• Kyungpook Mathematical Journal
• /
• 제51권3호
• /
• pp.339-344
• /
• 2011

Let D be an integral domain with quotient field K, X be an indeterminate over D, and D[X] be the polynomial ring over D. A prime ideal Q of D[X] is called an upper to zero in D[X] if Q = fK[X] ${\cap}$ D[X] for some f ${\in}$ D[X]. In this paper, we study integral domains D such that every upper to zero in D[X] contains a prime element (resp., a primary element, a t-invertible primary ideal, an invertible primary ideal).

• 대한기계학회논문집A
• /
• 제23권7호
• /
• pp.1120-1128
• /
• 1999

An elastic-viscoplastic finite element analysis is performed to investigate detailed growth behavior of creep cracks and the numerical results are compared with experimental results. In Cr-Mo steel stress fields obtained from the crack growth method by mesh translation were compared with both cases that the secondary creep rate is only used as creep material property and the primary creep rate is included. Analytical stress fields, Riedel-Rice(RR) field, Hart-Hui-Riedel(HR) field and Prime(named in here) field, and the results obtained by numerical method were evaluated in details. Time vs. stress at crack tip was showed and crack tip stress fields were plotted. These results were compared with analytical stress fields. There is no difference of stress distribution at remote region between the case of 1st creep rate+2nd creep rate and the case of 2nd creep rate only. In case of slow velocity of crack growth, the effect of 1st creep rate is larger than the one of fast crack growth rate. Stress fields at crack tip region we, in order, Prime field, HR field and RR field from crack tip.

• Korean Journal of Mathematics
• /
• 제19권2호
• /
• pp.163-169
• /
• 2011

Let D be an integral domain, S be a multiplicative subset of D such that DS is a PID, and D[X] be the polynomial ring over D. We show that S is an almost splitting set in D if and only if every nonzero prime ideal of D disjoint from S contains a primary element. We use this result to give a simple proof of the known result that D is a UMT-domain and Cl(D[X]) is torsion if and only if each upper to zero in D[X] contains a primary element.

• Kyungpook Mathematical Journal
• /
• 제46권2호
• /
• pp.261-271
• /
• 2006

In this paper, we investigate and characterize the class of A-semirings. A characterization of the Thierrin radical of a proper ideal of an A-semiring is given. Moreover, when P is a Q-ideal in the semiring R, it is shown that P is primary if and only if R/P is nilpotent.

• 대한수학회보
• /
• 제52권4호
• /
• pp.1253-1268
• /
• 2015

It is well known that an integral domain D is a UFD if and only if every nonzero prime ideal of D contains a nonzero principal prime. This is the so-called Kaplansky's theorem. In this paper, we give this type of characterizations of a graded PvMD (resp., G-GCD domain, GCD domain, $B{\acute{e}}zout$ domain, valuation domain, Krull domain, ${\pi}$-domain).

• 대한수학회보
• /
• 제30권1호
• /
• pp.71-77
• /
• 1993

Every ring considered in the paper will be assumed to be commutative and have a unit element. An ideal A of a ring R will be called primal if the elements of R which are zero divisors modulo A, form an ideal of R, say pp. If A is a primal ideal of R, P is called the adjoint ideal of A. The adjoint ideal of a primal ideal is prime [2]. The definition of primal ideals may also be formulated as follows: An ideal A of a ring R is primal if in the residue class ring R/A the zero divisors form an ideal of R/A. If Q is a primary idel of a ring R then every zero divisor of R/Q is nilpotent; therefore, Q is a primal ideal of R. That a primal ideal need not be primary, is shown by an example in [2]. Let R[X], and R[[X]] denote the polynomial ring and formal power series ring in an indeterminate X over a ring R, respectively. Let S be a multiplicative system in a ring R and S$^{-1}$ R the quotient ring of R. Let Q be a P-primary ideal of a ring R. Then Q[X] is a P[X]-primary ideal of R[X], and S$^{-1}$ Q is a S$^{-1}$ P-primary ideal of a ring S$^{-1}$ R if S.cap.P=.phi., and Q[[X]] is a P[[X]]-primary ideal of R[[X]] if R is Noetherian [1]. We search for analogous results when primary ideals are replaced with primal ideals. To show an ideal A of a ring R to be primal, it sufficies to show that a-b is a zero divisor modulo A whenever a and b are zero divisors modulo A.

• Korean Journal of Mathematics
• /
• 제21권4호
• /
• pp.455-462
• /
• 2013

Let D be an integral domain, S be a saturated multi-plicative subset of D such that $D_S$ is a factorial domain, $\{X_{\alpha}\}$ be a nonempty set of indeterminates, and $D[\{X_{\alpha}\}]$ be the polynomial ring over D. We show that S is a splitting (resp., almost splitting, t-splitting) set in D if and only if every nonzero prime t-ideal of D disjoint from S is principal (resp., contains a primary element, is t-invertible). We use this result to show that $D{\backslash}\{0\}$ is a splitting (resp., almost splitting, t-splitting) set in $D[\{X_{\alpha}\}]$ if and only if D is a GCD-domain (resp., UMT-domain with $Cl(D[\{X_{\alpha}\}]$ torsion UMT-domain).

