• 제목/요약/키워드: ecological variable

검색결과 191건 처리시간 0.026초

도시 및 기후특성이 에너지 회복력에 미치는 영향 - 정전발생시간을 중심으로 - (The Effect of Urban and Climate Characteristics on Energy Resilience - Focusing on Blackout Time -)

  • 이동성;문태훈
    • 국토계획
    • /
    • 제54권4호
    • /
    • pp.122-130
    • /
    • 2019
  • The purpose of this study is to analyze effect of climate and urban factors on energy resilience, and to explore policy alternatives to strengthen resilience of energy system. For this purpose, this study used extensive literature review on resilience studies and multiple regression analysis. In this study, blackout time was set as a dependent variable. And the independent variables were divided into climate and urban (robustness, countermeasure capacity) characteristics. As a result of the analysis, in terms of climate characteristics, maximum wind speed and cooling/heating degree-day have statistically significant impact on blackout time. With regard to urban characteristics, number of consumer, ratio of deteriorated housing and coast dummy variables have statistically significant impact on blackout time. And the ratio of government employees and road ratio were found to be the most influencing factors to shorten time taken to restore original level of electricity supply. Based on the study results, several policy suggestions to improve energy resilience were made such as continuous management of vulnerable areas and strengthening disaster response services. This study only considered engineering dimension of resilience. Further studies need to be approached on ecological & social-ecological dimension.

Spatial distribution of phytoplankton in Gamak Bay in spring, with emphasis on small phytoplankton

  • Yeongji Oh;Yoonja Kang
    • 환경생물
    • /
    • 제40권4호
    • /
    • pp.374-386
    • /
    • 2022
  • Phytoplankton communities, with emphasis on picoplankton and nanoplankton, were investigated in Gamak Bay, South Korea, where freshwater input and coastal water intrusion shape ecosystem functions. Shellfish farms and fish farms are located in the inner bay and outer bay, respectively, and tides translocate uneaten food and urine production from aquaculture farms toward the inner bay. Water masses were distinctly different based on a significantly different density between the surface and bottom layer and among three water masses, including the inner bay, outer bay, and Yeosu Harbor. Phytoplankton communities were quantified using flow cytometry and size-fractionated chlorophyll-a (chl-a) was measured. Salinity was a principal variable separating phytoplankton communities between the surface and bottom layer, whereas Si(OH)4 controlled the communities in the inner bay, and NH4+ and PO43- governed the outer bay communities. While phycocyanin-containing (PC) cyanobacteria dominated in the outer bay, phycoerythrin-containing (PE) cyanobacteria dominance occurred with cryptophyte dominance, indicating that nutrients affected the distribution of pico- and nanoplankton and that cryptophytes potentially relied on a mixotrophic mode by feeding on PE cyanobacteria. Interestingly, picoeukaryotes and eukaryotes larger than 10 ㎛ were mostly responsible for the ecological niche in the western region of the bay. Given that chl-a levels have historically declined, our study highlights the potential importance of increased small phytoplankton in Gamak Bay. Particularly, we urge an examination of the ecological role of small phytoplankton in the food supply of cultivated marine organisms.

농업환경 분야에서 토양 리질리언스 분야별 평가 방법 (Evaluation Methods of Soil Resilience Related to Agricultural Environment)

  • 김민석;민현기;현승훈;김정규
    • Ecology and Resilient Infrastructure
    • /
    • 제7권2호
    • /
    • pp.97-113
    • /
    • 2020
  • 토양은 인간의 삶의 터전이자 식량안보를 책임질 수 있는 근간으로, UN의 지속가능한 개발 목표에서도 중요하게 다루고 있다. 농업환경에서 토양 리질리언스는, 불확실성과 예측불가능성이 높은 시대에 건전하고 지속가능한 토양 관리를 위해 반드시 필요한 연구분야이다. 토양 리질리언스의 정의는 연구자들마다 조금씩 다르나 교란에 대한 회복과 저항 개념을 공통적으로 포함하고 있다. 본 연구에서는 다양한 종류의 교란에 대한 토양 리질리언스의 반응을 평가하기 위하여 사용된 토양의 물리적, 화학적, 생물학적 특성들을 정리하였다. 이어서 토양 리질리언스 연구의 시공간적 범위가 넓은 것에 기인한 다양한 통계 처리 기법들과 리질리언스 정량화 방법들을 정리하였다. 또한 많은 토양 리질리언스 연구들은 공통적으로 (1) 토양 및 부지 선정 (2) 스트레스 및 교란 (독립변수) 설정 (3) 토양 특성 및 지표 (종속변수) 설정 (4) 다양한 시공간적 규모 (scale) 실험 수행 (5) 데이터 통계분석 등 5단계에 걸쳐 수행되어왔음을 확인할 수 있었다. 선행 및 이번 연구를 통해 토양 리질리언스의 일반적 개론을 다루었으며, 이를 바탕으로 국내 농업 환경을 고려한 실질적인 연구가 수행되어야 할 것이다.

