• Title/Summary/Keyword: disturbance factor

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Vegetation Characteristics of Geumnamhonam·Honam Ridge Areas Understood through Quantitative Vegetation Analysis (정량적 식생분석을 통한 금남호남·호남정맥 마루금 일대의 식생 특성)

  • Park, Seok-Gon;Kang, Hyun-Mi
    • Korean Journal of Environment and Ecology
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    • v.34 no.4
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    • pp.304-317
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    • 2020
  • This study conducted selected two sites in Geumnamhonam and four sites in Honam-Jeongmaek for vegetation survey with consideration to the location environment and anthropogenic impacts to investigate the vegetation structures of the Geumnamhonam-Jeongmaek·Honam-Jeongmaek ridge areas. Using TWINSPAN (two-way indicator species analysis), each of the two ridge areas were categorized into seven plant communities. The differential species in the TWINSPAN technique indirectly represent the environmental factors of plant communities, and the community types of the two ridge areas were divided based on environmental factors such as altitudes above sea level, soil moisture, and disturbance. These results were in harmony with the environmental factors of the DCA (detrended correspondence analysis) axis 1. In the low-lying areas of both ridge areas, afforestation tree species such as Pinus rigida and P. thunbergii were in competition with native tree species. As such, in the low-lying areas, artificial vegetation disturbance was severe due to afforestation and development projects. In relatively highland areas, such as upper slopes, and top areas, in the ridge, the vegetation type with the dominance of Quercus mongolica, Q. variabilis, and P. densiflora was preserved well. As for differences between the two ridge areas, communities dominated by Q. mongolica were distributed widely in Geumnamhonam-Jeongmaek because of the altitudes above sea level, and the latitude of this ridge area are higher than those of Honam-Jeongmaek. On the other hand, communities dominated by P. densiflora were distributed along with communities dominated by Q. mongolica, and communities dominated by Q. variabilis appeared in Honam-Jeongmaek because it is adjacent to the south coast. In quantitative vegetation analysis such as TWINSPAN and DCA, changes in species composition and the extracting environmental factors that cause the changes are important. To that end, the removal of accidental emergent species, the establishment of an investigation plan that assumes environmental factors, and the selection of the optimal analytical method suitable for the characteristics of the survey data are necessary.

Analysis to Recognition of School Health Promotion Applied ACCESS Model (초등학교 양호교사의 학교건강증진 인식도 연구- ACCESS모델을 적용 -)

  • Kang, Mal-Soon;Kim, Jung-Nam;Ryu, Mi-Kyung
    • Research in Community and Public Health Nursing
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    • v.11 no.2
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    • pp.577-590
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    • 2000
  • This study is basic research for developing health promotion programs in elementary school and is looking at the effect factor of School nurses perception and school health promotion. This study was conducted with the ACCESS model for school health promotion from WHO. The subjects of this study were 28 elementary school nurses located in the west side of Kung-Nam from the 7th of June to the 30th of June by direct interview. The results of this study are summarized as follows: 1. the score from obesity, dental caries, health counselling, scoliosis, hepatitis B, immunization BCG items are higher in the low grade but showed significant difference in visual disturbance items. 2. the average score of school health promotion perception is 5.04. The list of school health promotion is composed of school health policies(5.39), physical environments (5.38), school health services(5.34), social environments (5.22), personal health skills (4.92), and community relationships(4.64). 3. after an analysis of the perception of school health promotion from school nurses, the relationship between the school health budget and the school health policy and school health service was shown to be significant. 4. after analysis of the effect factor of perception of school health promotion from school nurses, school health policy, school social environment, personal health skills, and school health service were shown to be significant. 5. The factors in school health promotion are the number of classes and students, school budgets, school nurses' final education and age, health education classes per week, and teaching experience. Particularly the school health budget and school nurses of the classes per week are statistically significant. The suggestions of this study are as follows: 1, as a related factor of school health promotion. the generally characteristics of schools and school nurses should be considered for improving the perception of school health promotion. 2, the period of health education for effective school health management and health education should be an on-going program. 3. the scope of school health promotion and perception should be considered for developing health promotion programs. 4. elementary school health promotion programs should be developed and applied to research. 5. computer system programs should be developed for effective school health projects.

