• 한국전자파학회논문지
• /
• 제18권5호
• /
• pp.547-552
• /
• 2007

본 논문에서는 두 마이크로스트립 라인으로 이루어진 헤어핀 형태의 결합 선로를 이용하여 특성이 개선된 링 하이브리드를 설계하였다. 제안한 구조는 링 하이브리드의 $\lambda/4$ 라인에 헤어핀 형태의 결합 선로를 삽입하여 두 선로가 가까워짐에 따라 선로간의 커플링으로 세 개의 감쇠극이 생겨 넓은 저지대역을 갖는 결합 선로 구조를 이용하여 구성함으로써 링 하이브리드의 크기 감소뿐만 아니라 고조파 제거 특성도 부가하였다. 중심 주파수 2.55 GHz에서 일반적인 링 하이브리드와 특성이 같고 3차 고조파를 포함한 12 GHz까지 -20 dB 이하의 고조파 저지 특성을 가지고 있다. 또한 링 부분의 크기는 기존 링 하이브리드의 1/4 크기로 줄어들었다. 제작된 링 하이브리드의 측정된 주파수 특성 결과는 시뮬레이션 결과와 잘 일치한다.

• Journal of applied mathematics & informatics
• /
• 제17권1_2_3호
• /
• pp.771-778
• /
• 2005

In this paper we shall give some group properties derived from the characteristic ring-module $_X(M)$, using the fact that $_X(M)_H$ is a conjugate to $_X(M)_{Ha}$ when M is an invertible right R-module. Also we shall prove that_X(M)$ is group-isomorphic to TR and some normal subgroup properties if M is invertible and R is commutative.

• 한국전자파학회:학술대회논문집
• /
• 한국전자파학회 2002년도 종합학술발표회 논문집 Vol.12 No.1
• /
• pp.136-140
• /
• 2002

In this paper, newly constructed 5.6 ㎓ ring resonator by using a T-Junction and a parallel transmission line. The resonator's size reduced twice more than a current ring and a hair-pin resonator at this paper's center frequency The loaded Q value is 240∼250 at center frequency. also, It was explained by RLC equivalent equation for the resonator.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2000년도 춘계학술대회논문집
• /
• pp.1925-1932
• /
• 2000

Damage detection methods using vibration modes are investigated on ring structures and. modal behavior of the slightly asymmetric rings is examined. Mode shapes changes, MSER(modal strain energy ratio) and MCR(modal curvature ratio) are applied to identify the locations of faults or damages. Parameters are calculated and compared by finite element analysis on rings with designed local damages. Damages are modeled as reduced stiffness in the analysis. The results show MSER and MCR can be proper factors to detect local damages in ring structures.

• 대한수학회보
• /
• 제49권3호
• /
• pp.511-515
• /
• 2012

We first show that the semiprimeness, primeness, and reducedness can go up to up-monoid rings. By these results we can compute the lower nilradicals of up-monoid rings, from which the well-known fact of Amitsur and McCoy for the polynomial rings can be extended to up-monoid rings.

• Korean Journal of Mathematics
• /
• 제7권2호
• /
• pp.215-218
• /
• 1999

We investigate characterizations of rings whose simple singular right R-modules are GP-injective. It is proved that if R is a semiprime ring whose simple singular right R-modules are GP-injective, then the center $Z(R)$ of R is a von Neumann regular ring. We consider the condition ($^*$): R satisfies $l(a){\subseteq}r(a)$ for any $a{\in}R$. Also it is shown that if R satisfies ($^*$) and every simple singular right R-module is GP-injective, then R is a reduced weakly regular ring.

• Journal of applied mathematics & informatics
• /
• 제41권6호
• /
• pp.1173-1180
• /
• 2023

In this paper, rings in which essential maximal right ideals are GP-injective are studied. Whether the rings with this condition satisfy von Neumann regularity is the goal of this study. The obtained research results are twofold: First, it was shown that this regularity holds even when the reduced ring is replaced with π-IFP and NI-ring. Second, it was shown that this regularity also holds even when the maximal right ideal is changed to GW-ideal. This can be interpreted as an extension of the existing results.

• 한국생산제조학회지
• /
• 제19권5호
• /
• pp.622-630
• /
• 2010

The increase of the spindle speed to enhance the productivity in ring spinning processes has been limited by yarn tension and heat generation of the traveller/ring. The main causes of yarn tension are 1) the force added directly to the yarn by the rotation of the spindle and 2) the centrifugal force exerted by the yarn balloon generated by traveller rotation. The dominant causes of heat generation are 1) the friction between the ring and traveller and 2) the friction between the traveller and yarn. These factors cause yarn end-breaks and heat damage. In the case of the staple yarn manufacturing process for PET (polyester) and nylon (a heat plasticity material), the rotational speed of the ring spinning system has deteriorated to 10,000rpm. The objective of this study was to develop a rotating ring which has dynamic stability, high productivity and a simple structure to overcome the limitations of the conventional fixed ring/traveller system. The results of this study revealed that the spinning tension could be reduced by 67.8% using the newly developed rotating ring.

• 대한수학회지
• /
• 제56권2호
• /
• pp.539-558
• /
• 2019

An ideal of a commutative ring is called a d-ideal if it contains the annihilator of the annihilator of each of its elements. Denote by DId(A) the lattice of d-ideals of a ring A. We prove that, as in the case of f-rings, DId(A) is an algebraic frame. Call a ring homomorphism "compatible" if it maps equally annihilated elements in its domain to equally annihilated elements in the codomain. Denote by $SdRng_c$ the category whose objects are rings in which the sum of two d-ideals is a d-ideal, and whose morphisms are compatible ring homomorphisms. We show that $DId:\;SdRng_c{\rightarrow}CohFrm$ is a functor (CohFrm is the category of coherent frames with coherent maps), and we construct a natural transformation $RId{\rightarrow}DId$, in a most natural way, where RId is the functor that sends a ring to its frame of radical ideals. We prove that a ring A is a Baer ring if and only if it belongs to the category $SdRng_c$ and DId(A) is isomorphic to the frame of ideals of the Boolean algebra of idempotents of A. We end by showing that the category $SdRng_c$ has finite products.

• Kyungpook Mathematical Journal
• /
• 제43권4호
• /
• pp.587-592
• /
• 2003

A near-ring N is called strongly reduced if, for $a{\in}N$, $a^2{\in}N_c$ implies $a{\in}N_c$, where $N_c$ denotes the constant part of N. We investigate some properties of strongly reduced near-rings and apply those to the study of left strongly regular near-rings. Finally we classify all reduced, and strongly reduced near-rings of order ${\leq}7$.