생태순간평가를 이용한 성장모형개발: 노년 활력 지수를 활용하여 (Development of Growth Model Using Ecological Momentary Assessment: Based on Senior Vitality Quotient)

  • 전희진;송혜선;이지현;박기호;최기홍;서동기
    • 한국융합학회논문지
    • /
    • 제12권5호
    • /
    • pp.313-326
    • /
    • 2021
  • 본 연구는 EMA 연구방법을 소개하고 연구에 적용하는 방법을 보여주는 것을 목적으로 한다. 노년 활력 증강을 측정하는 지속개발을 위한 사전연구로, 노인의 종단자료를 이용하여 성장모형을 성립하고 분석방법으로써 다층모형의 적합성을 설명하였다. 절편만 존재하는 모형을 통해 종속변수의 총분산을 확인한 결과, 전체분산 중 약 47%는 개인 차이에 의해 발생하였고 53%는 측정 시점 차이에 의해 발생하였다. 두 번째는 일차항을 고정효과로 추가한 모형으로, 시간을 집단평균 중심화하여 노년 활력 지수에 미치는 영향을 개인마다 다르게 확인하였다. 그 결과, 시간에 대한 효과는 유의하지 않았다. 이는 본 연구가 처치를 투입하지 않은 사전연구이기 때문이며, EMA 자료 수집 과정에서 외부개입 없이 변화가 크지 않은 자료를 보임을 의미한다. 세 번째는 성별을 독립변수로 추가한 모형으로, 변화는 시간과 성별 모두에서 유의하지 않은 결과를 보였다. 마지막으로 각 모형에 대한 PRD를 비교해본 결과, 성별변수를 투입하지 않는 모형이 더 효과적으로 자료에 적합함을 보였다. 이는 EMA 연구에서 응답자의 시간과 맥락을 고려하여 개인의 특성을 측정할 수 있는 다층모형을 이용해야 함을 시사한다.

두꺼비 서식지 적합성 지수(HSI) 모델개발을 위한 연구 (A Study on the Development of "Bufo gargarizans" Habitat Suitability Index(HSI))

  • 조근영;구본학
    • 한국환경복원기술학회지
    • /
    • 제25권2호
    • /
    • pp.23-38
    • /
    • 2022
  • This study investigates the characteristics and physical habitat requirements for each Bufo gargarizans life history through a literature survey. After deriving variables for each component of Bufo gargarizans, in order to reduce regional deviations from eight previously studied literature research areas for deriving the criteria for variables, a total of 12 natural habitats of Bufo gargarizanss are selected as spatial ranges by selecting four additional sites such as Umyeonsan Ecological Park in Seoul, Wonheungibangjuk in Cheongju in the central region, Changnyeong Isan Reservoir in the southern region, and Mangwonji in Daegu. This study presents Bufo gargarizans SI, a species endemic to Korea, whose population is rapidly declining due to large-scale housing site development and road development, and develops a Bufo gargarizans HSI model accordingly to improve the function of the damaged Bufo gargarizans habitat and to present an objective basis for site selection of alternative habitat. At the same time, it provides basic data for adaptive management and follow-up monitoring. The three basic habitat requirements of amphibians, the physical habitat requirements of Bufo gargarizans, synthesized with shelter, food, and water, and the characteristics of each life history, are classified into five components by adding space and threats through literature research and expert advice. Variables are proposed by synthesizing and comparing the general characteristics of amphibians, among the previously studied single species of amphibians, the components of HSI of goldfrogs and Bufo gargarizans, and the ecological and physical environmental characteristics of Bufo gargarizans. Afterwards, through consultation with an amphibian expert, a total of 10 variables are finally presented by adjacent forest area(ha), the distance between spawning area and the nearest forest land(m), the soil, the distance from the wetland(m), the forest layered structure, the low grassland space, the permanent wetland area(ha), shoreline slope(%), PH, presence of predators, distance from road(m), presence or absence of obstacles. n order to derive the final criteria for each of the 10 variables, the criteria(alternative) for each variable are presented through geographic information analysis of the site survey area and field surveys of the previously studied literature research area. After a focus group interview(FGI) of 30 people related to the Bufo gargarizans colony in Cheongju, a questionnaire and in-depth interviews with three amphibians experts are conducted to verify and supplement the criteria for each final variable. Based on the finally developed Bufo gargarizans HSI, the Bufo gargarizans habitat model is presented through the SI graph model and the drawing centering on the Bufo gargarizans spawning area

