• Journal of Astronomy and Space Sciences
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• 제39권2호
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• pp.35-42
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• 2022

During their respective missions, the spacecraft Voyager and Cassini measured several Saturn magnetosphere parameters at different radial distances. As a result of information gathered throughout the journey, Voyager 1 discovered hot and cold electron distribution components, number density, and energy in the 6-18 Rs range. Observations made by Voyager of intensity fluctuations in the 20-30 keV range show electrons are situated in the resonance spectrum's high energy tail. Plasma waves in the magnetosphere can be used to locate Saturn's inner magnetosphere's plasma clusters, which are controlled by Saturn's spin. Electromagnetic electron cyclotron (EMEC) wave ring distribution function has been investigated. Kinetic and linear approaches have been used to study electromagnetic cyclotron (EMEC) wave propagation. EMEC waves' stability can be assessed by analyzing the dispersion relation's effect on the ring distribution function. The primary goal of this study is to determine the impact of the magnetosphere parameters which is observed by Cassini. The magnetosphere of Saturn has also been observed. When the plasma parameters are increased as the distribution index, the growth/damping rate increases until the magnetic field model affects the magnetic field at equator, as can be seen in the graphs. We discuss the outputs of our model in the context of measurements made in situ by the Cassini spacecraft.

• Journal of Astronomy and Space Sciences
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• 제39권2호
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• pp.67-77
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• 2022

The elements that impact the dynamics and collaborations of waves and particles in the magnetosphere of planets have been considered here. Saturn's internal magnetosphere is determined by substantiated instabilities and discovered to be an exceptional zone of wave activity. Interchanged instability is found to be one of the responsible events in view of temperature anisotropy and energization processes of magnetospheric species. The generated active ions alongside electrons that constitute the populations of highly magnetized planets like Saturn's ring electron current are taken into consideration in the current framework. The previous and similar method of characteristics and the perturbed distribution function have been used to derive dispersion relation. In incorporating this investigation, the characteristics of electromagnetic ion cyclotron wave (EMIC) waves are determined by the composition of ions in plasmas through which the waves propagate. The effect of ring distribution illustrates non-monotonous description on growth rate (GR) depending upon plasma parameters picked out. Observations made by Cassini found appropriate for modern study, have been applied to the Kronian magnetosphere. Using Maxwellian ring distribution function of ions and detailed mathematical formulation, an expression for dispersion relation as well as GR and real frequency (RF) are evaluated. Analysis of plasma parameters shows that, proliferating EMIC waves are not developed much when propagation is parallelly aligned with magnetosphere as compared to waves propagating in oblique direction. GR for the oblique case, is influenced by temperature anisotropy as well as by alternating current (AC) frequency, whereas it is much affected only by AC frequency for parallel propagating waves.

• 충청수학회지
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• 제25권4호
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• pp.771-777
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• 2012

We give a result on the density of certain additive arithmetic functions which count the number of restricted irreducible polynomials on the polynomial ring.

• Advances in concrete construction
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• 제14권1호
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• pp.35-43
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• 2022

Based on novel Galerkin's technique, the theoretical study gives a prediction to estimate the vibrations of FG rotating cylindrical shell. Terms of ring supports have been introduced by a polynomial function. Three different laws of volume fraction are utilized for the vibration of cylindrical shells. Variation frequencies with the locations of ring supports have been analyzed and these ring supports are placed round the circumferential direction. The base of this approach is an approximate estimation of eigenvalues of proper functions which are the results of solutions of vibrating equation. Each longitudinal wave number corresponds to a particular boundary condition. The results are given in tabular and graphical forms. By increasing different value of height-to-radius ratio, the resulting backward and forward frequencies increase and frequencies decrease on increasing length-to-radius ratio. There is a new form of frequencies is obtained for different positions of ring supports, which is bell shaped. Moreover, on increasing the rotating speed, the backward frequencies increases and forward frequencies decreases.

• 한국전자파학회논문지
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• 제15권1호
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• pp.60-67
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• 2004

본 논문에서는 디세그멘테이션 기법을 이용하여 사각 링 패치 안테나를 해석하였으며, 그린함수로부터의 직사각형 세그먼트의 임피던스 계산과 평면 전자기 구조체에 대한 디세그멘테이션 방법이 논의되고 있다. 사각 링 캐버티는 큰 사각형 캐버티에서 작은 사각형 캐버티를 빼낸 구조이므로, 사각형 캐버티에 대한 그린함수의 항으로 표현된 각각의 임피던스 행렬들에 다 단자 결합법을 적용하여 사각 링 캐버티의 전체 임피던스 매트릭스를 구한다. 전자계는 8개 경계조건을 만족하는 벡터 포텐셜로부터 구할 수 있다. 각 에지에서의 전자계 분포는 여기된 모드에 따라 막대 그래프로 표현하였다. 이 결과를 이용하여 사각 링 패치 안테나의 동작모드를 분석할 수 있다.

• 소성∙가공
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• 제1권1호
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• pp.33-41
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• 1992

Sintered P/M connecting rod is forged to increase density and to satisfy dimensional specifications. Flow of the materials is different form that of wrought materials due to pores in the preform. The Mises yield function was modified to. include the first invariant of stress tensor, and the associated flow rule was derived by applying the normality rule to the yield function. Axisymmetric and plane-strain finite element analyes were carried out for the ring and beam portions of the connecting rod, respectively. The flow of the preform and density change of the analysis are presented in this paper. A load-stroke curve was also presented by superimposing analysis results for the ring and beam portions.

