• 한국작물학회지
• /
• 제42권2호
• /
• pp.146-152
• /
• 1997

Development of shoot and root, leaf water potential and photosynthetic rate affected by water stress in early growing stage of tobacco were surveyed to interpret stress response in terms of plant physiological and agricultural aspects. The growth of shoot and root was highly suppressed by water stress and the difference in dry weight by rewatering was smaller in root than in shoot. The total root length was highly decreased by water stress and the lengths of root for water stress and non-stress were 74m and 84m, respectively, after rewatering. The root growth treated by water stress was increased between 2nd and 3rd day after treatment indicating that temporary water stress at early growing stage might have increased of root zone activity for early growth stage. The leaf water potentials were decreased to -7.63MPa, -9.47MPa, -11.89MPa, -13MPa at the 2nd, 3rd, 4th and 5th day by water stress. The relative water contents were 75%, 62% and 57% at the 3rd, 4th and 5th day after treatment. Photosynthesis was reduced largely by water stress. The photosynthetic rate after treatment at 2nd day and 3rd day was dropped to 18.15$\mu$mol. $CO_2$/$m^2$ㆍsec$^{-1}$ and 9.35$\mu$mol. $CO_2$/$m^2$ㆍsec$^{-1}$. It was never recovered to the normal, even after rewatering. Stomatal conductance had been reduced since 2nd day after treatment and increased after rewatering.

• 한국산학기술학회논문지
• /
• 제15권3호
• /
• pp.1424-1435
• /
• 2014

본 연구는 유아교사의 직무스트레스, 교수효능감, 조직몰입의 관계를 밝히는 데 목적을 두고, 특히 유아교사의 직무스트레스가 조직몰입에 미치는 영향에 있어 교수효능감의 매개효과를 살펴보고자 하였다. 이를 위해 D광역시 소재 유치원과 어린이집 유아교사 각 250명씩 총 500명을 대상으로 설문을 실시하였고, 그중 442부를 회수하여 426사례를 분석에 사용하였다. 연구결과, 유아교사의 직무스트레스는 교수효능감 및 조직몰입과 부적 상관관계를 보였으며, 교수효능감은 조직몰입과 정적 상관관계를 보였다. 또한 유아교사의 교수효능감은 직무스트레스와 조직몰입 간의 관계에서 부분 매개효과를 가지는 것으로 나타났다. 본 연구는 유아교사의 소진을 설명하고자 직무스트레스를 바라보는 방식에서 그 방향을 전환하여, 긍정적 관점인 조직몰입을 설명하기 위한 예측변인으로서 직무스트레스를 바라보았다는 데 의의가 있으며, 교수효능감의 매개효과를 확인함으로써 환경적 개입에 대한 가능성을 제공하였다.

• 한국보육지원학회지
• /
• 제10권1호
• /
• pp.131-146
• /
• 2014

본 연구에서는 유아교사의 자아탄력성과 전문성인식이 직무스트레스에 미치는 영향을 알아보고자 하였다. 이를 위하여 대전광역시에 소재한 어린이집 교사 79명, 유치원 교사 75명, 총 154명을 연구대상으로 선정하였다. 연구도구는 자아탄력성 척도(심순애, 2007), 전문성인식 질문지(이경, 2001), 직무스트레스 질문지(김남희, 1992)를 사용하였다. 본 연구의 결과를 보면, 첫째, 유아교사의 자아탄력성과 직무스트레스의 상관은 각 변수 간의 관련성이 높았으며, 자아탄력성의 하위요인 모두가 직무스트레스와 상관이 있었다. 또한, 유아교사의 전문성인식과 직무스트레스 간의 관계는 유아교사직이 전문적지식과 기술을 요구하는 전문직이라는 인식이 높고 사회경제적 지위가 낮다고 인식할수록 직무스트레스가 높은 것으로 나타났다. 둘째, 유아교사의 직무스트레스에는 자아탄력성의 낙관적인 태도와 분노조절 요인이 유의한 영향을 미쳤으며, 설명변량은 23%였다. 셋째, 유아교사의 직무스트레스에는 전문성 인식 중 전문적지식과 기술요구와 사회 경제적 지위가 유의한 영향을 미쳤으며, 설명변량은 13%였다. 넷째, 유아교사의 자아탄력성과 전문성인식이 직무스트레스에 미치는 상대적 영향력을 살펴본 결과, 유아교사의 낙관적인 태도(자아탄력성), 전문적지식과 기술요구(전문성인식), 사회경제적인 지위(전문성인식), 분노조절(자아탄력성)이 유의한 영향을 미쳤으며, 설명변량은 28%였다. 이와 같은 결과는 유아교사의 긍정적인 사고와 태도를 향상시킬 수 있는 지원체계를 체계적으로 마련할 필요가 있음을 시사한다.