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Standardization and Reliability and Validity of the Korean Edition of Profile of Mood States(K-POMS) (한국판 기분상태척도(K-POMS)의 표준화와 신뢰도와 타당도 평가)

  • Kim, Eui-Joong;Lee, Sang-Ick;Jeong, Do-Un;Shin, Min-Sup;Yoon, In-Young
    • Sleep Medicine and Psychophysiology
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    • v.10 no.1
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    • pp.39-51
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    • 2003
  • Objectives: The Profile of Mood States (POMS) has been used broadly and frequently in various medical studies with various subjects. For the development and application of the Korean edition of POMS, called K-POMS, we translated POMS into Korean and then evaluated the reliability and validity of K-POMS. Methods: The subjects were 161 male students with a mean age of 18.1 years (15-30) and 244 female students with a mean age of 16.6 years (14-23). They were requested to perform K-POMS and SCL-90-R (Korean version) at the same time. Means, reliability coefficients, and test-retest correlations of K-POMS were calculated. Content validities, correlations with SCL-90-R, and discrimination validities in comparison with 76 depressive patients were obtained, and factor analyses were carried out. Results: Mean scores of Total Mood Disturbance (TMD) and some subscales (T, F, C, V factor) showed a significant difference between male and female students. The internal consistency coefficient ($\alpha$) of the total 65 items was 0.93, and ranged from 0.67 to 0.90 for subscales. Test-retest correlations of 43 subjects ranged from 0.27 to 0.63. Seven psychiatrists rated the properness of the content of each item as more than moderate degree (mean scale points=2.66, in the range of 0 to 4). Every subscale of KPOMS exhibited significant correlation with the matching subscale of SCL-90-R. Mean scores of K-POMS of the total 405 subjects were significantly different from those of the 76 depressive subjects after age correction. Six factors were extracted, accounting for 51.2% of total variance. Factor 6 consisted of 6 items which came from various subscales of POMS and represented "uncertainty and helplessness," which may be somewhat different to depression or sadness proper. Conclusion: The validity and reliability of K-POMS could be confirmed. The significant difference in K-POMS scores between depressive subjects and normal subjects suggests that K-POMS can be used clinically for the evaluation and screening of depression. The main structure of K-POMS is very similar to that of POMS, except the Confusion-Bewilderment factor which shows weak factor consistency in K-POMS. This may reflect some emotional characteristic of Koreans such as an undifferentiated aspect of cognitive efficiency. The sixth factor newly extracted from K-POMS also may be indicative of an unique emotional aspect of young Koreans.

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The Survey on Actual Condition Depending on Type of Degraded area and Suggestion for Restoration Species Based on Vegetation Information in the Mt. Jirisan Section of Baekdudaegan (식생정보에 기초한 백두대간 지리산권역 내 훼손지 유형별 실태조사)

  • Lee, Hye-Jeong;Kim, Ju-Young;Nam, Kyeong-Bae;An, Ji-Hong
    • Korean Journal of Environment and Ecology
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    • v.34 no.6
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    • pp.558-572
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    • 2020
  • The purpose of this study was to classify the types of degraded areas of Mt. Jirisan section in Baekdudaegan and survey the actual condition of each damage type to use it as basic data for the direction of the restoration of damaged areas according to damage type based on the vegetation information of reference ecosystem. The analysis of the Mt. Jirisan section's actual degraded conditions showed that the total number of patches of degraded areas was 57, and the number of patches and size of degraded areas was higher at the low average altitude and gentle slope. Grasslands (deserted lands) and cultivated areas accounted for a high portion of the damage types, indicating that agricultural land use was a major damage factor. The survey on the conditions of 14 degraded areas showed that the types of damage were classified into the grassland, cultivated area, restoration area, logged-off land, and bare ground. The analysis of the degree of disturbance (the ratio of annual and biennial herb, urbanized index, and disturbance index) by each type showed that the simple single-layer vegetation structure mostly composed of the herbaceous and the degree of disturbance were high in the grassland and cultivated land. The double-layer vegetation structure appeared in the restoration area where the pine seedlings were planted, and the inflow of naturalized plants was especially high compared to other degraded areas due to disturbances caused by the restoration project and the nearby hiking trails. Although the inflow of naturalized plants was low because of high altitude in bare ground, the proportion of annual and biennial herb was high, indicating that all surveyed degraded areas were in early succession stages. The stand ordination by type of damage showed the restoration area on the I-axis, cultivated area, grassland, logged-off land, and bare ground in that order, indicating the arrangement by the damage type. Moreover, the stand ordination of the degraded areas and reference ecosystem based on floristic variation showed a clear difference in species composition. This study diagnosed the status of each damage type based on the reference ecosystem information according to the ecological restoration procedure and confirmed the difference in species composition between the diagnosis result and the reference ecosystem. These findings can be useful basic data for establishing the restoration goal and direction in the future.

