• Korea journal of population studies
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• v.24 no.2
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• pp.47-78
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• 2001

The primary purpose of this paper is to critically examine the theoretical and methodological issues in the study of generations. The issues include: 1) the concept of generation: 2) the basis of generational formation: 3) internal differentiation of generations: 4) the boundary problems of generations: 4) the boundary problems of generations: and 5) generational differences and generational conflict. From the investigation of these issues, two conclusions are drawn. Firstly, Mannheim's basic concepts and theoretical frameworks are very useful to understand and explain the social movements and sociocultural changes. Secondly, however, further elaboration and modification of the several concepts and frameworks are needed to deal with the problems of generations in general which are not directly connected to social movements. Several points are suggested to elaborate Mannheim's frameworks, which include the reconceptualization of generation, and introducing the concepts of “generation sects” and “manifest-latent generational conflicts”.

• Journal of computational fluids engineering
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• v.20 no.4
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• pp.70-80
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• 2015

Construction waste is known to include a large part of coarse and fine aggregates, which can be recirculated in the industry. Separating those aggregates economically from the waste has been thus considered to be one of the most important issues in this field. In particular, paste mixed in the waste causes significant complain from the inhabitants living near the place where waste-processing equipments are built and operated. In this study, we investigate the operational principle of a newly developed paste separator by using theoretical (in this first part) and CFD (in the second part) analysis. The separator consists of a rotor which turned out to play a significant role in separating those pastes from the aggregates. Under suitable assumptions regarding the air flow velocity as well as the particle velocity, we show that particles can be stagnant at the outlet of the roto channel for a wide range of parameter values, which allow the particles to get enough time to settle down via the gravitation. We also demonstrate such phenomenon by using a simple numerical simulation.

• Journal of the Korean Geographical Society
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• v.40 no.3 s.108
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• pp.335-352
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• 2005

The question of whether fan type surface developed at the foot of mountains is pediment or alluvial fan has been discussed consistently through the Korean geomorphic history. Unfortunately the term, 'alluvial fan' was scarcely used, also even the existence of alluvial fan has been denied throughly for a long time in Korea. The negation of alluvial fan brought some difficulties in the development of the related Geomorphology. In order to resolve such a problem, more logical and exquisite theory by examination of geomorphic process must be systematically presented on the basis of overall problem recognition. The objective of this study is to represent the theoretical indicator based on the investigation of the points at issue that the existence of alluvial fan in Korea was denied. Moreover, we selected 13 alluvial fans in southern part of Korean Peninsula to compare with the worldwide alluvial fans according to theoretical indicator, and analysed their geomorphic distributional characteristics.

• 대한공업교육학회지
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• v.31 no.1
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• pp.185-199
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• 2006

In this paper, to detect lateral direction sound pressure fiber optic sensor using Fabry-Perot interferometeric sensor array was fabricated and experimented. This parallel sensor array composed of one light source and the light split into each sensor using directional coupler and to see the output signal the array system do not need any digital signal processor. As a lateral direction sound source arbitrary sound frequency of 100Hz, 200Hz, and 655Hz using by nondirectional speaker were applied to the array sensor which installed on $60cm{\times}60cm{\times}60cm$ latticed structure. The detected signals from the two sensors were analyzed in the time and frequency domains. It was confirmed that the suggested sensor array detected applied sound source well but there were a little amplitude differences in between the sensors. Because the sensor supported simply at both ends theoretical analysis was performed and its solution was suggested. To compare the theoretical and experimental results arbitrary sound frequency of 2kHz was applied to the sensor array. It shows that experimental results was good agreement with theoretical results.

• Journal of Korea Technology Innovation Society
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• v.20 no.4
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• pp.888-914
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• 2017

The main aim of this study is a meta-theoretical investigation to explain the current theoretical landscape of social innovation theories and researches. First of all, this paper makes a typology of social innovation based on concepts and sectors of social innovation. Second, in terms of societal innovation, which it is a kind of social innovation systematic approach, this paper draws some implications for social innovation policy. My key argument is that social innovation could be specified in three different sectors, public innovation, market innovation, and social economy innovation. However, all of them have attention to such as improving a quality of life and making society more sustainable, so it can be argued that those different sectors are structured on social innovation altogether with common goals. Finally, in order to activate the social innovation ecosystem, the government has to play a key role as a facilitator to make sustainable networks and a governance of social innovation that is needed to coordinate between different features and roles of social innovation sectors.