• 전기학회논문지
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• 제56권9호
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• pp.1521-1526
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• 2007

This paper presents the application of Adaptive Evolutionary Algorithm (AEA) to search an optimal setting of overcurrent relay coordination to protect ring distribution systems. The AEA takes the merits of both a genetic algorithm (GA) and an evolution strategy (ES) in an adaptive manner to use the global search capability of GA and the local search capability of ES. The overcurrent relay settings and coordination requirements are formulated into a set of constraint equations and an objective function is developed to manage the overcurrent relay settings by the Time Coordination Method. The domain of overcurrent relays coordination for the ring-fed distribution systems is a non-linear system with a lot of local optimum points and a highly constrained optimization problem. Thus conventional methods fail in searching for the global optimum. AEA is employed to search for the optimum relay settings with maximum satisfaction of coordination constraints. The simulation results show that the proposed method can optimize the overcurrent relay settings, reduce relay mis-coordinated operations, and find better optimal overcurrent relay settings than the present available methods.

• 생약학회지
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• 제23권4호
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• pp.201-210
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• 1992

Scutellariae plants contain a large number of flavonoids and in addition, many of them are with unusual A- and/or B-ring substitutions. The total number of flavonoids reported up to the middle of 1991 are 137 including 89 of flavones, flavonols and their glycosides including 3 C-glycosides$(1{\sim}89)$, 39 of flavanones, dihydroflavonols and their glycosides $(90{\sim}128)$, 8 of chalcones $(129{\sim}136)$ and one biflavonoid, 8, 8'-bibaicalein(137). More than half of the flavonoids are with either unusual 5-metboxy(2'-methoxy in case of chalcones) in A-ring and/or 2'-oxygenation(2-oxygenation in case of chalcones) in B-ring substitutions. Four flavones, four flavanones and two chalcones are with methylation at 5-OH(2'-OH in case of chalcones) and six of them also have 2'-oxygenations(2- in case of chalcones). Sixtyeight out of total 137 flavonoids have oxygenated substitution at 2'-(2- in case of chalcones) position of B-ring and in addition, 27 of them have another oxygen function at 6'-(6- in case of chalcones) and 18 of them have additional oxygen substitutions either at 3'-, 5'-,3',6'-or 3', 4', 5'-(3, 4, 5- in case of chalcones) positions. The distribution and isolation of flavonoid components of Scutellariae plants are tabulated with references.

• 한국농림기상학회지
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• 제17권2호
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• pp.93-101
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• 2015

본 연구는 연륜연대학적 방법을 적용하여 상수리나무의 연륜생장과 기후인자와의 관계분석을 실시하기 위해 수행하였다. 이를 위해 2006년부터 2010년까지 실시된 제5차 국가산림자원조사의 임목조사 자료에 포함된 연륜생장 자료를 활용하였다. 연륜생장과 기후인자와의 관계를 구명하기 위해 월평균 기온과 월강수량 자료를 연도별로 정리한 후 연륜생장 자료를 수집된 시군별로 분류하여 정리하였다. 상수리나무가 분포하는 지역에 대한 기후조건의 유사성에 근거하여 연륜생장 자료의 군집분석을 실시한 결과 4개의 군집으로 분석되었다. 또한 크로스데이팅과 표준화를 실시하여 상수리나무의 군집별 지표연대기를 작성한 후 기초통계량을 산출하여 지표연대기의 적합성을 검정하였으며, 군집별 연륜생장과 기후인자와의 관계 구명을 위해 반응함수 분석을 실시하였다. 본 연구에서 얻은 상수리나무의 연륜생장과 기후인자 간의 통계적인 분석결과를 기반으로 기후변화에 따른 중장기 생장변화의 예측에 필요한 정보를 제공할 수 있을 것으로 기대된다.

• 한국전기전자재료학회논문지
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• 제17권5호
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• pp.552-559
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• 2004

In recent, there have been several developments in lamp technology that promise savings in electrical power consumption and improved quality of the lighting space. Above all, the advantage of ring-shaped electrodeless fluorescent lamp is the removal of internal electrodes and heating filaments that are a light-limiting factor of conventional fluorescent lamps. The ring-shaped electrodeless lamp is intended as a high efficiency replacement for the incandescent reflector lamp in many applications. Therefore, the life time of ring-shaped electrodeless fluorescent lamps is substantially higher than that of conventional fluorescent lamps and last up to 60,000 hours. In this paper, maxwell 3D finite element analysis program(Ansoft) was used to obtain electromagnetic properties associated with the coil and nearby structures. The electromagnetic emitting properties were presented by 3D simulation software operated at 250 KHz and some specific conditions. The optical characteristics were measured luminance and a temperature and an optical spectrum distribution for 10 min in a one minute interval at the same time. With a goal of finding alternative materials, we show measurement results of electrical characteristics of a ring-shaped electrodeless fluorescent lamp as a function of frequency and the number of coil turns using a highly permeable($\mu$$_{r}$(equation omitted) 2,000) Mn-Zn ferrite. These results are compared with those of conventional ring-shaped electrodeless fluorescent lamp. It is found that the resistance, inductance and impedance are increased while the quality factor decreases as frequency increases.s.