexcel-E enhanced surface, and the performance of a fin-and-tube condenser with non-uniform air distribution and different tube types were actively carried out. In the area of industrial heat exchangers, researches on a plate heat exchanger type dehumidifier, fin-tube heat exchanger, an electric circuit transient analogy model in a vertical closed loop ground heat exchanger, heat transfer characteristics of a double skin window for plant factory, a regenerative heat exchanger depending on its porous structure, and various types of plate heat exchangers were performed. (3) In the field of refrigeration, various studies were executed to improve refrigeration system performance, and to evaluate the applicability of alternative refrigerants and new components. Various topics were presented in the area of refrigeration cycle. Research issues mainly focused on the enhancement of the system performance. In the alternative refrigerant area, studies on CO2, R32/R152a mixture, and R1234yf were performed. Studies on the design and performance analysis of various compressors and evaporator were executed. (4) In building mechanical system research fields, twenty-nine studies were conducted to achieve effective design of mechanical systems, and also to maximize the energy efficiency of buildings. The topics of the studies included heating and cooling, HVAC system, ventilation, renewable energy systems, and lighting systems in buildings. New designs and performance tests using numerical methods and experiments provide useful information and key data, which can improve the energy efficiency of buildings. (5) In the fields of the architectural environment, studies for various purposes, such as indoor environment, building energy, and renewable energy were performed. In particular, building energy-related researches and renewable energy systems have been mainly studied, reflecting interests in global climate change, and efforts to reduce building energy consumption by government and architectural specialists. In addition, many researches have been conducted regarding indoor environments.

• Korean Journal of Organic Agriculture
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• v.24 no.4
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• pp.833-847
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• 2016

Drought stress is a major agricultural limitation to crop productivity worldwide, especially by which leafy vegetables, plant leaves eaten as vegetable, could be more lethal. The study was carried out to know the effect of drought tolerance plant growth promoting bacteria (PGPB) on water stress of kale seedlings. A total of 146 morphologically distinct bacterial colonies were isolated from bulk soil and rhizosphere soil of leafy vegetables and screened for plant growth promoting microbioassay in greenhouse. Out of them the isolate SB19 significantly promoted the growth of kale seedlings in increasement of about 42% of plant height (14.1 cm), 148% of leaf area ($19.0cm^2$) and 138% of shoot fresh weight (1662.5 mg) attained by the bacterially treated plants compared to distilled water treated control (9.9 cm, $7.7cm^2$, 698.8 mg). Shoot water content of SB19 treated kale seedlings (1393.8 mg) was also increased about 152% compared with control (552.5 mg). The SB19 isolated from bulk soil of kale plant in Iksan, Korea, was identified as species of Bacillus based on 16S rRNA gene sequencing analysis. We evaluated the effect of drought tolerance by the Bacillus sp. SB19 on kale seedlings at 7th and 14th days following the onset of the water stress and watering was only at 7th day in the middle of test. In the survey of 7th and 14th day, there were mitigation effect of drought stress in kale seedlings treated with $10^6$ and $10^7cell\;mL^{-1}$ of SB19 compared to distilled water treated control. Especially, there were more effective mitigation of drought damage in kale seedlings treated with $10^7cell\;mL^{-1}$ than $10^6cell\;mL^{-1}$. Further, although drought injury of bacterially treated kale seedlings were not improved at 14th day compared with 7th day, drought injury of $10^7cell\;mL^{-1}$ of SB19 treated kale seedlings were not happen rapidly but developed over a longer period of time than $10^6cell\;mL^{-1}$ of SB19 or control. The diffidence of results might be caused by the concentration of bacterial suspension. This study suggests that beneficial plant-microbe interaction could be a important role of enhancement of water availability and also provide a good method for improving quality of leafy vegetables under water stress conditions.

• Journal of Bio-Environment Control
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• v.27 no.1
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• pp.94-101
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• 2018