생태체계적 관점에서 본 생애주기별 자살생각의 위험요인과 보호요인 (Risk and Protection Factor Related to Suicide Ideation in Each Life Course based on an Ecological-system Perspective)

  • 김윤정
    • 한국지역사회생활과학회지
    • /
    • 제22권3호
    • /
    • pp.429-444
    • /
    • 2011
  • The objective of this study was to identify the risk factor and protection factor related to suicide ideation in each life course based on an ecological-system perspective. A questionnaire was carried out for 393 adolescents, 473 adults and 376 aged men living nationwide. The results are as follows. First, the suicide ideation was low with 1.78 points in the full mark of 5 points. Second, the difference in suicide ideation, depression, hopelessness, stress in the organic system variables, family solidarity in the micro system variables, intermediate system variables, residence, the existence/inexistence of counselling center and the influence of mass media in mezo system variables in each life course were significant. Third, the relative influence of organic system variables on the suicide ideation were largest in all life courses. Further, the depression and the influence of mass media in all life courses were a risk factor of suicide ideation and stress was also a risk factor of suicide ideation in the case of adolescents and the aged. When examining protection factors of suicide ideation, family solidarity, minute as it is, works as the protection factor of suicide ideation in the case of adolescents. For the adults, living in a metropolis was a protection factor from suicide ideation. For the aged, family solidarity, family history of suicide and adult children's attention to their friends and neighbors (intermediate system variable) were protection factors from suicide ideation. I suggested that policy, service, counseling and educational program proper to each life course were necessary to lower risk factors of suicide ideation and to improve protection factors.

Mitochondrial DNA Sequence Variation of the Oriental Mole Cricket, Gryllotalpa orientalis (Orthoptera: Gryllotalpidae) in Korea

  • Kim, Ik-Soo;Cha, So-Young;Lee, Sun-Young;Kim, Seong-Ryul;Hwang, Jae-Sam;Li, Jianhong;Han, Yeon-Soo;Jin, Byung-Rae
    • International Journal of Industrial Entomology and Biomaterials
    • /
    • 제14권2호
    • /
    • pp.107-112
    • /
    • 2007
  • The mole crickets, Gryllotalpa, are insect pest distributed in the world. In Korea, G. orientalis was reported to occur, but previous ecological studies suggested the presence of two ecological types. To test this hypothesis, we sequenced a portion of mitochondrial (mt) genome from 48 G. orientali individuals collected over five Korean localities: Busan, Suwon, Okchon, Wonju, and Gangneung. From the sequence analysis, only two haplotypes were obtained, but the sequence divergence between the two haplotypes was 11 %, suggesting the presence of two distinct genetic groups in Korea. Although the population of Busan, Okchon, Wonju, and Gangneung was identified as a single haplotype, but that of Suwon was occupied by both hapotypes. Considering sequence divergence of other insect species occurring in Korea, the divergence estimate found between the two haplotypes seems to be too large to be considered as identical species. This result may suggest that the two differentiated haplotypes found in this study may reflect the previously reported two ecological types found in Suwon, Korea. To further understand the genetic divergence of the two phylogenetic groups, analysis of more variable regions of G. orientalis genome is required.

