• Korean Journal of Mathematics
• /
• 제27권1호
• /
• pp.81-92
• /
• 2019

We introduce a reciprocal-negative Fermat's equation generalized with constants coefficients and investigate its stability in a quasi-${\beta}$-normed space.

• 한국수학교육학회지시리즈B:순수및응용수학
• /
• 제26권2호
• /
• pp.85-97
• /
• 2019

In this paper we introduce the reciprocal-negative Fermat's equation induced by the famous equation in the Fermat's Last Theorem, establish the general solution in the simplest cases and the differential solution to the equation, and investigate, then, the generalized Hyers-Ulam stability in a $quasi-{\beta}-normed$ space with both the direct estimation method and the fixed point approach.

• 가정과삶의질연구
• /
• 제27권2호
• /
• pp.173-189
• /
• 2009

The purpose of this study was to find and provide the prevention method by examining the Effects of Maternal Negative Behaviors and Children's Attachment Stability on Children's Aggression. The subjects were 339 children of fifth or sixth graders in Seoul. The questionnaires were derived and modified from Young Ae Park (1995) for the maternal negative behavior, Children's attachment stability from Ok Jung (1998) and Children's aggression from In Sun Jung(2006). The date were analyzed with descriptive statistics, t-test, F-test, Pearson's correlations and hierarchical multiple regression by SPSS 14.0 program. The major findings were as follows : First, the result showed there was average level of negative relationship when mother's negative behavior was compared with children's attachment whereas it showed average level of positive relationship in aggression. And also, low level of negative relationship showed between the attachment and aggression. Second, studying the influence it gives to the children's reaction and aggression after adding the children, parent and the family's popular social variables into the maternal's negative behavior, the outcomes showed the maternal's discipline and defiance upbringing had influenced the highest and tolerance, negligence was second high. This study mainly looked at the relationship between the maternal negative behavior with the children's attachment and aggression, but not like the nations pre.studied results, changes in human relation were examined with identifying the main several factors that bring greatest influence to the children's attachment and aggression. In conclusion, the children's attachment and aggression's the cause of the children's attachment and aggression were mainly from the maternal discipline and defiance upbringing. Based on this conclusion, it is essential for the maternal to have a sound discipline with right minds for endeavor to bring up the children with bring minds with less aggression and composed attachment.

• 한방재활의학과학회지
• /
• 제18권2호
• /
• pp.157-167
• /
• 2008

Objectives : It is sure that standardization of medical instruments is very important and necessary. Cupping therapy is one of the traditional oriental medical method, and it is necessary to set up a standard of cupping therapy and instruments. Methods : We select 3 major cupping instrument makers according to a questionnaire survey of 2001 oriental medical doctors. Dae Gun is A maker, Han Sol is B maker, Dong Bang is C maker. And with these air pumps we make experiments on stability by an inner impact test and a falling test. With these cups we check stability by an inner impact test and a disinfection test. And to know function of these instruments we test a negative pressure and maintain attached cups until 5 to 10minutes. Results : All results of experiments(impacted test, disinfection test, falling test) on stability of cups and air pumps are suitable for medical instrument. And the efficiency of 3 major makers shows various results. Negative pressure of B group is the highest, C group is the second, A group is the lowest. Pressure maintenance test shows A and C group is comparatively up to the experimental standard(<10%), B group is comparatively below the experimental standard(<10%). Conclusions : Results show stability of cups and air pumps is suitable for medical instruments. And negative pressure of cupping and maintenance of pressure show various results. So it is necessary to set up a standard negative pressure of cupping and maintenance of pressure.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
• /
• pp.276-280
• /
• 2001

In this paper, an approach to the design of negative impedance stabilizing controllers for PWM DC/DC converters that are used in DC switching. power supplies with constant power loads is presented. The control approach is based on the feedback linearization technique. Because of the negative impedance destabilizing characteristics of constant power loads, classical linear control methods have stability limitations around the operating points. However, the proposed stabilizing technique improves large-signal stability and dynamic responses. The proposed controllers are simulated and their responses under different operations are studied. Stability of the control technique is also verified using the second theorem of Lyapunov.

• 대한전자공학회논문지
• /
• 제10권5호
• /
• pp.7-15
• /
• 1973

부귀환펄스선형증폭기에 단계전압과 방사능검출기에서 나오는 펄스와 같이 빠른 펄스를 인가하였을 경우의 이득 안정도에 관하여 해석하였고 실험하였다. 이들 빠른 입력전압이 부귀환증폭기에 인가되면 출력전압의 선형도와 안정도는 증폭기의 rise time의 수배가 경과하여야 부귀효과가 나타난다. 이 제한을 주리기 위하여는 부귀환증폭기의 rise time을 계측할려는 입력펄스의 폭보다 적도록 설계하여야 한다는 것을 표시하였다.

