• Journal of applied mathematics & informatics
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• v.37 no.3_4
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• pp.183-200
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• 2019

We have constructed a robust numerical method on Shishkin mesh for a class of convection diffusion type turning point problems with Robin type boundary conditions. Supremum norm is used to derive error estimates which is of order O($N^{-1}$ ln N). Theoretical results are verified by providing numerical examples.

• Journal of applied mathematics & informatics
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• v.38 no.1_2
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• pp.113-132
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• 2020

In this paper, a class of linear second order singularly perturbed delay differential turning point problems containing a small delay (or negative shift) on the reaction term and when the solution of the problem exhibits twin boundary layers are examined. A hybrid finite difference scheme on an appropriate piecewise-uniform Shishkin mesh is constructed to discretize the problem. We proved that the method is almost second order ε-uniformly convergent in the maximum norm. Numerical experiments are considered to illustrate the theoretical results.

• Journal of the Korean Mathematical Society
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• v.51 no.4
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• pp.679-702
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• 2014

Investigation of the numerical solution of singularly perturbed turning point problems dates back to late 1970s. However, due to the presence of layers, not many high order schemes could be developed to solve such problems. On the other hand, one could think of applying the convergence acceleration technique to improve the performance of existing numerical methods. However, that itself posed some challenges. To this end, we design and analyze a novel fitted operator finite difference method (FOFDM) to solve this type of problems. Then we develop a fitted mesh finite difference method (FMFDM). Our detailed convergence analysis shows that this FMFDM is robust with respect to the singular perturbation parameter. Then we investigate the effect of Richardson extrapolation on both of these methods. We observe that, the accuracy is improved in both cases whereas the rate of convergence depends on the particular scheme being used.

• Korean Journal of Applied Biomechanics
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• v.14 no.1
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• pp.117-131
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• 2004

The foreign superior players and national team players' turning phase was measured, compared and analyzed to help the representative players improve the skill of turn. The underwater video camera used to analyze and evaluate the representative players' skill of turn in detail and the result is as follows. 1. The record for the phase of turn was similar to the rank of the last record. The improvement of the skill of turn was required because Korean players' record was lower than the foreign players' one. In case of 200m events the 1st turn was the fastest and it took more time as the turn is repeated. 2. It shows that the preparation phase and turing motion cause the difference between the players and within one player. 3. The horizontal movement of center of gravity moves to turning point slowly in the preparation phase, does not move nearly in the turning phase and increase again in the propulsion phase. Good record has short time for turn phase. The result means that the shorten the turning phase is the most important factor. Therefore the preparation for this is required. The vertical movement is maintained or increase a little and then move to from the turning phase. 4. The characteristic of horizontal velocity in center of gravity is that there is any big changes at the preparation phase, the faster velocity is found from the better record and the accelerating time is fast at the propulsion phasen. The wrong motion is made by not using the swimming velocity for fuming and waiting and more time is required by this. 5. The angle of knee when the player touch the turning point is 106.22-135.56 and the maximum angle of knee during the driving after the touch of tuning point is full extension. The size of maximum angle of knee did not match with the required time of propulsion phase. It seems that the individual difference is big when the players touch the turning point the angle of knee and the research for the individual angle which can reveal the maximum power should be carried out. The national team player's skill for the him is behind the foreign players' one and a lot of problems were found. It shows that the players could not practice the skill for turn during the training. The 1st reason for it is the various facilities like underwater window or analyzing equipment like underwater camera with which the coaches can teach and correct the players' detailed skill. It is need to evaluate the players' detailed skill exactly and correct it by objective data to complete the good skill in the future. In this regard, the investment for the facility is necessary.

• IE interfaces
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• v.3 no.2
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• pp.13-22
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• 1990

The efficient and economical use of an FMS presupposes a good capability : flexibility, reliability, maintainability and built-in quality assurance. One subsystem of an FMS, which often increases capability, is the tooling management. The main problems associated with tooling in an FMS are large variety of tools, many setups, insufficient use of presetted tools, tool condition control, tool shortages, errors in tooling data and maintainence. This paper presents a reseach on the development of a system which manages the tool data for the factory using NC turning machines. The tool information concerning each production stages of the industry is studied in the CIM(Computer Integrated Manufacturing) view point.