• Journal of Animal Science and Technology
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• v.60 no.2
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• pp.3.1-3.9
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• 2018

Background: Poultry breeding has increased by 306% in Korea, inevitably increasing the production of manure which may contribute to environmental pollution. The nutrients (NP) in the manure are essential for crop cultivation and soil fertility when applied as compost. Excess nutrients from manure can be accumulated on the land and can lead to eutrophication. Therefore, a nutrient load on the finite land should be calculated. Methods: This study calculates the nutrient production from Korean poultry by investigating 11 broiler and 16 laying hen farms. The broiler manure was composted using deep litter composting while for layer deep litter composting, drying, and simple static pile were in practice. The effect of weight reduction and storing period during composting was checked. Three weight reduction cases of compost were constructed to calculate nutrient loading coefficients (NLCs) using data from; i) farm investigation, ii) theoretical P changes (${\Delta}P=0$), and iii) dry basis. Results: During farm investigation of broiler and layer with deep litter composting, there was a 68 and 21% N loss whereas 77 and 33% P loss was found, respectively. In case of layer composting, a loss of 10-56% N and a 52% P loss was observed. Drying manure increased the P concentrations therefore NLCs calculated using dry basis that showed quite higher reductions (67% N; 53% P). Nutrient loss from farm investigation was much higher than reported by Korean Ministry of Environment (ME). Conclusions: Nutrients in manure are decreased when undergo storing or composting process due to microbial action, drying, and leaching. The nutrient load applied to soil is less than the fresh manure, hence the livestock manure management and conservation of environment would be facilitated.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.3
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• pp.2234-2241
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• 2015

This study has been undertaken to develop a relationship between the shear strength coefficients and the cone index. The theoretic mathematical equations for the relationship were rigorously investigated, and then a Artificial Neural Network(ANN) analysis was adapted to enhance the reliability of the investigation. The theoretical investigation involved various assumptions resulting in the significant error involvement of geotechnical behaviors of ground. Therefore, a model using the ANN has been learned to enhance the prediction of the cone index form the shear strength parameters. Site investigation reports from various construction fields were used for ANN model learning. The results of the study show that the model predicts the cone index from the shear strength parameters of soils very well. The further study that is undertaking has a potential promise of the generalized prediction technique for the cone index from the soil parameters.

• Transactions of the KSME C: Technology and Education
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• v.2 no.1
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• pp.15-20
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• 2014

Intuitive learning method was applied at the beginning of each lecture to induce students to draw their interests. Avoiding simple explanation of equations and problem solving by using them, we repeated theoretical concepts verbally and applied physical meanings when we developed and wrote equations. By these methods we expected to find a way to increase students' learning effects. We also took a group investigation on pursuing term projects. Students choose their own subjects individually and submitted reports according to the time schedule. The reports included the contents that they learned during classes. After choosing best reports for each group by instructor, students at each group divided roles and prepared presentations. Thorough these methods they increased their scores from mid-term to final exams, and got aquatinted with responsibilities among group and organizations. They also experienced physical meanings from the usual daily life phenomena which could be connected to the engineering concepts and improved abilities as junior engineers.

• Journal of The Korean Association For Science Education
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• v.39 no.1
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• pp.101-113
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• 2019

This study aims to explore which aspects of student agency have previously been studied and the ways agent practices have been investigated in learning communities in research on science education. Results reveal five aspects of agency related to students' actions in a learning community: epistemic agency, transformative agency, educated action in science, disciplinary agency, and material agency. We delineated how agency is captured in epistemic practices, as described in the literature on each of the aforementioned aspects. We also probed into the three approaches by which previous research has examined the practices of students as agents that construct learning communities. These approaches are (a) the investigation of students' actions as representative of the agency of an entire learning community, (b) the exploration of the effects of focused student action on the structure of activity, and (c) the investigation of interactions between students as agents. We discussed the implications of previous research on the basis of each approach to understanding the diverse features of student-centered learning communities. The present work contributes to the exploration and support of students' practices as agents in the learning communities in science classrooms.

• Journal of the Korean Society of Safety
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• v.37 no.6
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• pp.136-147
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• 2022

The purpose of this study is to analyze four cases of firefighter burns in various fire scenes and to find prevention measures to decrease firefighter injuries. Among the analysis reports prepared by the National Fire Research Institute of Korea from 2016 to 2020, four burn-related accidents are summarized and the main causes are conveyed. The four accidents include second-degree burns from using extinguishers during containment of fires; nine firefighters burned due to re-ignition in the LPG car repair shop; two firefighters injured with third-degree burns from using fire extinguishers during life-saving events in residential housing; and injuries from the radiant heat of the tank BLEVE near the factory fire. These cases are comprehensively investigated in their respective scenes and analyzed based on the fire site investigation reports from the fire department and related theoretical explanations of risk for each accident scene. In the third case study, some experimental research is conducted to evaluate the risk involved with the use of safety gloves. This is evaluated by reviewing Fire Tactics and Standard Operational Procedures (SOP) to determine improvements and recommendations for an efficient firefighting response. Results show that the main causes of burn accidents are the insufficient use of personal protective equipment (PPE), such as safety gloves, and the failure to follow firefighting tactics or SOPs. Through the accident investigation and assessment, it is concluded that to reduce the frequency of burn accidents, the performance of firefighting equipment, SOPs, protection tactics, and safety policy systems require improvement.