• 대한수학회보
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• 제50권4호
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• pp.1099-1108
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• 2013

We define the Mannheim curve in a 3-dimensional Riemannian manifold, which is a generalization of the Mannheim curve in Euclidean space. In particular, we study the Mannheim curves and their partner curves in 3-dimensional space forms.

• 호남수학학술지
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• 제44권3호
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• pp.419-431
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• 2022

Mannheim introduced the concept of a pair of curves, called as Mannheim partner curves, in 1878. Until now, Mannheim partner curves have been studied widely in the literature. In this study, we take into account of this concept according to Positional Adapted Frame (PAF) for the particles moving in the 3-dimensional Euclidean space. We introduce a new type special trajectory pairs which are called Mannheim partner P-trajectories in the Euclidean 3-space. The relationships between the PAF elements of this pair are investigated. Also, the relations between the Serret-Frenet basis vectors of Mannheim partner P-trajectories are given. Afterwards, we obtain the necessary conditions for one of these trajectories to be an osculating curve and for other to be a rectifying curve. Moreover, we provide an example including an illustrative figure.

• Journal of Preventive Medicine and Public Health
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• 제52권3호
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• pp.161-169
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• 2019

Objectives: The objective of the present study was to validate a shortened transformational leadership (TL) scale (12 items) comprising core TL behaviour and to test the associations of this shortened TL scale with depressive symptoms. Methods: The study used cross-sectional data from 1632 employees of the overall workforce of a middle-sized German company (51.6% men; mean age, 41.35 years; standard deviation, 9.4 years). TL was assessed with the German version of the Transformational Leadership Inventory and depressive symptoms with the Hospital Anxiety and Depression Scale (HADS). The structural validity of the core TL scale was assessed with confirmatory factor analysis. Associations with depressive symptoms were estimated with structural equation modelling and adjusted logistic regression. Results: Confirmatory factor analysis and structural equation modelling showed better model fit for the core TL than for the full TL score. Logistic regression revealed 3.61-fold (95% confidence interval [CI], 2.20 to 5.93: women) to 4.46-fold (95% CI, 2.86 to 6.95: men) increased odds of reporting depressive symptoms (HADS score >8) for those in the lowest tertile of reported core TL. Conclusions: The shortened core TL seems to be a valid instrument for research and training purposes in the context of TL and depressive symptoms in employees. Of particular note, men reporting poor TL were more likely to report depressive symptoms.

• Safety and Health at Work
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• 제13권2호
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• pp.213-219
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• 2022

Objective: The Job Demand & Resources model suggests work characteristics are related to mental well-being and work engagement. Previous work describes the development of a combined construct 'engaged well-being at work' (EWB). To what extent changes in measures of this construct are responsive to changes in job demands and resources or associated with changes in job-related attitudes has not been established. Methods: Longitudinal employee-level data from three waves (German Linked Personnel Panel) were used. Logistic and linear fixed effects regression analyses explored longitudinal associations between changes in EWB for participants over a three-year period with changes in job demands and resources and job-related attitudes (job commitment, satisfaction, and turnover intentions). Results: While job resources were associated with increased odds for a change into a healthier and/or more engaged category of EWB, job demands reduced them. Job resources were more strongly related to higher EWB (OR_range = 1.22 - 1.61) than job demands (OR_range = 0.79 - 0.96). Especially psychological job demands showed negative associations with improved EWB (OR = 0.79). A change from the least desirable category 'disengaged strain' to any other category of EWB was associated with greater odds by up to 20.6 % for increased commitment and job satisfaction and lower odds for turnover intentions. Discussion: Improving work characteristics, especially job resources, could increase employees' EWB, emphasizing the importance of job characteristics for a healthy workplace. Because EWB seems to be associated with job attitudes, an improvement of this indicator would be relevant for employees and employers.

• 한국환경성돌연변이발암원학회:학술대회논문집
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• 한국환경성돌연변이발암원학회 2001년도 Korean Environmental Mutagen Society
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• pp.93-94
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• 2001

• 건축사
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• 3호통권53호
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• pp.54-66
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• 1973

• 한국독성학회:학술대회논문집
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• 한국독성학회 2001년도 International Symposium on Dietary and Medicinal Antimutgens and Anticarcinogens
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• pp.93-94
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• 2001

Former studies dealing with combined effects caused by chemical compounds in the metabolically competent hepatoma cell line Hep G2 indicated that Hep G2 cells are useful and sensitive indicators for the identification of synergisms of promutagens, comutagens and antimutagens which are relevant in eukryontic (human) cells. In the present study we examined the modulation of DNA damages by the suspected antimutagens ascorbic acid, beta-carotene, alpha-naphthoflavone and beta-naphthoflavone in Hep G2 cells.(omitted)

• Journal of applied mathematics & informatics
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• 제11권1_2호
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• pp.1-57
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• 2003

Vector fields in three-space admit bundles of internal variables such as a Heisenberg algebra bundle. Information transmission along field lines of vector fields is described by a wave linked to the Schrodinger representation in the realm of time-frequency analysis. The preservation of local information causes geometric optics and a quantization scheme. A natural circle bundle models quantum information visualized by holographic methods. Features of this setting are applied to magnetic resonance imaging.

• 호남수학학술지
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• 제45권3호
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• pp.380-396
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• 2023

In this study, we introduce the adjoint curves of framed curves. We examine some characterizations of adjoint curve of a framed curve. In addition, we give the conditions for framed curves and adjoint curves to be Bertrand and Mannheim curves. Then, we introduce adjoint curves of Frenet-type framed curves and give ruled surfaces related to adjoint curves. Finally, we create normal and binormal surfaces of the framed adjoint curves and obtain some characterizations of these surfaces and we support by the results with figures.

• 한국인구학
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• 제24권2호
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• pp.47-78
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• 2001

이 연구의 목적은 세대 연구의 이론적·방법론적 쟁점들을 만하임의 시각을 중심으로 하여 비판적으로 검토함에 있다. 여기에서 검토할 쟁점들은 1) 세대의 개념, 2) 세대 형성의 기반, 3) 세대의 내적 분화, 4) 세대간 경계선 설정의 문제, 5) 세대차이와 세대갈등 개념에 관련된 쟁점 등이다. 이러한 쟁점들의 검토 결과 다음과 같은 두 가지 결론을 얻게 되었다. 첫째, 세대문제에 관한 만하임의 개념과 이론이 매우 유용하고 지식사회학적인 통찰력이 돋보인다는 점이다. 둘째, 그의 이론이 사회운동을 설명하기에는 적절하지만 그와 직접적 관련이 없는 일반적인 세대문제를 다루기 위해서는 추가적인 개념과 이론화가 필요하다는 점이다. 만하임의 이론을 보완하기 위하여 이 논문에서 새로이 제시한 점은 1) 세대의 보다 일반적 수준에서의 개념화, 2) 세대내 분파 개념의 도입, 3) 세대차이·세대갈등에 대한 보다 포괄적인 개념적 이해의 필요성 제시, 4) 현재적-잠재적 세대갈등의 개념 구분 등이다.