Mugwort (Artemisia princeps) is a medicinal plant that has a substance called euphatilin, which is effective for cell damage and gastritis recovery. The objectives of this study were to investigate the annual growth characteristics of Artemisia princeps in greenhouse and to increase the eupatiline content by environmental stresses. Growth and eupatilin content of the plants were compared after 6 weeks of seedling and subsequent 8 weeks of greenhouse cultivation. Photosynthesis of mugwort plants did not saturate even at a relatively high light intensity of $1,200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. Growth rate of the plants reached its highest at two weeks after transplanting and began to decrease since 8 weeks after transplanting. The plants showed typical characteristics of a perennial herbaceous plant as they were sensitive to seasonal changes. In particular, the plants showed high growth and eupatilin content in spring and summer as vegetative growth periods, but flowering and wintering caused considerable decreases in growth and eupatilin content in fall and winter. Therefore, application of night interruption is essential for year-round cultivationof the plant. Two stresses and a elicitor were treated: drought stresses by stopping irrigation at 5, 6, 7, and 8 days before harvest; salt stresses with nutrient solution concentrations of 2, 4, 6, 8, and $10dS{\cdot}m^{-1}$ by adding sodium chloride at 3 days before harvest; and foliar applications of methyl jasmonates of 12.5, 25, 50, and $100{\mu}M$ at 3 days before harvest. Significant increase in eupatilin content was observed at drought stresses of 7- and 8-days of irrigation stop and foliar application of $25{\mu}M$ methyl jasmonate, while no significant increase observed at salt stresses. From the results, it was confirmed that the environmental treatments can improve the productivity and quality of Artemisia princeps as a phamaceutical raw material.

• Journal of Environmental Impact Assessment
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• v.30 no.5
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• pp.271-296
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• 2021

Since the thermal stratification in a reservoir inhibits the vertical mixing of the upper and lower layers and causes the formation of a hypoxia layer and the enhancement of nutrients release from the sediment, changes in the stratification structure of the reservoir according to future climate change are very important in terms of water quality and aquatic ecology management. This study was aimed to develop a data-driven inflow water temperature prediction model for Daecheong Reservoir (DR), and to predict future inflow water temperature and the stratification structure of DR considering future climate scenarios of Representative Concentration Pathways (RCP). The random forest (RF)regression model (NSE 0.97, RMSE 1.86℃, MAPE 9.45%) developed to predict the inflow temperature of DR adequately reproduced the statistics and variability of the observed water temperature. Future meteorological data for each RCP scenario predicted by the regional climate model (HadGEM3-RA) was input into RF model to predict the inflow water temperature, and a three-dimensional hydrodynamic model (AEM3D) was used to predict the change in the future (2018~2037, 2038~2057, 2058~2077, 2078~2097) stratification structure of DR due to climate change. As a result, the rates of increase in air temperature and inflow water temperature was 0.14~0.48℃/10year and 0.21~0.41℃/10year,respectively. As a result of seasonal analysis, in all scenarios except spring and winter in the RCP 2.6, the increase in inflow water temperature was statistically significant, and the increase rate was higher as the carbon reduction effort was weaker. The increase rate of the surface water temperature of the reservoir was in the range of 0.04~0.38℃/10year, and the stratification period was gradually increased in all scenarios. In particular, when the RCP 8.5 scenario is applied, the number of stratification days is expected to increase by about 24 days. These results were consistent with the results of previous studies that climate change strengthens the stratification intensity of lakes and reservoirs and prolonged the stratification period, and suggested that prolonged water temperature stratification could cause changes in the aquatic ecosystem, such as spatial expansion of the low-oxygen layer, an increase in sediment nutrient release, and changed in the dominant species of algae in the water body.

• Journal of Dental Rehabilitation and Applied Science
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• v.27 no.1
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• pp.25-39
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• 2011

In animal studies, Magnesium (Mg) - incorporated oxidized implants showed significant enhancement of the bone response. This prospective clinical trial was performed to investigate the success rate, implant stability and marginal bone loss of Mg oxidized clinical implant. The experimental protocol was approved by Institutional Review Board of the Gangneung-Wonju National University Dental Hospital. Fifty healthy patients had partial edentulism were included in this study. Mg oxidized clinical implants (Implant M, Shinhung, Korea) were installed and restored with conventional protocol. The patients were recalled at 1, 3, 6 months after functional loading. Implant stability quotient (ISQ) was measured and periapical radiographic images were obtained. Amount of marginal bone loss was calculated with calibrated images from periapical radiographs. Repeated measured analysis of variance and post hoc Tukey test were used to compare the mean ISQ and bone level. A total of 101 implants were analyzed. The mean ISQ values increased continuously with time lapse from 68.4 at fixture installation to 71.5 at 6 months after loading. Implant stability was correlated with gender, fixture diameter, bone quality and implant sites. The mean marginal bone loss during 6 months after loading was 0.26 mm. There was no failed implant and six-month success rate was 100%. Within the limitations of this study, the six-month success rate of Mg oxidized implant was satisfactory. The implant stability and marginal bone level were excellent. However, further longer clinical studies will be needed to confirm the success of Mg oxidized clinical implant.