Effects of cultivation ages and modes on microbial diversity in the rhizosphere soil of Panax ginseng

  • Xiao, Chunping;Yang, Limin;Zhang, Lianxue;Liu, Cuijing;Han, Mei
    • Journal of Ginseng Research
    • /
    • 제40권1호
    • /
    • pp.28-37
    • /
    • 2016
  • Background: Panax ginseng cannot be cultivated on the same land consecutively for an extended period, and the underlying mechanism regarding microorganisms is still being explored. Methods: Polymerase chain reaction and denaturing gradient gel electrophoresis (PCR-DGGE) and BIO-LOG methods were used to evaluate the microbial genetic and functional diversity associated with the P. ginseng rhizosphere soil in various cultivation ages and modes. Results: The analysis of microbial diversity using PCR-DGGE showed that microbial communities were significantly variable in composition, of which six bacterial phyla and seven fungal classes were detected in P. ginseng soil. Among them, Proteobacteria and Hypocreales dominated. Fusarium oxysporum, a soilborne pathogen, was found in all P. ginseng soil samples except R0. The results from functional diversity suggested that the microbial metabolic diversity of fallow soil abandoned in 2003was the maximum and transplanted soil was higher than direct-seeding soil and the forest soil uncultivated P. ginseng, whereas the increase in cultivation ages in the same mode led to decreases in microbial diversity in P. ginseng soil. Carbohydrates, amino acids, and polymers were the main carbon sources utilized. Furthermore, the microbial diversity index and multivariate comparisons indicated that the augmentation of P. ginseng cultivation ages resulted in decreased bacterial diversity and increased fungal diversity, whereas microbial diversity was improved strikingly in transplanted soil and fallow soil abandoned for at least one decade. Conclusion: The key factors for discontinuous P. ginseng cultivation were the lack of balance in rhizosphere microbial communities and the outbreak of soilborne diseases caused by the accumulation of its root exudates.

결손가정 아동의 정신건강 구조모형 (A Structural Model on the Mental Health in Children from Dysfunctional Families)

  • 이현주;김희경
    • 한국학교ㆍ지역보건교육학회지
    • /
    • 제13권3호
    • /
    • pp.13-31
    • /
    • 2012
  • Purpose: This study was on the structural analysis of the covariant amount in order to evaluate the suitability of the structural models which can explain and predict the mental health of children on the basis of Bronfenbrenner's ecological theory. Methods: A questionnaire was used to survey 269 children from dysfunctional families out of 5th and 6th grade students from 30 elementary schools in one city and 6 counties, which was analyzed by using PASW Statistics 18.0 and LISREL 8.7 programs. Results: The variable which had influence on the self-esteem was the social support. The variable which had influence on the positive reaction under stress was the stress. The variables which had influence on the negative reaction under stress were stress, and self esteem. The variables which had influence on the mental health were the self-esteem and the negative reaction under stress. The main variables to influence the mental health of children from dysfunctional families turned out to be the self-esteem and the negative reaction under stress to the mental health. Conclusion: Evaluating the suitability of the models, I presented the bases on the practical nursing business. They showed the right directions to the mental health care of children from dysfunctional families.

  • PDF

창호거치 태양광발전 가변형광선반 설계 및 기초적 발전성능에 관한 연구 (A Study on the Design and Power Performance of a Variable Photovoltaic Lightshelf Mounted on the Windows)

  • 정유근
    • KIEAE Journal
    • /
    • 제13권6호
    • /
    • pp.105-111
    • /
    • 2013
  • This study aims to suggest the PV lightshelf and to evaluate the power performance of the photovoltaic systems easily mounted on the windows. For the study, the suggested systems consist of two parts as fixed and movable PV modules. Also, tempered glass and polycarbonate are used on the surface protection materials for solar cells of PV lightshelf. By using polycarbonate, the weight of PV lightshelf is lighter about 20%. The field tests are performed for five days by using real size models. The voltage, current and electric powers are measured as basic performances of PV lightshelf. Also, the irradiation, brightness and module surface temperature are measured as outside conditions. As results, the power performance of tempered glass PV lightshelf shows about 11(%) higher thant that of polycarbonate PV lightshelf. And the power performance shows about 5(%) higher in a horizontal system. This results could be used to develop the effective PV lightshelf in next study.