• 대한수학회논문집
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• 제30권4호
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• pp.385-402
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• 2015

In this paper we study the (good) semi-prime closure operations on ideals of a BCK-algebra, lower BCK-semilattice, Noetherian BCK-algebra and meet quotient ideal and then we give several theorems that make different (good) semi-prime closure operations. Moreover by given some examples we show that the given different notions are independent together, for instance there is a semi-prime closure operation, which is not a good semi-prime. Finally by given the notion of "$c_f$-Max X", we prove that every member of "$c_f$-Max X" is a prime ideal. Also we conclude some more related results.

• East Asian mathematical journal
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• 제28권3호
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• pp.281-285
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• 2012

In this paper, the concept of *-prime ideals in non-associative near-rings is introduced and then will be studied. For this purpose, first we introduce the notions of *-operation, *-prime ideal and *-system in a near-ring. Next, we will define the *-sequence, *-strongly nilpotent *-prime radical of near-rings, and then obtain some characterizations of *-prime ideal and *-prime radical $r_s$(I) of an ideal I of near-ring N.

• Journal of Advanced Marine Engineering and Technology
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• 제21권2호
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• pp.166-177
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• 1997

The prime mover performance of on - board Diesel Generator is well characterized by the variation of frequency and the load sharing on parallel running under electric load change. This study is aimed to configure the modeling for performance simulation regarding to DG operation which could be interested for education purpose or system analysis. The modeling had been made on the base of modules such as govenor, prime mover of diesel engine and generator with electric load system, which were then intergrated for total simula¬tion performance. One real model system has been introduced for deciding relating parameters and for the comparison of resulting performance in simulation. The responses from the modelling were confirmed in single and paralell operation, the results of which showed resonable accordance with the real system.

• 한국병원경영학회지
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• 제19권1호
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• pp.32-42
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• 2014

It is necessary to calculate prime cost of medical services accurately in order to evaluate the adequacy of medical fee. This paper aims to identify cost analysts' perception on prime cost of medical services and needs in establishing a cost accounting system in hospitals, proposing future directions and guidelines for the calculation of medical fee. A self-administered questionnaire and telephone survey on operation of a hospital cost-accounting system was conducted in November, 2012, among cost analysts currently working in the hospitals and hospital administrators planning to implement the hospital cost-accounting system. Our study shows that most of the cost analysts were aware of the importance of calculating prime cost and responded that collection of the prime cost data from government is necessary although they are less likely to provide the data in the future concerning the risk of data misuse and data security. They also responded that lack of budget allocation and excessive workload were the main reasons for not estimating the prime cost and operating cost management information system. Results show that hospital cost analysts considered the data accuracy is the most critical factor in calculating prime costs of medical services. However, there was no investment budget allocated in some hospitals or limited to less than 100 million, indicating that hospitals are reluctant to invest on implementing the cost accounting system. Respondents stated the organization that collects the prime cost of medical services among hospitals should display strong analytical capabilities, ensure data security, and maintain independence, which is most demanded. There are 57 hospitals that calculated the prime cost of medical services for 2012 by each medical department and 20 hospitals that calculated the prime cost by fee-for-services, aiming to establish a cost accounting system. Our results indicate that hospitals should voluntarily provide the accurate prime cost for medical services in order to properly evaluate the adequacy of medical fee. Consequently, it is critical to establish an independent organization to collect and appraise the data. It is also recommended that government should implement various policies to encourage hospitals to participate in the data collection to achieve the data accuracy and representativeness.

• East Asian mathematical journal
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• 제27권1호
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• pp.75-82
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• 2011

In this paper, we will introduce the concept of fuzzy mulitplication module. We will define a new operation called a product on th family of all fuzzy submodules of a fuzzy mulitplication module. We will define a fuzzy subset of the idealization ring R+M and find some relations with the product of fuzzy submodules and product of fuzzy ideals of the idealization ring R+M. Some properties of weakly fuzzy prime submoduels and fuzzy prime submodules which are de ned by T.K.Mukherjee M.K.Sen and D.Roy will be introduced. We will investigate some properties of fuzzy prime submodules of a fuzzy multiplication module.

