• Journal of Electrical Engineering and information Science
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• v.3 no.3
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• pp.322-329
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• 1998

Stability analysis of nonlinear systems is mostly based on the Lyapunov stability theory. The well-known Lyapunov function method provides precise and rigorous theoretical backgrounds. However, the conventional approach to direct stability analysis has been performed without taking account of damping effects, which is pointed as a minor but crucial drawback. For accurate has been performed without taking account of damping effects, which is pointed as a minor but crucial drawback. For accurate stability analysis of nonlinear systems, it is required to take the damping effects into account. This paper presents a new method to derive a group of Lyapunov functions to reflect the damping effects by considering the integral relationships of the system governing equations. A systematical approach is developed to convert a part of damping loss into some appropriate system energy terms. Examples show that the proposed method remarkably improves the estimation of the region of attraction compared considering damping effects. The proposed method can be utilized as a useful tol to determine the region of attraction.

• Korean Journal of Soil Science and Fertilizer
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• v.9 no.1
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• pp.57-63
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• 1976

The lecturer pointed the agriculture in change brought about population bomb and economic development, and he appealed the scientists of soil and fertilizer to make proposals for establishing their constructive attitudes toward the situations of agriculture. The points emphasised by the lecturer for the improvement of future food situation were: fox example the elucidation of the ancient agricultural technology of Korea which is a important attempt for development of agricultural technology of Korea and Japan, and soil improvement with special attention to the efficiencies of phosphate, silicate, cations and trace elements. He showed some Japanese examples of natural pollution as both of a sufferer and an assailant of agriculture which are resulted from the high economic development, and some methods of solution, for example active application of legumes capable for fixing atmospheric nitrogen to wasted soils. He also pointed the need of lower consumption of energy and resources, and new understanding of wild plant species for the future agriculture. Some methods of other fields of sciences were emphasised for developing the soil and fertilizer researches.

• Journal of Ocean Engineering and Technology
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• v.36 no.4
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• pp.270-279
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• 2022

In this study, numerical analysis and experiments were performed to analyze the viscous damping effect according to the shape of the chamber skirt of the breakwater-linked inclined oscillating water column wave energy converter. Experiments were conducted using a two-dimensional mini wave tank and verified by comparing the results of a computational fluid dynamics numerical analysis. Pointed and rounded skirts were modeled to compare the effect of viscous damping when incident waves enter the chamber, and the difference in the displacement of the water surface in the chamber was compared according to the wave period for the two skirt shapes. The wave elevation in the chamber in the rounded-skirt condition was larger than the pointed-skirt condition in all wave periods, which was approximately 47% greater at 0.9 s of the incident wave period. Therefore, extracting the maximum energy through the optimal orifice is possible while minimizing the energy attenuation in the rounded-skirt condition.

• SUVANNABHUMI
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• v.5 no.1
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• pp.1-23
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• 2013

This study reexamines a covert factor of the colonization of Myanmar kingdom, drawing on the case of Myingyun-MyingonDaing Rebellion broke out in 1866. It criticizes that existing discussions on the downfall of the Konbaung dynasty are preoccupied with post-colonialism. These researches were focus on macro level and pointed out the imperialist stratagem and many scholars concluded for the down fall of Konbaung Dynasty that the wave of Imperialism as Sunami hit from Europe to Asia so that Myanmar could not stand as feudal society and down fall Konbaung Dynasty. All of events and comments were quite true but it is necessary to examine carefully past events. There were many controversial facts about third Anglo-Myanmar war. This paper has pointed out the Kings Mindon's false political strategic due to the lack of awareness on external threat with the giving the best example of Myingun-MyingonDaing rebellion.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.3 no.1
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• pp.127-135
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• 1999

An inequality of Ostrowski's type for monotonous nondecreasing mappings is given. Applications for quadrature formulas are pointed out.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.2
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• pp.327-333
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• 2009

In 2004, Das et al. proposed a scheme for preserving a user anonymity. However, In 2005, Chien and Chen pointed out that Das et al. scheme fail to protect the user anonymity, and proposed a new scheme. And then in 2007, Hu et al. pointed out that Chien and Chen scheme also has some problems; it is Strong masquerading server/user attack, Restricted replay attack, Denial of service attack. it also slow wrong password detection, and proposed a new scheme. In 2008, Bindu et al. repeatedly pointed out on Chien and Chen scheme and proposed their scheme. However, we point out that all of their scheme also has some problems; it is not to protect the user anonymity and Denial of service attack. In addition, Bindu et al. is vulnerable to Strong masquerading server/user attack. Therefore, we demonstrate that their scheme also have some problems; it is the user anonymity and denial of service attack as above.

