• Korean Journal of Ecology and Environment
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• v.46 no.3
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• pp.319-331
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• 2013

Recent climate change, which is mostly ascribed to anthropogenic activities, is believed to be a major factor leading to biodiversity decreases and ecosystem service deteriorations. I have reviewed recent studies on climate change effects for many ecological processes involved with plants, in order to improve our understanding of the nature of ecological complexity. Plants in general have better growth and productivity under high levels of $CO_2$, although the long term effects of such $CO_2$ fertilizers are still controversial. Over the last 30 years, the Earth has been greening, particularly at higher latitudes of the Northern Hemisphere, perhaps due to a relaxation of climatic constraints. Human appropriation of net primary productivity (NPP), which corresponds up to 1/3 of global NPP, is ultimately responsible for climate change and biodiversity decreases. Climate change causes phenological variations in plants, especially in regards to spring flowering and fall leaf coloring. Many plants migrate polewards and towards higher altitudes to seek more appropriate climates. On the other hand, tree mortality and population declines have recently been reported in many continents. Landscape disturbance not only hinders the plant migration, but also makes it difficult to predict the plants' potential habitats. Plant and animal population declines, as well as local extinctions, are largely due to the disruption of species interactions through temporal mismatching. Temperature and $CO_2$ increase rates in Korea are higher than global means. The degree of landscape disturbances is also relatively high. Furthermore, long-term data on individual species responses and species interactions are lacking or quite limited in Korea. This review emphasizes the complex nature of species responses to climate change at both global and local scales. In order to keep pace with the direction and speed of climate change, it is urgently necessary to observe and analyze the patterns of phenology, migration, and trophic interactions of plants and animals in Korea's landscape.

• Journal of Sericultural and Entomological Science
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• v.13 no.1
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• pp.35-47
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• 1971

Current overseas research reveals that among the pathogens causing flacherie of silkworm, damage by infectious flacherie virus is the most serious, but little research in this fold has been reported in Korea. This experiment was undertaken to observe the occurrence of infectious flacherie virus by means of biological environmental conditions associated with occurrence of virus discase and interaction of the virus of flacherie and Bacillus spp. isolated from flacherie silkworm, and to determine ways to check infection by the virus during the rearing of silkworms. The results obtained are as follows: 1. The pathogen, infectious flacherie virus observed in Korea, is proved to be round in shape and 26-30m$\mu$ in diameter under observation with electron microscope, 2. The infectious flacherie virus-disease occurred apparently in conditions of nutritional disturbance such as shortage of diet or rearing in high temperature and humidity during the 3-4th instar. 3. The percentage of disease-occurrence was increased remarkably, and the latent period was shortened in the case of simple inoculation of virus suspension as compared with the suspension added with bacteria. 4. The application of calcium hydroxide in the silkworm-rearing bed is able to check infection of virus disease.

• Journal of the Korean Institute of Intelligent Systems
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• v.21 no.6
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• pp.737-742
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• 2011

Navigation problems include the task of determining the control input under various constraints for systems such as mobile robots subject to uncertain disturbance. Such tasks can be modeled as constrained stochastic control problems. In order to solve these control problems, one may try to utilize the dynamic programming(DP) methods which rely on the concept of optimal value function. However, in most real-world problems, this trial would give us many difficulties; for examples, the exact system model may not be known; the computation of the optimal control policy may be impossible; and/or a huge amount of computing resource may be in need. As a strategy to overcome the difficulties of DP, one can utilize ADP(approximate dynamic programming) methods, which find suboptimal control policies resorting to approximate value functions. In this paper, we apply recently proposed ADP methods to a class of navigation problems having complex constraints, and observe the resultant performance characteristics.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.22 no.2
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• pp.13-30
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• 2019

The purpose of this study was to investigate changes in vegetation and flora after five years through field surveys data with the Han Gang Watershed Management Committee (2013) data in order to observe natural vegetation changes in the riparian zone of Han River watershed. As a result, the flora of the riparian zone in 2012 were listed total 231 taxa, 66 families, 158 genus, 207 species, 23 varieties, and 1 forms, and in 2017, a total 247 taxa, 74 families, 174 genus, 218 species, 27 varieties, and 2 forms were identified. The number of rare plants decreased from 4 taxa in 2012 to 2 taxa in total in 2017, and the number of endemic plants increased from 1 taxa to 3 taxa. The number of specific plants by floral region decreased from 21 taxa (9.1% of all 231 taxa of flora) in 2012 to 16 taxa (6.5% of all 247 taxa of flora) in 2017. The total number of naturalized plants is analyzed to increase from 35 taxa, a naturalization rate of 15.15% (all 231 taxa of flora) and urbanization index of 11.2% (all 312 taxa of naturalized plants) in 2012 to 44 taxa a naturalization rate of 17.8% (all 231 taxa of flora) and urbanization index of 14.1%(all 312 taxa of naturalized plants) in 2017. The ecosystem disturbance species showed an increase in both number of species and cover degree grades, indicating that the riparian zone changed in a negative direction.