Ecological Comparisons of Stream Conditions Between the Unimpacted and Impacted Sites: Case Study

  • Lee, Jae-Hoon;Lee, Sang-Jae;An, Kwang-Guk
    • Korean Journal of Ecology and Environment
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    • v.41 no.4
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    • pp.441-448
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    • 2008
  • The purpose of this study was to analyze chemical water quality, fish trophic guilds, tolerance indicators, and fish community conditions in the Gap Stream and to compare the stream conditions between the unimpacted site and impacted site. This study was conducted in the physically stable season (May 2008) to minimize physical impacts such as flow and hydrological disturbance, and applied the study in the Gap Stream with two sites of unimpacted upstream site (Unim-S), mainly surrounded by forested area and impacted site (Im-S), influenced by the wastewater disposal plants and industrial complex in the urban region. Chemical data analysis showed that the degree of organic matter pollution, based on BOD, and COD, was $2{\sim}3$ fold greater in the Im-S than the Unim-S, and that TP, as eutrophication indicators, was 4.7 fold greater in the Im-S. Also, $NH_3-N$ was in 8.2 fold greater in the Im-S ($6.25\;mg\;L^{-1}$) than the Unim-S ($0.76\;mg\;L^{-1}$), indicating a massive influence of wastewater from the disposal plant. Similar results were found in other chemical parameters. Thus, chemical impacts in the Im-S were evident, compared to the unimpacted site. Evaluations of tolerant indicator species indicated that sensitive species were dominant in the Unim-S (23.9%) and tolerant species were dominant (97.8%) in the Im-S. Condition factor (CF) was averaged 0.95 ($0.68{\sim}1.18$) in the Unim-S and 1.08 ($0.93{\sim}1.22$) in the Im-S. Fish community in the Unim-S and Im-S was categorized as Zacco-community and Hemibarbus-community, respectively, and the community diversity index (H') was significantly (p<0.05) higher in the Unim-S (0.810) than the Im-S (0.466). Overall, our results suggest that the comparison approach of various chemical and ecological indicators provide important information in identifying multiple stressors in the stream ecosystems.

Initial Responses of Quercus serrata Seedlings and Forest Understory to Experimental Gap Treatments

  • Cho, Yong-Chan;Kim, Jun-Soo;Lee, Chang-Seok;Cho, Hyun-Je;Bae, Kwan-Ho
    • Journal of Ecology and Environment
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    • v.32 no.2
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    • pp.87-96
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    • 2009
  • Pinus thunbergii plantations in Pohang-si, Gyeongsangbuk-do, Korea, are of low ecological quality, with arrested succession and a high proportion of ruderal species. To improve the quality of the habitat, we created canopy gaps ($\sim42\;m^2$) and monitored changes in abiotic (light availability, canopy openness) and biotic (survival and growth of seedlings and understory communities) variables in 2007 and 2008 in plots that had received one of five types of treatment: cutting of canopy trees and removal of the understory (CU), cutting of canopy trees only (C), girdling of canopy trees and removal of the understory (GU), girdling of canopy trees (G) or control. Each treatment was applied to three replicate plots. Abiotic variables did not significantly differ among treatments. Survival rates of target species were slightly lower in the CU, G and control conditions. Based on logistic regression analysis, the only significant growth factor affecting survival was height growth. Positive effects of seedling height and leaf area growth on survival were also detected, but did not reach statistical significance. In treatment G, gradual improvement of overstory conditions and mitigation of competition by limitation of disturbance to the understory community were likely to have promoted seedling growth. There were no significant effects of gap treatments on changes in species abundance (cover and richness) and composition of understory between the study years. This result implies that the small gaps created in our study may be below the threshold size to affect understory growth. However, the results of this study are based on a short-term investigation of only two years. Long-term research is strongly recommended to clarify the effects of gap treatment on plant communities in afforested areas.

A Study on the Vegetation Ecological Characteristics and Management of Ansan Reclaimed Wetlands (안산 간척 습지의 식생 생태적 특성 및 관리에 관한 연구)

  • Kim, Kee-Dae
    • Korean Journal of Environment and Ecology
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    • v.21 no.4
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    • pp.318-335
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    • 2007
  • Floral study and present vegetation survey were conducted at a representative reclaimed wetland located behind the Rural Research Institute at Ansan, Gyeonggi-do. The importance values were calculated from the ground cover and frequency of recorded species within quadrats and detrended canonical correspondence analysis was conducted using environment variables, such as total nitrogen, electric conductivity, available phosphate, nitrate nitrogen and the distance from the inner roads. And basal areas for the trees encroaching on the reclaimed wetland were estimated to take a look at the on-going situation about the succession routes on land. As a result, 46 families and 158 species of plants were recorded and Pragmites communis was found to be a dominant species as the present vegetation. The ordination analysis results showed that species distribution was purposely explained by total nitrogen in soil and its content in nitrate nitrogen. The invasion of Robinia pseudoacacia and Pinus rigida whose basal areas were $22.3m^2$ and $1.6m^2$ respectively, into the interior areas of the reclaimed wetland was found to cause a disturbance making some parts of the wetland into land. The zoning program using water level control and migratory roads is becoming a contributing factor in destroying a wetland, so it's suggested that some adjustments should be needed to take care of it.