• Journal of Animal Science and Technology
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• v.64 no.2
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• pp.365-379
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• 2022

The present study was conducted with the aim of investigating the effect of storage length, turning frequency and egg position on internal quality traits of chukar eggs obtained from 56-week-old chukar partridges under the same nutrition and management conditions. A total of 720 eggs were collected and assigned to 36 subgroups according to storage length (7, 14, 21, and 28 d), turning frequency (0, 1, and 24 per day) and egg position (pointed end up, blunt end up and horizontal). As a result of the study, almost all the internal quality traits of chukar eggs were negatively affected by lengthening of storage period especially 21 days and longer (p < 0.001). Internal egg quality traits weren't statistically affected by turning frequency except yolk index (p < 0.01). An improvement was observed in Haugh unit, albumen index and heigh of eggs stored with pointed end up (p < 0.001). Some significant interactions occurred among all internal egg quality traits which were mostly dependent on the eggs stored horizontally, extended storage time more than 21 days and egg turning during storage. The results and interactions showed that internal quality traits would be preserved well for the eggs stored less than 21 days with the position of pointed end up independent of turning. If the storage period was to exceed 21 days, the eggs should be positioned horizontally and turning should be applied to preserve the quality of chukar eggs.

• Journal of Korea Port Economic Association
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• v.39 no.4
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• pp.97-106
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• 2023

Most scholars and media viewed the cause of the bankruptcy of Hanjin Shipping, which once boasted the world's seventh largest company, as management failure or CEO risk. However, in this study, the cause of Hanjin Shipping's bankruptcy was considered to be the collective action of ship investment from a behavioral economics perspective, and it was pointed out that the Korean government's inflexible fleet expansion policy was the background for this collective action. In short, the cause of Hanjin Shipping's bankruptcy was the purchase of ships during the boom period, and the root cause of the purchase of ships during the boom period was pointed out as 'collective action in which one feels safe only by following the actions of others.' In addition, in order to achieve the goal of 'shipping competitiveness = fleet size' set by our government, a policy was implemented to encourage ship purchases during recessions and even boom times, and this policy signaled to the market that 'now is a good time to buy ships'. It can be pointed out that was given.

• International Journal of Costume and Fashion
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• v.11 no.1
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• pp.63-83
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• 2011

This study aims to prove the changes, development and social background of Korean male cosmetics over the period of 2000-2010. There were total 574 articles written about male make-up and cosmetics in Chosun Daily, Joongang Daily and Donga Daily, which are the top three Korean local daily newspapers in terms of sales revenue for that period. These articles were analyzed together with social background research from various books and daily newspapers. The analysis of articles was divided into different categories; such as foundation cosmetics, color cosmetics, hair, and the social background. It was found that the articles related to foundation cosmetics were written the most, the articles related to male appearance management were second, articles on other items including how to manage the skin being the least. As for the social background of Korean male cosmetics, first of all, a change in social recognition can be pointed out. The traditional understanding of gender roles has changed, men's appearance management has started to be regarded as a competitive talent, and at the same time, the esthetic viewpoint for men also has changed. One example is the newly made popular term, "flower-handsome man", which shows the new trend of favoring males with nice skin. Second, the expansion of mass culture can be pointed out. As consumers can get information and fashion trends easier and faster, the fashion spreads fast, and this has led to the generalization and popularization of the sense of beauty. Third, the development of scientific technology and medical science can be pointed out. Thanks to the progress in those areas. the extension of youthfulness has become possible and the cosmetics industry was also affected greatly, as shown in the market spread of functional products for anti-ageing and wrinkle control as the interest in anti-ageing has grown. There are benefits from the development of scientific technology, but the problem of environmental pollution has appeared due to machinery and industrialization and thus the issue of well-being has been raised. Rising interest in naturalism, pro-environmentalism and organic cosmetics has influenced the cosmetics industry. In addition, the quantity of ultraviolet rays exposed to our skin has increased due to the air pollution caused by the destruction of environment, leading to increased usage of sun block lotion. Lastly, the influence of consumer society and the expansion of consumerism culture can be pointed out. In the modern society, consumption acts not only as the use of products and services but it also has an important role of mediating individuals with others and the society. The market for male cosmetics has been expanding and the number of men putting on make-up has been increasing rapidly. Therefore, this study is meaningful in that the analysis of the mode of change and the social background are an essential process in order to provide a direction for the future market for male cosmetics.

• Korean Journal of Cognitive Science
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• v.29 no.1
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• pp.17-38
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• 2018

The purpose of present study was to examine whether the perceived distance is compressed to different extent according to the length of the tool in the object that is not reachable even when using the tool, and whether the perceived distance is compressed according to the tool length only in the object being pointed. In Experiment 1, we found by measuring the egocentric distance that the length of the tool causes the distance to the target to be closer to that of the object placed at a far distance. In Experiment 2, we found by measuring the egocentric distance that when the operated object and the non-operated object coexisted in the visual field, the length of the tool does not affect the distance perception to the non-pointed object. In Experiment 3, we found that the tool length affects only the distance perception of the operated object by measuring the exocentric distance which is the distance between the operated object and the target in the same environment as Experiment 2. The results of present experiment suggest that the compression of the perceived distance occurs at a distance that can not be reached by using the tool, and that the compression of the perceived distance is limited to the pointed object.