• Korean Journal of Environment and Ecology
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• v.29 no.2
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• pp.228-235
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• 2015

Stream ecosystems are closely related to many human activities. Therefore, streams are affected by anthropogenic disturbances such as riverine development and gravel-mining as well as deterioration of water quality. The goal of this study was to elucidate the recolonization process of the macroinvertebrate community after a small-scale anthropogenic disturbance. Field studies were conducted at three sites in a natural stream. The number of recolonizing species tended to increase slightly over time, exceeding the total species number of the control. Ephemeroptera contributed the most to shaping the recolonizing pattern of the entire community. From the result of changes in dominant species, the early recolonizers of each site were the species that showed more frequent occurrence particulary at each sites. But the late recolonizers are Chironomidae at all the sites commonly. This result implies that the actual differences exist among the recolonizing trends of each benthic macroinvertebrate taxon. Collector-gatherers and scrapers comprised about 70% of the recolonizing species. These results indicate that the recolonizing process of an aquatic community after an artificial disturbance depends on the environmental conditions(particularly substratum composition or organic pollution) of the habitat.

• KCID journal
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• v.17 no.2
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• pp.42-48
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• 2010

This study was carried out to investigate the changing of benthic macrobenthos community in Saemangeum subtidal area. The distribution of macrobenthic community is important to assume the benthic environment in study area. Macrobenthic community was investigated three times in 2007 (March, June and September) in the Saemangeum subtidal area. The mean density of macrobenthos was $345{\sim}838ind./m^2$ and the most dominant taxa was benthic polychaete. Opportunistic species such as E.cordatum, T.fragilis, H.filiformis, and Tharyx sp. were shown high appearance rate in study area. The dominance of these opportunistic species suggest that the benthic environment of study area was unstable due to environmental disturbance. But, there are only few point that these species were recorded high densities, and also equilibrium species was dominant, too. It means disturbance and un stability of benthic environment in Seamangeum was not serious yet. so the dynamics and trends of these opportunistic species should be concerned.

• The Korean Journal of Ecology
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• v.16 no.1
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• pp.75-91
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• 1993

Structure and dynamics of Abies koreana community in Mt. Gaya were studied to provide the basic data for conservation of Abies koreana community, an endemic species in Korea. A. koreana community of this study site was composed of tree layer (4~7m), subtree layer (2~4m), shrub layer (1~2m), and herb layer (below 1m). The heights of tree and subtree layers were low. Floristic composition showed that this study site was subalpine and dry site. In frequency distribution diagram of diameter classes of major species consisting of A. koreana community, those of both A. koreana and other species showed reverse J-shaped types. From these results, it was estimated that A. koreana community of this site might be maintained continuously as a stable climax state like present state. In the spatal distribution diagram of major species, saplings of A. koreana were established under the canopy of A. koreana and Pinus koraiensis and under the dead tree of A. koreana. From these results, it was known that A. koreana saplings were recruited before the community was disturbed and regeneration was accomplished by advance regeneration pattern, in which these saplings established before occurrence of disturbance fill with open site originated from death of mature tree. Growth of annual rings was variable among individuals, it was estimated that such variation was originated in that growth of each individual relates to microclimatic conditions rather than macroclimatic ones. Ecological longevity of A. koreana in this study site estimated by disturbance types and age of dead trees was about 120 years.

• Korean Journal of Adult Nursing
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• v.25 no.2
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• pp.183-193
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• 2013

Purpose: The purpose of this study was to identify the prevalence and risk factors of sleep disturbance among community dwelling adults in Korea. Methods: Data were collected from nine hundred fifty nine adults dwelling in a metropolitan city in Korea. Subjects were older than 45 years, did not take medication for sleep problems on a regular basis, and did not work at night. The Pittsburgh Sleep Quality Index was used to collect data about sleep disturbance. Sociodemographic, life style, and health related factors were included as risk factors. Chi square test and logistic stepwise regression were used to identify the risk factors. Results: The prevalence of sleep disturbance was 13.1%. The significant risk factors were being female, age, number of toilet use at night, perceived health, and pain. Risk factors were somewhat different by gender. Emotional and job status were the risk factors only for men and menopausal status were for women. Conclusion: Prevalence of sleep disturbance in community dwelling adults in Korea was not greater than those dwelling in other countries. Females, older adults, the number of toilet use at night, perceived health, and pain were the most important risk factors for sleep disturbances. Gender was a factor in reported sleep disturbances. It might be useful to investigate the factors that contribute to the number of toilet use at night as this might have some underlying factors that could be corrected.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.9
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• pp.960-966
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• 2009

The World Health Organization(WHO) has reported the sleep disturbance as one of the adverse effects of noise. And the effect of combined noise sources on human have been investigated because community noises are seldom heard and are concurrent. Therefore, the effects of combined noise source and its S/N ratio on sleep disturbance were investigated; as a single noise source, road traffic noise was selected, and construction and movie noise were combined with road traffic noise. Tests for sleep disturbance were conducted in bedrooms and the effect on each subjects' sleep was evaluated by questionnaire. The results showed that the rate of awakening increased slightly only when the SPL of construction noise was 10 dB higher than that of road traffic noise. It was also found that the sleep disturbance was affected by the type of combined noise sources and its S/N ratio.