P-y Curves from Large Displacement Borehole Testmeter for Railway Bridge Foundation (장변위공내재하시험기를 이용한 철도교 기초의 P-y곡선에 관한 연구)

  • Ryu, Chang-Youl;Lee, Seul;Kim, Dae-Sang;Cho, Kook-Hwan
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.836-842
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    • 2011
  • The lateral stability of bridge foundations against train moving load, emergency stopping load, earthquakes, and so on is very important for a railway bridge foundation. A borehole test is much more accurate than laboratory tests since it is possible to minimize the disturbance of ground conditions on the test site. The representative borehole test methods are Dilatometer, Pressuremeter and Lateral Load Tester, which usually provide force-resistance characteristics in elastic range. In order to estimate P-y curves using those methods, the non-linear characteristics of soil which is one of the most important characteristics of the soil cannot be obtained. Therefore, P-y curves are estimated usually using elastic modulus ($E_O$, $E_R$) of lateral pressure-deformation ratio obtained within the range of elastic behavior. Even though the pile foundation is designed using borehole tests in field to increase design accuracy, it is necessary to use a higher safety factor to improve the reliability of the design. A Large Displacement Borehole Testmeter(LDBT) is developed to measure nonlinear characteristics of the soil in this study. P-y curves can be directly achieved from the developed equipment. Comparisons between measured P-y curves the LDBT developed equipment, theoretical methods based on geotechnical investigations, and back-calculated P-y curves from field tests are shown in this paper. The research result shows that the measured P-y curves using LDBT can be properly matched with back-calculated P-y curves from filed tests by applying scale effects for sand and clay, respectively.

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Factors Influencing Quality of Life during Chemotherapy for Colorectal Cancer Patients in South Korea (항암화학요법을 받고 있는 한국 대장암 환자의 삶의 질 영향 요인)

  • Baek, Yongae;Yi, Myungsun
    • Journal of Korean Academy of Nursing
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    • v.45 no.4
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    • pp.604-612
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    • 2015
  • Purpose: The purpose of this study was to investigate the levels of physical symptoms, anxiety, depression, and quality of life (QOL) during chemotherapy for colorectal cancer patients in South Korea and to identify factors influencing their QOL. Methods: Data were collected from 144 colorectal cancer patients receiving chemotherapy during 2012 at one general hospital located in Seoul. Physical symptoms were measured by the M. D. Anderson Symptom Inventory-Gastrointestinal Cancer Module, and anxiety and depression were measured by the Hospital Anxiety Depression Scale. QOL was measured by the Functional Assessment of Cancer Therapy-Colorectal. Data were analyzed using descriptive statistics, t-test, one-way ANOVA, $Scheff{\acute{e}}$ post hoc test, Pearson correlation and stepwise multiple regression. Results: Mean age of the participants was 56.6 and most of them were not employed. In terms of cancer stage, 38.2% were in stage 3, followed by stage 4 (34.7%). The most frequent symptom was lack of appetite, followed by sleep disturbance and fatigue. The mean score for anxiety was 5.40 with a prevalence of 23% and that of depression 8.85 with a prevalence of 64.6%. The mean score for quality of life was 81.93 out of 136 and 75.3% of the variance in QOL was explained by depression, symptoms, anxiety, treatment place, and occupational status. Depression was the strongest predictive factor. Conclusion: Oncology professionals need to pay special attention to relieving depression as well as physical symptoms to improve QOL during chemotherapy for colorectal cancer patients.

System Design for Real-Time Measuring of Power Quality and Harmonics Distortion using Digital Signal Processor (Digital Signal Processor를 이용한 실시간 전력 요소와 왜율 측정 시스템 설계)

  • kim, Geun-Jun;Kang, Bongsoon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.7
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    • pp.1283-1289
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    • 2016
  • Electrical energy is the essential resource for modern society. Recently, the demand for power was significantly increased. Increase of power demand has lead to a decrease in the power quality. Power quality in modern society has been an important factor that can cause a major problem throughout the home and general industry. Therefore, we need a system for preventing the power quality problems. To avoid power issues, it is important that the measurement of the power quality and initial response. In this paper, we propose real-time power quality measurement system and harmonics monitoring system. We design the system using DM240001 board include dsPIC33FJ256GP710A of microchip. This system can adapt three-phase three-wire system. And optimized the algorithm, we can measure momentary changes of the power system. In addition, designed system can measure harmonics distortion like to VTHD, ITHD and ITDD for 31th harmonics.