• Computers and Concrete
• /
• v.24 no.4
• /
• pp.347-367
• /
• 2019

This work investigates the effect of Winkler/Pasternak/Kerr foundation and porosity on dynamic behavior of FG plates using a simple quasi-3D hyperbolic theory. Four different patterns of porosity variations are considered in this study. The used quasi-3D hyperbolic theory is simple and easy to apply because it considers only four-unknown variables to determine the four coupled vibration responses (axial-shear-flexion-stretching). A detailed parametric study is established to evaluate the influences of gradient index, porosity parameter, stiffness of foundation parameters, mode numbers, and geometry on the natural frequencies of imperfect FG plates.

• Steel and Composite Structures
• /
• v.38 no.1
• /
• pp.1-15
• /
• 2021

In this paper, a higher order shear deformation theory for bending analysis of functionally graded plates resting on Pasternak foundation and under various boundary conditions is exposed. The proposed theory is based on the assumption that porosities can be produced within functionally graded plate which may lead to decline in strength of materials. In this research a novel distribution of porosity according to the thickness of FG plate are supposing. Governing equations of the present theory are derived by employing the virtual work principle, and the closed-form solutions of functionally graded plates have been obtained using Navier solution. Numerical results for deflections and stresses of several types of boundary conditions are presented. The exactitude of the present study is confirmed by comparing the obtained results with those available in the literature. The effects of porosity parameter, slenderness ratio, foundation parameters, power law index and boundary condition types on the deflections and stresses are presented.

• Journal of muscle and joint health
• /
• v.21 no.2
• /
• pp.135-144
• /
• 2014

Purpose: The purpose of this study was to analyze and clarify the concept of shift work maladaptation syndrome and to facilitate development of interventions for the shift work adaptation. Methods: This study used Walker and Avant's concept analysis process. Results: Shift work maladaptation syndrome can be defined as the following attributes: 1) destruction of the circadian rhythm, 2) existence of a threshold, 3) individual characteristics (year of career, type of personality, and type of coping) 4) somatization, and 5) negative emotional conditions. The antecedents of shift work maladaptation syndrome consist of counterclockwise shift work, irregular shift cycle, night work which is breaking circadian rhythm, and lifestyle changing. The consequences as a result of shift work maladaptation syndrome are deterioration of health (gastrointestinal, neuro-psychic, cardiovascular function), reduction of social relationships, and turnover or resign. Conclusion: The results of this study can be useful as the foundation of shift work adaptation implementation.

• Fisheries and Aquatic Sciences
• /
• v.12 no.1
• /
• pp.29-34
• /
• 2009

Fifty seven species of common seaweed from the coast of Korea were screened for antifungal activity against Malassezia species. Seaweeds as a source of bioactive compounds are able to produce a great variety of secondary metabolites with different activities. There are numerous reports on the biological activities of seaweeds against human pathogens, fungi, and yeasts, but only few contain data regarding inhibitory effects against Malassezia sp., a major cause of dandruff and seborrheic dermatitis. To help address this paucity of information, this work was carried out to examine the antifungal effects of seaweed extracts against M. furfur and M. restricta. Of the fifty seven species of marine algae screened for their potential antifungal activity, only 17 species (29.8%) exhibited inhibitory activity. In agar disc diffusion method, the ether extracts of Corallina pilulifera, Enteromorpha linza, Laminaria japonica, Symphyocladia latiuscula and Ulva sp. showed strong antifungal activity. To identify major constituents in seaweed extracts, four selected extracts were analyzed on' a GC-MS equipped with a flame ionization detector, and compared to spectral data from databases WILEY229.LIB and NIST107.LIB. Most constituents in seaweed extracts are fatty acid-related compounds. When we evaluated any acute toxicity, the ether extracts of the selected four species were not toxic in mice. According to these results, it can be suggested that these seaweed extracts are valuable for the development of therapeutic agents in treating dandruff and seborrheic dermatitis. Further investigations to determine its bioactive compound(s) are currently in progress.

• Journal of Korean society of Dental Hygiene
• /
• v.19 no.6
• /
• pp.907-918
• /
• 2019

Objectives: This qualitative research was conducted to clearly find and clinically understand dental hygienists' work experience in order to lay the legal foundation for their work range and safe execution. Methods: From March 1 to April 30, 2019, seven study participants were selected and participated in-depth interviews. Phenomenological research methodology was applied for intensive analysis. Results: They performed jobs that required no professionalism, such as dental assistance, except for scaling. Dental hygienists, nurses' aids, and dental technicians performed the same jobs regardless of difficulty level and legal work range. Dental hygienists failed to accurately recognize their legal work range. Since there was the wide gap between their legal work range and actual work range, it was necessary to expand the work range in line with actual conditions. Conclusions: Given the results, it is necessary to conduct in-depth discussions within the dental circle to make dental hygienists' work execution in line with reality by improving and discussing a legal system for job assignment and expansion of workers. Therefore, it is required to form a plan for the many jobs dental hygienists executed in a clinical setting.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1996.04a
• /
• pp.827-831
• /
• 1996

In this work, we propose the algorithm of similarities and design parameters by which can have a design model cmploying the analogical inference analogy. The physical characteristics for the instrument model forms the foundation of the proposed method and are brought to researchers and designers which build the systematizatio design using a computer.

• Magazine of the Korea Concrete Institute
• /
• v.26 no.1
• /
• pp.46-50
• /
• 2014

• Proceedings of the Korea Water Resources Association Conference
• /
• 2001.05b
• /
• pp.727-732
• /
• 2001

Abstract, See Full-text

• Journal of the Korea Institute of Building Construction
• /
• v.10 no.4
• /
• pp.83-93
• /
• 2010

With construction projects continuously becoming more massive and complex, risk factors have been consistently increasing. To achieve a successful project, it is very important to identify and cope with such risk factors. Therefore, the purpose of this study is to suggest plans of reducing risk, not only for describing the drafting process for construction planning but also for systematically organizing constraints and risk factors in earth work, foundation work and reinforced concrete construction. To achieve these objectives, this study 1) analyzes previous theories about risk classification structure, 2) performs a case study of an actual project to embody the problems of safety management by analyzing the results of an interview with a construction engineer. In conclusion, the following factors were systematically organized: 1) characteristics of construction site (purpose, structure, floor, etc.); 2) the actual application conditions of the main construction methods; 3) the relationship between constraints and risk factors.

• Journal of KIBIM
• /
• v.12 no.4
• /
• pp.80-92
• /
• 2022

Recently, remote work has arisen due to the social atmosphere and advancement of digital technology. Although effective in premeditated communications such as conferences or meetings, the current technology such as messengers and video chats insufficiently supports impromptu communications like a chance encounter, daily conversation with colleagues, or brief instant meetings. This causes various problems such as a decrease in social belonging and an increase in social isolation. The virtual workplace, which emerged as an alternative to this technology, is merely replicating the workplace layouts in reality with an absence of the proper design guideline. Therefore, this paper aims to establish the foundation for the better design of the virtual workplace for remote-work employees. The research compared 12 current workplace cases with the analysis with 5 categories(Spatial Composition, Scale, Individual & Collaboration Workplace, Socializing Space), and discovered the following results: 1) some design principles of the real workplace can be applied on the virtual workplace design, 2) the architectural components of the virtual workplace can differ from them of the real. Based on the results, the research suggests both the appropriate design methodologies of the virtual workplace considering the design principles of the real office layouts, and the design direction for the future of the virtual workplace. This research will be the foundation for the future design of the virtual workplace.