• The Journal of Asian Finance, Economics and Business
• /
• 제9권3호
• /
• pp.347-354
• /
• 2022

This article examines the influence of Basel III reforms, risk management, and banking sector efficiency on banks' financial stability in emerging countries. The data for this study is collected from various sources. Based on the GDP classification of IMF, the top 22 countries were selected as the sample. The sampling frame includes all six regions of the world including 482 banks and 3022 observations in total. The empirical analysis is carried out by estimating the random effects models. It is found that the effects of capital buffer, liquidity, and risk management practices are significant on financial stability. It is also noticed that the capital buffer has a constructive and significant influence on financial stability. However, liquidity management shows a mixed impact, as in some countries, its impact is positive and significant while, in other countries, it is insignificant. Risk management practices have an overall positive influence on financial stability in the case of large economies. However, results are insignificant in the case of small economies. Bank-specific variables, namely profitability, size, and efficiency have a positive whereas, loan quality has a negative impact on financial stability in the emerging countries. GDP has a positive impact on financial stability whereas inflation and unemployment both have a negative effect on financial stability.

• International Journal of Automotive Technology
• /
• 제5권1호
• /
• pp.61-67
• /
• 2004

This paper suggests two simple two-degree-of-freedom models to describe the dynamical interaction between the pad and the disc of a disc brake system. Separate models for in-plane and out -of-plane vibration are described. Although a brake pad and disc have many modes of vibration, the interaction between a single mode of each component is considered as this is thought to be crucial for brake noise. For both models, the pad and the disc are connected by a sliding friction interface having a velocity dependent friction coefficient. In this paper, it is shown that this friction model acts as negative damping in the system that describes the in-plane vibration, and as negative stiffness in system that describes the out-of-plane vibration. Stability analysis is performed to investigate the conditions under which the systems become unstable. The results of the stability analysis show that the damping is the most important parameter for in-plane vibration, whereas the stiffness is the most important parameter for the out-of-plane vibration.

• 한국항행학회논문지
• /
• 제18권5호
• /
• pp.501-507
• /
• 2014

음이 아닌 입력에 대하여 음이 아닌 초기상태에서 출발한 모든 상태변수 값들이 시간에 대하여 항상 음이 아닌 값을 유지하는 시스템은 양의 시스템으로 정의된다. 본 논문에서는 상태변수에 시변 지연시간이 있는 양의 시변 선형 이산 구간 시스템의 안정조건을 새롭게 제안한다. 시변 지연시간은 최소와 최대 지연시간 범위에서 변하는 것으로 고려된다. 제안된 안정조건은 리아프노프 방정식의 상한 해 한계를 이용하여 유도되며, 매우 간단한 부등식의 형태로 표현된다. 수치예제를 통하여 새로운 안정조건들이 안정성 판단에 간단하고 효과적으로 적용될 수 있음을 확인한다.

• 한국항행학회논문지
• /
• 제23권6호
• /
• pp.577-583
• /
• 2019

음이 아닌 입력에 대하여 음이 아닌 초기상태에서 출발한 모든 상태변수 값들이 시간에 대하여 항상 음이 아닌 값을 유지하는 시스템은 양의 시스템으로 정의된다. 본 논문에서는 상태변수에 시변 지연시간과 비구조화된 불확실성이 함께 존재하는 양의 시변 선형 이산 구간 시스템의 안정조건을 새롭게 제안한다. 시변 지연시간은 변동가능한 최소와 최대 지연시간 범위 내에서 변하는 것으로 고려되며, 불확실성은 비선형성을 포함하여 그 최대 크기만을 알 수 있는 것으로 고려한다. 제안된 안정조건은 이전의 결과들이 시불변시스템에만 적용되었거나 불확실성에 대한 고려가 없었던 것을 개선한 것으로 매우 간단한 부등식의 형태로 표현된다. 안정조건은 리아프노프 안정이론을 이용하여 유도되며, 리아프노프 방정식의 상한 해 한계(upper solution bound)를 이용한 기존 결과에 비하여 많은 장점을 갖는다. 제안된 안정조건은 기존의 결과들을 포함하는 효과적인 것으로 수치예제를 통하여 이를 검증한다.