• 한국노년학
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• v.31 no.4
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• pp.1155-1167
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• 2011

The purpose of this study was to investigate the frequency of falls, fear of falling, perceived health status, and number of disease according to cognitive function in community-dwelling the elderly women. This study utilized a descriptive survey design. Data were collected for six months with 311 elderly women who visited in public health center at S city. After obtaining Institutional Review Board(IRB) approval, a face-to-face, and private interview was conducted with each participant who was eligible and agreed to participate in this study by trained graduate-level nursing students. The questionnaires consisted of MoCA-K, K-MMSE, Fall Efficacy Scale, PHS scale. The collected data were analyzed with SPSS/WIN 17.0 program, which was used descriptive statistics, Chi-Square test and t-test, Correlation. The major findings of this study were as follows; 1) The average age of the subjects was 71.68±5.13 and cognitive function score was 22.14±4.32. approximately 35% of participants had fallen within one year. 2) there were significant differences in perceived health status according to cognitive function. 3) fear of fall and cognitive function, perceived health status and cognitive function were significant correlation. In conclusion, this study will contribute to establish strategies for preventing fall. Interventions for fall prevention and fear of fall enhancement should be developed with the consideration of the level of cognitive function in the elderly. Reducing the fear of falling through the comprehensive nursing intervention will ultimately improve the quality of life in the elderly.

• Journal of the Korean Society of Radiology
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• v.10 no.1
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• pp.29-37
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• 2016

This study aims to improve the satisfaction level of the patient who undergoes CT contrast examination by developing and applying pretreatment process system, which not only can reduce the side effects caused by the test but also can help carry out the test smoothly. The subjects were 214 patients who booked CT contrast examination from January 2014 to February 2014 but could not carry out their test on schedule. We analyzed the reasons for the delay and conducted follow-up survey on them. We analyzed the usefulness of pretreatment process system by contemplating and developing pretreatment process system and applying it to the patients for whom follow-up survey was conducted from January 2015 to February 2015. The number of outpatients who came to the hospital form January to February 2014 was 2,846 and the number of patients who could not undergo the test was 214, accounting for 7.52% of the total. The specific reason for the delay includes 214 cases of unknown creatinine 98 with 120 minutes of average delay time, 40 cases of creatinine over 1.3(19%) with 30minutes of average delay time, 34 cases of past contrast media side effect 6% with 40 minutes of average delay time and 25 cases of lack of pretreatment such as fasting, etc. 11% with 120minutes of average delay time. The number of CT scan has been increasing ever since the development of CT and the frequency of using the contrast media is expected to increase. If we can employ pretreatment process system in order to effectively control the side effect of contrast media and help the CT contrast examination to be smoothly conducted on schedule, I'm sure we could improve the quality of our medical service and increase our patients' satisfaction who come to our CT scan room.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.6
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• pp.427-446
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• 2008

A review on the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2006 has been accomplished. Focus has been put on current status of research in the aspect of heating, cooling, ventilation, sanitation and building environments. The conclusions are as follows. (1) The research trends of fluid engineering have been surveyed as groups of general fluid flow, fluid machinery and piping, etc. New research topics include micro heat exchanger and siphon cooling device using nano-fluid. Traditional CFD and flow visualization methods were still popular and widely used in research and development. Studies about diffusers and compressors were performed in fluid machinery. Characteristics of flow and heat transfer and piping optimization were studied in piping systems. (2) The papers on heat transfer have been categorized into heat transfer characteristics, heat exchangers, heat pipes, and two-phase heat transfer. The topics on heat transfer characteristics in general include thermal transport in a cryo-chamber, a LCD panel, a dryer, and heat generating electronics. Heat exchangers investigated include pin-tube type, plate type, ventilation air-to-air type, and heat transfer enhancing tubes. The research on a reversible loop heat pipe, the influence of NCG charging mass on heat transport capacity, and the chilling start-up characteristics in a heat pipe were reported. In two-phase heat transfer area, the studies on frost growth, ice slurry formation and liquid spray cooling were presented. The studies on the boiling of R-290 and the application of carbon nanotubes to enhance boiling were noticeable in this research area. (3) Many studies on refrigeration and air conditioning systems were presented on the practical issues of the performance and reliability enhancement. The air conditioning system with multi indoor units caught attention in several research works. The issues on the refrigerant charge and the control algorithm were treated. The systems with alternative refrigerants were also studied. Carbon dioxide, hydrocarbons and their mixtures were considered and the heat transfer correlations were proposed. (4) Due to high oil prices, energy consumption have been attentioned in mechanical building systems. Research works have been reviewed in this field by grouping into the research on heat and cold sources, air conditioning and cleaning research, ventilation and fire research including tunnel ventilation, and piping system research. The papers involve the promotion of efficient or effective use of energy, which helps to save energy and results in reduced environmental pollution and operating cost. (5) Studies on indoor air quality took a great portion in the field of building environments. Various other subjects such as indoor thermal comfort were also investigated through computer simulation, case study, and field experiment. Studies on energy include not only optimization study and economic analysis of building equipments but also usability of renewable energy in geothermal and solar systems.