• Journal of Ecology and Environment
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• v.34 no.4
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• pp.347-355
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• 2011

Effects of forest thinning on community level properties have not been understood yet in Korea. We investigated regeneration patterns and trajectories after a disturbance by applying a chronosequence approach. Light availability, litter and woody debris cover, and species composition were determined for twenty 50 m line-transect samples representing a disturbance duration gradient (within 11 years). Environmental factors such as light availability and coverage of woody debris and litter changed abruptly after thinning and then returned to the pre-disturbance state. Although species richness was gained at shrub and ground layer in a limited way in both forests, cover of various functional types revealed diversity in their responses. Notably, Alnus firma stands exhibited a larger increment of cover in woody plants. Ordination analysis revealed different regeneration trajectories between natural and planted stands. Based on ordination analysis, rehabilitated stands showed movement to alternative states compared with natural ones, reflecting lower resilience to perturbation (i.e., lower stability). Our results suggest that community resilience to artificial thinning depends on properties of the dominant species. But to get more explanatory ecological information, longer-term static observations are required.

• Journal of Microbiology and Biotechnology
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• v.29 no.12
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• pp.1993-2005
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• 2019

Thermophilic anaerobic digestion (TAD) is characterized by higher biogas production rates as a result of assumedly faster microbial metabolic conversion rates compared to mesophilic AD. It was hypothesized that the thermophilic microbiome with its lower diversity than the mesophilic one is more susceptible to disturbances introduced by alterations in the operating factors, as an example, the supply of nitrogen-rich feedstock such as poultry manure (PM). Laboratory scaled TAD experiments using cattle slurry and increasing amounts of PM were carried out to investigate the (in-) stability of the process performance caused by the accumulation of ammonium and ammonia with special emphasis on the microbial community structure and its dynamic variation. The results revealed that the moderate PM addition, i.e., 25% (vol/vol based on volatile substances) PM, resulted in a reorganization of the microbial community structure which was still working sufficiently. With 50% PM application, the microbial community was further stepwise re-organized and was able to compensate for the high cytotoxic ammonia contents only for a short time resulting in consequent process disturbance and final process failure. This study demonstrated the ability of the acclimated thermophilic microbial community to tolerate a certain amount of nitrogen-rich substrate.

• Women's Health Nursing
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• v.20 no.3
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• pp.195-203
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• 2014

Purpose: The objective of this study was to investigate the relationship between fatigue, sleep disturbance, and gestational stress in women during late stage of pregnancy. Methods: This study was conducted with 113 healthy pregnant women at gestational age greater than 27 weeks who were registered at community health centers and received prenatal care. A structured questionnaire regarding fatigue, sleep disturbance, and gestational stress was used. The data was analyzed using a t-test, an ANOVA, and Pearson correlation coefficients. Results: The subjects with unplanned pregnancies and irregular exercise patterns showed a higher level of fatigue than those with planned pregnancies and regular exercise patterns. Pregnant women with caffeine intake manifested higher levels of gestational stress and sleep disturbance than those without. The levels of sleep disturbance and gestational stress increased as the fatigue levels increased. The fatigue levels increased with increased levels of sleep disturbance. Conclusion: Planned pregnancy, regular exercise patterns, and caffeine intake were related with fatigue, sleep disturbance, and gestational stress in women during late stages of pregnancy. Fatigue, sleep disturbance, and gestational stress had close associations to each other. In the future, such results should guide development of nursing intervention programs for women in late stages of pregnancy.

• The Korean Journal of Ecology
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• v.21 no.2
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• pp.139-149
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• 1998

The Catba national park (20$\circ$42'-20$\circ$54'N, 106$\circ$54'-107$\circ$09'E), which is a representative protected area in northeast Vietnam, was first investigated in terms of phytosociology of the Zurich-Montpellier School. 15 plant communities were identified from the seven vegetation types: Teetaria-Amoora gigantea community, Blechmum-Pitecellobium ferrugineum community, Impatiens-Dracaena cambodiana community, Rhizophora apiculata community, Avicenia marina community, Panicum repens community, Heterosmilax-Zanthoxylum nitidum community, Stachytarphyta jamaiensis-Bidens bipinnata community, microstegium vagans community, Dicranopteris linearis community, Randina-Sapium sebiferum community, Psidium gujava community, Elephantopus scaber community, and chirita aratformis community. Traditional pasturing and shifting agrie\culture by indigenous people in Catba national park were recognized as main disturbance regies, which have been far above sustainable levels. Ecological strategies for conservation and sustainable use on national park' ecosystem were proposed: (1) development of awareness program on sustainable life style of indigenous people, (2) establishment of multiple use module system of national park, (3) ecosystem monitoring of permanent ecological sites.

• Research in Community and Public Health Nursing
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• v.13 no.4
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• pp.608-617
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• 2002

The purpose of this study was to analyze phenomena and characteristics of family nursing in Korea based on the study by Yun et al. (1999) by ICNP. The subjects of this study were 115 reports on family nursing care in Korea National Open University. The results of this study were as follows; 1. In the phenomenon of family nursing, 'Inappropriate family coping' comprised of 17.0% and 'Inadequate care for a sick member' comprised of 16.8%. 2. It was found that 'A few close neighbors was 62.5%, 'Lack of communication between married couple' was 60.0%, 'Neglet of general child rearing' was 40.9%, 'Closed communication pattern of the head of a family' was 36.0%, and 'Inadequate distribution of each family member's role' was 27.2%. 3. 'Lack of family interaction in community' and 'Social isolation' were combined with 'Lack of family interaction in community', and 'Disturbance in family communication' and 'Lack of family intimacy' were combined with 'Disturbance in family communication'. 4. 'Dual-loading with office work and housework', 'Overload of caring one's elders because of the status as a dual-income family' and 'Lack of family support system' were added into 'Inappropriate family coping'.