• 대한수학회지
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• 제60권2호
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• pp.407-464
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• 2023

Let R be a commutative ring with identity. The structure theorem says that R is a PIR (resp., UFR, general ZPI-ring, π-ring) if and only if R is a finite direct product of PIDs (resp., UFDs, Dedekind domains, π-domains) and special primary rings. All of these four types of integral domains are Krull domains, so motivated by the structure theorem, we study the prime factorization of ideals in a ring that is a finite direct product of Krull domains and special primary rings. Such a ring will be called a general Krull ring. It is known that Krull domains can be characterized by the star operations v or t as follows: An integral domain R is a Krull domain if and only if every nonzero proper principal ideal of R can be written as a finite v- or t-product of prime ideals. However, this is not true for general Krull rings. In this paper, we introduce a new star operation u on R, so that R is a general Krull ring if and only if every proper principal ideal of R can be written as a finite u-product of prime ideals. We also study several ring-theoretic properties of general Krull rings including Kaplansky-type theorem, Mori-Nagata theorem, Nagata rings, and Noetherian property.

• 대한수학회지
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• 제54권6호
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• pp.1699-1731
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• 2017

In this note, we define and compare some closures which behave somewhat like the radical closure. Using these closures as a starting point allows us to classify all semiprime closures on the nodal curve. Several examples provided show how these closures can differ significantly in the non-Noetherian setting.

• Korean Journal of Mathematics
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• 제17권1호
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• pp.15-23
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• 2009

Let D be an integral domain, P be a nonzero prime ideal of D, $\{P_{\alpha}{\mid}{\alpha}{\in}{\mathcal{A}}\}$ be a nonempty set of prime ideals of D, and $\{I_{\beta}{\mid}{\beta}{\in}{\mathcal{B}}\}$ be a nonempty family of ideals of D with ${\cap}_{{\beta}{\in}{\mathcal{B}}}I_{\beta}{\neq}(0)$. Consider the following conditions: (i) If $P{\subseteq}{\cup}_{{\alpha}{\in}{\mathcal{A}}}P_{\alpha}$, then $P=P_{\alpha}$ for some ${\alpha}{\in}{\mathcal{A}}$; (ii) If ${\cap}_{{\beta}{\in}{\mathcal{B}}}I_{\beta}{\subseteq}P$, then $I_{\beta}{\subseteq}P$ for some ${\beta}{\in}{\mathcal{B}}$. In this paper, we prove that D satisfies $(i){\Leftrightarrow}D$ is a generalized weakly factorial domain of ${\dim}(D)=1{\Rightarrow}D$ satisfies $(ii){\Leftrightarrow}D$ is a weakly Krull domain of dim(D) = 1. We also study the t-operation analogs of (i) and (ii).

• 문화기술의 융합
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• 제9권3호
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• pp.287-292
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• 2023

미국 항공우주국(NASA)은 저고도의 공중을 새롭게 구축하고자 도시의 단거리 항공 운송 생태계를 새로운 개념의 도심항공모빌리티(Urban Air Mobility, UAM)을 제시하여 현재 UAM이라는 용어가 전 세계적으로 통용되고 있다. 이러한 패러다임은 우리나라 정부에서도 2025년까지 도심항공교통 서비스 상용화를 목표로 추진하고 있는 실정이며 더 나아가 급변하는 미래 작전환경 및 전장 공간의 확장으로 공중기동·수송능력 확보 필요성이 대두되고 있어 우리나라 군 조직에서도 필요성이 제기되는 부분이다. 즉, 본 연구는 미 공군의 'Agility Prime' 프로그램을 소개하여 군사적 필요성과 군사적 운용방안에 대해 제시하고자 출발한 연구이며 연구의 체계는 도심항공 모빌리티 배경 및 개념, 한국형 도심항공 모빌리티 발전 추세, 미 공군의 'Agility Prime' 프로그램 분석 순으로 구성하였으며 본 연구에 이어서 후속연구로 진행되길 기대한다.

• 한국건설관리학회논문집
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• 제15권2호
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• pp.44-52
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• 2014

2013년 3월 정부에서는 공공공사에 분리발주방식을 확대적용하는 정책을 발표하였다. 분리발주방식의 도입을 두고 건설참여자들의 입장이 첨예하게 대립하게 되고, 건설분야의 뜨거운 이슈가 되고 있는 상황이다. 건설공사 관리의 경험이 부족한 공공발주자가 다수로 분리된 전문공종들을 직접관리하여 인터페이스의 증가에 따른 관리비용 상승, 실적 부족으로 인한 관리비용 산정 기준이 없어 사업운영에 어려움이 있는 현실이다. 따라서, 본 연구에서는 분리발주의 관리비용율 예측할 수 있는 모델을 개발하여 효율적인 분리발주의 운영이 가능하게 하는 것을 목적으로 하고 있다.