• Journal of the Korean Society for Library and Information Science
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• v.30 no.1
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• pp.89-123
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• 1996

The world has moved from the Cold War between the east and the west and moved toward the age without idealogy. It places emphasis on economic benefit and welfare of its own nation as its main point With this world trend, in order to sam the competitiveness and the reconciliation of the divided nation the north and the south Korea should be united. Once the north and the south are united, information society will be altered with the huge flow of the civilization. At the same time, the issue of how to operate library policies and system, in which effective acquisition, manipulation, accumulation, and dissemination of information un would be very important. From this point of view, the following conclusions are obtained in this study. Firstly, when building a national library preparing for the national unification. it is essential to introduce 1) the concept of policy and system for information society and 2) that of policy and system which has national-culture as its focus. Secondly, it is essential to prepare the cooperative-structure between libraries prior to the national unification. This kind of cooperation should gradually expand to an extent that allows actual benefits such as building union catalog, inter-library loan system, resource sharing, standardized cataloging rules, and exchange of dissertation... etc. Thirdly, developing the library policies and systems for the national unification must be based on the concept of the mutual cooperation as inter-dependent model rather than on the concept of the incorporation-absorption as a dominant model. The next point the principles of the followings in preparing the library policies should be considered: 1) free-competition, 2) revolution of consciousness through the social education, 3) independence and love for humanity, 4) scientific or reasonable thinking, 5) job responsibility, 6) democratic citizenship, 7) mind far collective life, 8) spirit of public interest 9) globalization In addition, the model of the library systems preparing for thenational unification should include the followings : 1) uniformity of library system and its authority, 2) establishment of research institutes for library policy and system, 3) exchange of library establishment and information resources, 4) building library networks, 5) establishment of education systems for the library and information science and enhancement of its quality, 6) modernizing and developing information technology and its transfer. Finally, the libraries in the north and the south has different concepts, goals, information resources, and the different ways of using them. Considering the practical aspects of the libraries and the reasons for their existence, they must structure the mutual cooperative system so as to minimize the shock when confronting the social changes, so-called the national unification.

• Journal of radiological science and technology
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• v.26 no.3
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• pp.33-39
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• 2003

Purpose : Be aware of clinical possibilities on image quality by comparison of contrast-enhanced dynamic CT and MR imaging applied of MIP technique after the experimentally induced clonorchasis infection in dogs. Materials and Method : Twenty mongrel dogs prepared in zoo-laboratory were followed up with serial CT scans and MR imaging for 13 weeks after the experimental infection in liver. Two-phase helical CT was acquired in the supine position with the following scanning parameters. After the injection of contrast material, the arterial phase was initiated using a bolus-racking method. The portal phase scan was started 15 seconds after the arterial phase scan. CT protocol was determined after single level dynamic scans. MR imaging used the CP body coil and images get a 2D image using HASTE, FLASH, TSE pulse sequence. Bile duct MR imaging were obtained in three plans. Then each image was post processed by using target MIP algorithm. Two experimentation above, as a method of evaluation, one pathologist, three radiologist and five radiological technologist were analyzed visually for evaluation of following findings, enhancement of the bile duct wall, dilatation of bile duct tip, liver parenchyma, background suppression. Results : Five dogs was died of a disease after the infection, the rest one else shows the chronic dilatation of the intrahepatic bile duct with CT and MR imaging. Contrast administration of CT shows the contrast-enhanced of the bile duct walls with live parenchyma. MR imaging calculated of CNR and CR from pulse sequence for comparative evaluation and shows the pattern of the intrahepatic bile duct, dilatation of bile duct tip using MIP technique. CNR of the clonorchiasis, HASTE was $16{\pm}0.83$, TSE $7.06{\pm}3.0$, FLASH $1.19{\pm}0.2$ and CR, HASTE was 73.3%, TSE 62.3%, FLASH 6.4%. Conclusion : CT and MR imaging is very usefulness in diagnosis of dog clonorchiasis.