• Medical Lasers
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• v.10 no.1
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• pp.22-30
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• 2021

Background and Objectives Ocular alkali burns cause severe damage to the ocular tissues and vision loss. Solcoseryl is a standardized calf blood extract that normalizes the metabolic disturbance and aids in maintaining the chemical and hormonal balance and has been used to treat burns in various tissues. This study examined the effects of Solcoseryl on a rat corneal alkali burn model. Materials and Methods Twenty rats were assigned randomly to four equal groups, including alkali burn, hyaluronic acid, Solcoseryl eyedrop, and Solcoseryl gel. A corneal alkali burn was induced by a NaOH-soaked paper disc. The treatments were given twice a day, every day. The wound area was measured after 24 and 48 hours, and the degree of neovascularization and corneal opacity were scored every week. The rats were sacrificed after three weeks for immunohistochemistry (IHC) to compare the level of inflammatory cytokines, IL-1β, IL-6, and TNF-α. The thickness of the retinal layers was compared to observe any changes in the retina. Results The use of Solcoseryl on corneal alkali burn accelerated wound healing with less neovascularization, greater opacity, and less cataract. IHC showed that the inflammation of the cornea was controlled by both the hyaluronic acid and Solcoseryl treatments. On the other hand, the inflammation had spread to the retina. When the dosage forms were compared, eyedrops were more effective on corneal inflammation, while the gel-type had a greater effect on retinal inflammation. Conclusion Solcoseryl was effective in accelerating the wound healing rate on a corneal alkali burn but could not prevent the spread of inflammation from the cornea to the retina. Eyedrops were more effective on inflammation in the cornea, and the gel was more effective in the retina.

• Journal of Ginseng Research
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• v.46 no.2
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• pp.296-303
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• 2022

Background: Skin microbiota is important for maintenance of skin homeostasis; however, its disturbance may cause an increase in pathogenic microorganisms. Therefore, we aimed to develop a red ginseng formulation that can selectively promote beneficial bacteria. Methods: The effects of red ginseng formulation on microorganism growth were analyzed by comparing the growth rates of Staphylococcus aureus, S. epidermidis, and Cutibacterium acnes. Various preservatives mixed with red ginseng formulation were evaluated to determine the ideal composition for selective growth promotion of S. epidermidis. Red ginseng formulation with selected preservative was loaded into a biocompatible polymer mixture and applied to the faces of 20 female subjects in the clinical trial to observe changes in the skin microbiome. Results: Red ginseng formulation promoted the growth of S. aureus and S. epidermidis compared to fructooligosaccharide. When 1,2-hexanediol was applied with red ginseng formulation, only S. epidermidis showed selective growth. The analysis of the release rates of ginsenoside-Rg1 and -Re revealed that the exact content of Pluronic F-127 was around 11%. The application of hydrogel resulted in a decrease in C. acnes in all subjects. In subjects with low levels of S. epidermidis, the distribution of S. epidermidis was significantly increased with the application of hydrogel formulation and total microbial species of subjects decreased by 50% during the clinical trial. Conclusion: We confirmed that red ginseng formulation with 1,2-hexanediol can help maintain skin homeostasis through improvement of skin microbiome.

• Korean Journal of Psychosomatic Medicine
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• v.20 no.2
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• pp.112-119
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• 2012