• Kyungpook Mathematical Journal
• /
• 제49권2호
• /
• pp.221-233
• /
• 2009

In this article, we generalize a well-known result of Hebisch and Weinert that states that a finite semidomain is either zerosumfree or a ring. Specifically, we show that the class of commutative semirings S such that S has nonzero characteristic and every zero-divisor of S is nilpotent can be partitioned into zerosumfree semirings and rings. In addition, we demonstrate that if S is a finite commutative semiring such that the set of zero-divisors of S forms a subtractive ideal of S, then either every zero-sum of S is nilpotent or S must be a ring. An example is given to establish the existence of semirings in this latter category with both nontrivial zero-sums and zero-divisors that are not nilpotent.

• 한국실내디자인학회논문집
• /
• 제16권6호
• /
• pp.56-64
• /
• 2007

This study is purposed to explicate the idea of 'the general design' for the construction of the construction of space of $L\'{a}szl\'{o}$ Moholy-Nagy who has stood against the traditional value system and made an attempt to create a new space-form language. On the basis of unification of perception and reality Moholy-Nagy intended to regenerate the essential aspects of life through an art by bestowing art with an aesthetic foundation and also expanding the art world into the living area. 'The Allgemeine Elementenlehre(the general theory of elements)' of Moholy-Nagy that is distanced from the visual perception as the dominant sense which is based on the principle of representation and imitation, and emphasized on the complicated relationship between the various senses including the tactile sense, offers a pedagogical basis for the space design that is indispensable for the plastic thinking and practice. At the same time it indicates an access route to the primary nature through the spatial construction of the prime elements of nature and man To explicate his idea toward the general theory of design of space, it will be tried first of all to clarify the core points of the empirio-criticism and the constructivism as the theoretical backgrounds of Moholy-Nagy. And then on the basis of these theoretical backgrounds will be analyzed the system and the contents of 'the allgemeine Elementenlehre' as the general space design theory and also the general space design pedagogy.

• 한국병원경영학회지
• /
• 제12권1호
• /
• pp.1-30
• /
• 2007

The study carried out a survey with employees of hospitals located in Daejeon, Chungnam, and Chungbuk from Sep. 12 to Sep. 30, 2005 in order to derive primary elements that affect the improvement of hospital's competitiveness. The study investigated and analyzed the employees' recognition on the change of competitive environment caused by the change of medical environment. The study also analyzed the elements that affect the hospital's competitiveness and the competitive strategies of the hospitals. The conclusion of this study can be summarized as follows. 1. Summary 1) Most of the employees responded that there is a rival in the competitive environment and the competitive is intense. Especially when the employees are married, live in urban areas, have an education level of university graduate or are managers, they tend to think the competitive is very intense. Also, they said that the competitive is based upon the quality of medical service. They mentioned the element that has the biggest effect on the competitiveness is the element of medical consumer and they recognized that the medical services in university and general hospitals have more competitiveness than the one-department hospitals. 2) It was investigated that the medical technique service has the most effect on the hospital's competitiveness. Also, the external service of medical techniques also has a large effect on the hospital's competitiveness. 3) When they were asked for the factors that affect the patients' decision on selecting a hospital, most of them responded "capability and technique of the medical staffs." Also, they said that "sufficient explanation from doctors" and "special center and clinic" are the factors that have big effects on the patients' decision. 4) In the SWOT analysis, most of them responded that the strength is the hospital's characteristics and the weakness is insufficient and obsolete equipment. They said the opportunity is the demands for professional medical service and the risk is the intense competitive among the hospitals. 5) In the SWOT strategy, they emphasized the strategy that uses the opportunity and the strength and the strategy that uses the opportunity while overcoming the weakness. 6) As for the basic competition strategy, most of them thought of the strategy of professionalizing the medical service most importantly. Next, they focused on the strategy of distinct service and the strategy of lower prime cost. 2. Conclusion 1) Because service competition between hospitals is happening seriously, need competitiveness security through right awareness transfer and satisfaction upgrade about medical consumer. 2) For medical technique service upgrade that equip Hospital's competitiveness but affects most, must solidify the countermeasure because professionalizing the medical service and newest medical technique induction should be achieved first, and compose task force for the external service of medical techniques improvement. 3) To improve SWOT of hospital, opportunity and the strength strategy choice that rescue hospital's characteristics heightening professionalizing the medical service level is fancied. 4) As for the basic competition strategy, will have to try in phase triangular position of hospital which is trusted medical level upgrade and excellent manpower security and finance independence through upgrade. The study was only done with hospitals in Daejeon, Chungnam and Chungbuk. Also, it is a study from the side of suppliers of medical service so there are limitations. However, the significance of the study is to present the basic data for improvement of hospital's competitiveness by examining the importance of medical techniques and external service of medical techniques that are the main effects on the improvement of hospital's competitiveness.