• 문화기술의 융합
• /
• 제8권1호
• /
• pp.39-49
• /
• 2022

유아교사는 영아 또는 어린이를 돌보고 육아하는 선생님으로서 다양한 돌봄을 제공하는 역할을 한다. 본 연구는 코로나 19 상황에서 유아교사의 긍정심리자본이 직무스트레스를 통해 유아교사의 행동 태도에 어떠한 영향을 미치는 지에 대해 그 상관관계를 규명하고자 하는 것이 본 연구의 목적이다. 이에 유치원 교사와 어린이집 교사 220명을 대상으로 하여 2021년 10월 1일부터 10월 14일까지 온라인 설문을 통해 진행하였다. 기록내용 누락 등의 설문지 20부를 제외하고 총 200부의 설문지만 최종 분석에 사용하였다. 가설검증 결과, 첫째 긍정심리자본 중 자기효능감 및 희망이 업무 스트레스를 낮추는 데 영향을 끼친 것으로 나타났다. 둘째, 긍정심리자본 중 희망 및 낙관성이 학부모 스트레스를 낮추는 데 영향을 주는 것으로 나타났다. 셋째, 업무스트레스는 이직의도에는 긍정적이나 충성도에는 부정적인 영향을 끼친 것으로 나타났다. 반면 학부모 스트레스는 이직의도 및 충성도에 모두 긍정적인 끼친 것으로 나타났다. 본 연구의 결과를 바탕으로 코로나 19의 상황 속에서 유아교사의 이직의도를 낮추는 데 도움을 주는 정책 기초자료로 활용될 수 있으리라 본다.

• 대한불안의학회지
• /
• 제5권2호
• /
• pp.75-79
• /
• 2009

In this article, we review the efficacy of early interventions after traumatic incidents and during acute stress disorder (ASD). There are some evidences that psychopharmacological medications such as propronolol, morphine, and hydrocortisone are effective in the prevention of posttraumatic stress disorder (PTSD). Considering the role of selective serotonin reuptake inhibitors in hippocampal neurogenesis and an animal model of PTSD, early administration of selective serotonin reuptake inhibitors is also fairly promising. Other pharmacological treatments including benzodiazepines did not treat ASD nor prevent PTSD. There are good evidences that cognitive behavioral therapy including cognitive therapy and prolonged exposure is a valuable intervention for ASD and the most effective prevention for PTSD. No contolled researches on eye movement desensitization&reprocessing, psychodynamic psychotherapy and hypnotherapy have performed. Recent randomized controlled studies using psychological debriefing did not prove as a useful intervention for the prevention of PTSD until now, although the efficacy of debriefing has been at the centre of controversy.

• 보건교육건강증진학회지
• /
• 제31권1호
• /
• pp.27-43
• /
• 2014

Objectives: The purpose of this study was to evaluate depression of mothers with children in early childhood and to identify predictors by income level. Methods: The research was conducted with 1,761 data from the 3rd wave of the Panel Study of Korean Children(PSKC) data. Independent variables were socio-demographic data, self-esteem, normative life-events, non-normative life events, parenting stress, marital conflict, social support. Data were analyzed by t-test, ANOVA, hierarchical multiple regression analysis were conducted. Results: Significant factors of depression of female in low-income were non-normative life events, parenting stress, marital conflict. In middle class, significant factors were education, birth order of children, self-esteem, normative and non-normative life events, parenting stress, marital conflict, sociable support. At last, we found that marital conflict was the biggest factor for depression of female in low-income and parenting stress was the most powerful predictor in middle class. Conclusions: Mother's depression has a enormous impacts on development of children in early childhood. Therefore It is required to prevent depression in mothers and it is important to intervene at the early stage of depression. Results of this study showed a different pattern of predictors by income level. Therefore, Intervention and services for a mother's depression should change the direction depending on the level of income.

• Journal of Preventive Medicine and Public Health
• /
• 제49권5호
• /
• pp.253-259
• /
• 2016