Objectives : Delirium is a disorder defined as a sudden disturbance in thinking, speaking, acting and sleep pattern due to altered level of consciousness and cognitive function. The objective of this study is to analyze characteristics and therapeutic methods of the delirious patients during the recent 5 years, and provide basic data for further studies and investigation regarding delirium in the occurrence and treatment. Methods : We retrospectively reviewed medical records of 475 patients who were consulted for delirium in Kyunghee University Medical Center from January 2007 to December 2011. Results : During the 5 years, among the 475 patients who were diagnosed as delirium, men were more common(61.7%). The most commonly consulted reason and cause were sleep disturbance(80.8%) and post-operational delirium(30.9%), respectively. The medication prescription percentage was 76.6% and was significantly increased year after year. Ratio of using antipsychotics were 76.4% among prescribed medication and the most frequently prescribed antipsychotic drug was quetiapine(46.8%). Other specialists commonly misdiagnosed delirium when the patient was previously diagnosed as dementia(6.8%). Conclusions : In our study, post-operational delirium was the most commonly referred reason and the percentage of medication prescription tended to increase. Patients with history of dementia were more easily misdiagnosed as diseases other than delirium. Our study suggests that we should evaluate symptoms, causes, reasons of consultation, management tendency of delirium. We should also closely observe changes in sleep patterns and establish the prevention strategies for post-operational delirium and therapeutic bases for pharmacotherapy.

• Sleep Medicine and Psychophysiology
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• v.15 no.2
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• pp.71-76
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• 2008

Introduction: In this study, we compared sleep structure, EEG characteristic of pediatric obstructive sleep apnea (OSA) and normal controls which were matched in sex and age. Methods: Fifteen children (male：female=4：11) who complained snoring and were suspected to have sleep apnea and their age and sex matched normal controls (male：female=5：10) have been done nocturnal polysomnography (NPSG). Sleep parameters, sleep apnea variables and relative spectral components of EEG from NPSG have been compared between both groups. Results: Pediatric OSA group were distinguished from normal controls in terms of apnea index, respiratory disturbance index and nadir of oxyhemoglobulin desaturation. Pediatric OSA group showed increased percent of sleep stage 1, decreased rapid eye movement sleep percent and increased delta power in O1 EEG channel. However other sleep parameters and spectral powers were not different between two groups. Conclusion: In pediatric OSA group, sleep structure parameter disruption may be not prominent as the previous studies for adult OSA group because of including mild OSA data in diagnostic criteria. In addition, EEG changes might not be distinct due to low arousal index compared to adult OSA patients. We can observe general characteristics and particularity of pediatric OSA through this study.

• Journal of Navigation and Port Research
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• v.31 no.8
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• pp.629-635
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• 2007

Reduced crew performance is frequently cited as a major causal factor in maritime accident causation. Although considerable research has been conducted on the hours of work undertaken by seafarers through interviews and the analysis of records, experimental studies to observe the effects of factors such as high workload, shift patterns, stress, sleep deprivation and disturbance on the cognitive performance of mariners have been limited. Other safety-critical transport industries, such as aviation and rail, have developed fatigue management tools to help manage the work patterns of their operators. Such a tool for mariners would assist shipboard crew, marine pilots and shore management in planning and improving work schedules. The overall aim of this paper is to determine a fatigue factor, which can be applied to human performance data, as part of a software program that calculates total cognitive performance. This program enables us to establish the levels of cognitive performance of a group of marine pilots to test a decision-making task based on radar information. This paper addresses one of the factors that may contribute to the determination of various fatigue factors: the effect of different work patterns on the cognitive performance of a marine pilot.

• Clinical and Experimental Pediatrics
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• v.48 no.4
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• pp.406-410
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• 2005

Purpose : Anticonvulsants have a number of side effects and some of them may be attributed to a disturbance of serum trace metal homeostasis. Although they are minor building components in tissues, they play important functional roles in the peripheral and central nervous system. We measured serum copper and zinc levels in epileptic children who were treated with anticonvulsants to know the effects of anticonvulsants on serum copper and zinc levels. Methods : Serum copper and zinc levels were determined in 64 epileptic patients receiving anticonvulsant therapy in Chungnam National University Hospital, and in 20 normal controls. Sixty-four epileptic patients were divided into three groups : 16 patients who were treated with valproic acid monotherapy; 26 patients who were treated with valproic acid in addition to other anticonvulsants; and 22 patients who were treated with anticonvulsants except for valporic acid. Results : All patients receiving anticonvulsants had significantly lower serum copper levels($80.21{\pm}19.42{\mu}g/dL$) in comparison to the normal controls($102.12{\pm}32.8{\mu}g/dL$). Serum zinc levels in patients receiving anticonvulsants($79.78{\pm}21.88{\mu}g/dL$) were not statistically different from those of controls ($85.26{\pm}29.81{\mu}g/dL$). There were no significant difference of serum copper and zinc levels among the three groups. Conclusion : In this study, we clearly showed that anticonvulsants decreased serum copper levels. Although we did not observe any clinical findings related to copper deficiency, we should pay attention to potent copper deficiency in patients with anticonvulsant treatment.