• Journal of architectural history
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• v.5 no.2 s.10
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• pp.40-52
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• 1996

From the early 1980's, when Chinese government decided to take an Open-Policy. Chinese society faced a new turning point to be changed from traditional-society to modern-society. As a result her outstanding phenomena of civilization is to be seen in many points, like the oid styled traditional street is rapidly replaced by the modernized high-rise buildings. Like the other cities in China, Beijing(北京) also is on the step of modernization, and it's changing speed is faster time by time. In this paper, I'll discuss about Beijing's policy of reservation of Old castles(古城), some problems what they have though the procedure of China's Movement of Old Castle Reservation(古城保護運動). And through this case study, I'd like to focus on the way how we solve some problems what we have now concerning to the reservation and development of traditional cities.

• International Journal of Advanced Culture Technology
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• v.11 no.3
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• pp.83-88
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• 2023

The increasing global average temperature and the emergence of various abnormal climate phenomena are already being experienced in reality. The problems arising from climate change are expanding and becoming catastrophic, despite the efforts of various organizations to prevent them. In order to avoid climate issues from becoming black elephants, we conducted interviews with emergency planning officer from various institutions to identify potential X-events caused by climate change. The results of analyzing the anticipated X-events by these emergency planning officer revealed a chain of ripple effects associated with their occurrence. This implies that once an X-event happens, its influence is broader and more significant. Through this study, we aim to share the understanding of the ripple effects of climate X-events with many people, raising awareness of the severity of climate issues. We hope that this will serve as a starting point for more institutions, individuals, and nations to make efforts in resolving climate problems, turning X-events into opportunities rather than crises.

• Journal of the Korea Safety Management & Science
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• v.15 no.3
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• pp.19-28
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• 2013

While the reduction of industrial accidents has been stagnant, many researchers have been studying and focusing on safety behaviors including safety perception, attitude and safety culture as a new solution as well as a turning-point of this issue. However, we do not pay attention to those studies and researches in Korean construction. Therefore, this study is to introduce preceding researches and case studies in other countries and suggest a new direction to Korean construction. This study found out the current situation and problems in Korean construction studies after tracing the safety perception, attitude and safety culture in Korea and reviewing the background and trend of overseas studies and researches with regard to safety behaviors. Fundamental researches and systematic studies must be conducted in Korean construction with the reference and research data of this study.

• Journal of the Korean housing association
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• v.16 no.6
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• pp.93-100
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• 2005

Turning into the 21st century, there are great demands for the diversification of housing style and amenity of housing, which include enhancing community life through proper collective environment. To solve these problems, cohousing has been introduced in Scandinavian countries. A primary goal of cohousing is the desire of residents to live in a socially supportive setting. People can do housework together and also can promote active mutual relationship among residents in the community. Physical feature of cohousing, in combination with social organization factors, nay serve to enhance or support the sense of community sought by residents. In this point of view, the purpose of this study is to consider the characteristics of planning factors applied to the community concept in cohousing. First consideration is to figure out the planning skills on community concept in housing community. Then, by making clear the planning factors on community concept in cohousing through case study, this paper could suggest a possibility of application of cohousing in Korea.

• Korean Journal of Human Ecology
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• v.12 no.4
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• pp.529-537
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• 2003

This study was conducted to manufacture the soluble micro-fiber and to synthesize low melting polymer for the interior fabric not to use the polyurethane resin causing some problems. Low melting polyester for weft yarn was introduced by adding 30-40 mol% ratio of isophthalic acid to a main chain of polyethylene terephthalate to decrease the melting temperature up to heat setting temperature. Micro-fiber for warp yarn consisted of both soluble and insoluble components with multi-layered structure. When the soluble micro-fiber was treated by alkaline hydrolysis with 3-5% concentration of NaOH, it showed the turning point at 28% weight loss since soluble polyester was hydrolyzed approximate five times faster than regular polyester.