Objectives: Central obesity plays a major role in the development of many chronic diseases, including cardiovascular disease and cancer. Chronic stress may be involved in the pathophysiology of central obesity. Although several large-scale genome-wide association studies have reported susceptibility genes for central adiposity, the effects of interactions between genes and psychosocial stress on central adiposity have rarely been examined. A recent study focusing on Caucasians discovered the novel gene early B-cell factor 1 (EBF1), which was associated with central obesity-related traits via interactions with stress levels. We aimed to evaluate EBF1 gene-by-stress interaction effects on central adiposity traits, including visceral adipose tissue (VAT), in Korean adults. Methods: A total of 1467 Korean adults were included in this study. We selected 22 single-nucleotide polymorphisms (SNPs) in the EBF1 gene and analyzed their interactions with stress on central adiposity using additive, dominant, and recessive genetic modeling. Results: The four SNPs that had strong linkage disequilibrium relationships (rs10061900, rs10070743, rs4704967, and rs10056564) demonstrated significant interactions with the waist-hip ratio in the dominant model ($p_{int}$<0.007). In addition, two other SNPs (rs6556377 and rs13180086) were associated with VAT by interactions with stress levels, especially in the recessive genetic model ($p_{int}$<0.007). As stress levels increased, the mean values of central adiposity traits according to SNP genotypes exhibited gradual but significant changes (p<0.05). Conclusions: These results suggest that the common genetic variants for EBF1 are associated with central adiposity through interactions with stress levels, emphasizing the importance of managing stress in the prevention of central obesity.

• 대한원격탐사학회지
• /
• 제38권6_1호
• /
• pp.1573-1579
• /
• 2022

기후변화에 따른 우리나라의 빈번한 가뭄에 따라 작물 생산량은 보존하면서 수자원 관리를 극대화하는 방법으로 작물 가뭄스트레스를 조기 탐지하여 적기에 적량이 관수되는 방식이 최근 주목받고 있다. 하지만, 대부분의 선행연구들은 가뭄스트레스가 상당히 진행되어 표징이 뚜렷한 시기에 실험되고 있어 가뭄 스트레스 초기에 원격탐지 될 수 있는 생리적 특징이 많이 알려지지 않았다. 본 연구에서는 콩을 대상으로 초기 수분 스트레스 시기에 열화상 카메라와 초분광 카메라 촬영을 수행하였다. 스트레스 우세 시기 작물 대상의 선행연구들 결과와 마찬가지로 엽온은 높아졌으며, 엽록소 함량을 대표하는 MERIS Terrestrial Chlorophyll Index (MTCI)는 감소하였다. 하지만, 오히려 광합성 능력을 나타내는 Chlorophyll/Carotenoid Index (CCI)가 증가하는 경향이 나타났다. 이는 스트레스 우세 상태와 마찬가지로 가뭄스트레스 초기에도 엽록소와 카로티노이드(carotenoid) 감소가 동시에 일어났지만, 처음의 카로티노이드 감소 속도가 엽록소에 비해 컸기 때문에 일시적으로 엽록소에 대한 카로티노이드 비율이 낮아져서 CCI가 높아진 것으로 사료된다. 이러한 스트레스 초기 반응은 조기탐지 알고리즘 개발에 유용할 것으로 기대한다.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2002년도 가을 학술발표회 논문집
• /
• pp.809-814
• /
• 2002

Recently, the properties of early-age concrete are increasingly important because these properties directly influence the behavior of early-age concrete structures including stress and cracking behavior. Nevertheless, the studies on early-age concrete are limited to strength and temperature development. The purpose of present study is to propose a simple and rational method which can predict the stress and strain behavior of young age concrete. A series of test have been done to measure the temperature development, strains and stresses in concrete members. The concept of equivalent age was used to define the degree of hydration and this degree of hydration was used to calculate the strength and elastic modulus. The critical degree of hydration and thermal expansion coefficient were calculated using experimental data. It is seen that the critical degree of hydration range from 0.05 to 0.11 based on the measuring method. The thermal expansion coefficient was calculated based on the measured non-mechanical strain and it is found that the coefficient decreases slightly with the increase of age. The consideration of critical degree of hydration in calculating stresses gives more accurate results. The present study provides useful method and data in evaluating early-age behavior of concrete structure.

• International Journal of Concrete Structures and Materials
• /
• 제18권3E호
• /
• pp.191-198
• /
• 2006

The objective of this study is to examine fracture characteristics of concrete at early ages, i.g. critical stress intensity factor, critical crack-tip opening displacement, fracture energy, and bilinear softening curve based on the concepts of effective-elastic crack model and cohesive crack model. A wedge splitting test for Mode I was performed on cubic wedge specimens with a notch at the edge. By experimenting with various strengths and ages, load-crack mouth opening curves were obtained, and the results were analyzed by linear elastic fracture mechanics and FEM(finite element method). The results from the test and analysis showed that critical stress intensity factor and facture energy increased while critical crack-tip opening displacement decreased with concrete aging from 1 day to 28 days. Four parameters of bilinear softening curve from 1 day to 28 days were obtained from a numerical analysis. The obtained fracture parameters and bilinear softening curves at early ages from this study are to be used as a fracture criterion and an input data for the finite element analysis of concrete at early ages.