• Journal of the Korean Mathematical Society
• /
• v.34 no.1
• /
• pp.13-21
• /
• 1997

In recent years M. Hochster and C. Huneke introduced the notions of tight closure of an ideal and of the weak F-regularity of a ring of positive prime characteristic. Here 'F' stands for Frobenius. This notion enabled us to play an important role in a commutative ring theory, and other related topics.

• Journal of the Korean Mathematical Society
• /
• v.54 no.6
• /
• pp.1699-1731
• /
• 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.

• Honam Mathematical Journal
• /
• v.24 no.1
• /
• pp.1-8
• /
• 2002

In this paper we will show that if E is an injective module over a commutative ring A, then the sequence of sets $Ass_{A}(A/I^{n})^{*(E)}),\;n{\in}N,$ is increasing and ultimately constant. Also we will obtain some results concerning the integral closure of ideals related to some modules.

• Journal of applied mathematics & informatics
• /
• v.38 no.1_2
• /
• pp.65-77
• /
• 2020

In this paper, for any non-empty subsets A, I of a pseudo BCI-algebra X, we introduce the concept of pseudo p-closure of A with respect to I, denoted by A^pc_I, and investigate some related properties. Applying this concept, we state a necessary and sufficient condition for a pseudo BCI-algebra 1) to be a p-semisimple pseudo BCI-algebra; 2) to be a pseudo BCK-algebra. Moreover, we show that A^pc_{0} is the least positive pseudo ideal of X containing A, and characterize it by the union of some branches. We also show that the set of all pseudo ideals of X which A^pc_I = A, is a complete lattice. Finally, we prove that this notion can be used to define a closure operation.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.31 no.1 s.256
• /
• pp.40-50
• /
• 2007

The present contribution describes the application of elliptic-blending second moment closure to predict the gas cooling process of turbulent super-critical carbon dioxide flow in a square cross-sectioned duct. The gas cooling process under super-critical state experiences a drastic change in thermodynamic and transport properties. Redistributive terms in the Reynolds stress and turbulent heat flux equations are modeled by an elliptic-blending second moment closure in order to represent strongly non-homogeneous effects produced by the presence of walls. The main feature of Durbin's elliptic relaxation second moment closure that accounts for the nonlocal character of pressure-velocity gradient correlation and the near-wall inhomogeneity guaranteed by the elliptic blending second moment closure.

• Proceedings of the KSME Conference
• /
• 2000.04a
• /
• pp.79-84
• /
• 2000

Crack closure and growth behavior of physically short fatigue cracks under random loading are Investigated by performing narrow- and wide-band random loading tests for various stress ratios. Artificially prepared two-dimensional, short through-thickness cracks are used. The closure behavior of short cracks under random loading is discussed, comparing with that of short cracks under constant-amplitude loading and also that of long cracks under random loading. Irrespective of random loading spectrum or block length, the crack opening load of short cracks is much lower under random loading than under constant-amplitude loading corresponding to the largest load cycle in a random load history, contrary to the behavior of long cracks that the crack opening load under random loading is nearly the same as or slightly higher than constant-amplitude results. This result indicates that the largest load cycle in a random load history has an effect to enhance crack opening of short cracks.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.25 no.6
• /
• pp.434-439
• /
• 2016

Optical fiber splice closure serves to protect connection parts from external environment. Moreover, it functions as a connection, junction, and distribution in diverse surroundings such as aerial, underground, duct, and pole. In this research, first, the optical fiber splice closure, its configuration, and the design problem were briefly investigated. Second, the design and application for in-line cable closure were studied to satisfy its construction and technical features. The injection molding conditions and optimal design were conducted to save time and cost during the manufacturing process. Third, methods to minimize loss via of optical fiber cable while strongly fixing optical fiber cable with optical cable holder to prevent fracture were researched, and tests such as perfect air tightness and mechanical and environmental performance were conducted.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.10 no.6
• /
• pp.898-905
• /
• 1986

In order to obtain the microstructure improving fatigue crack propagation resistance of steels, fatigue crack propagation behavior of martensite-ferrite dual phase steels is investigated in terms of crack deflection and crack closure. The results obtained are as follows; (1) .DELTA.K$_{th}$ and fatigue crack propagation resistance in low .DELTA.K region increases with increasing hardness of second phase. But the difference of this crack propagation resistance decreases with increasing .DELTA.D. (2) In low .DELTA.K region, crack closure increases with increasing hardness of second phase, when the materials have all the sam volume fractionof second phase, or when yield strengths are similar in all materials. (3) These crack closure can be explained by fracture surface roughness due to crack deflection.n.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2010.11a
• /
• pp.217-220
• /
• 2010

This paper presents an achieving method of reducing maximum acceleration for the missile by decrease of burst pressure in a nozzle closure. The relation of notch shape and burst pressure for a nozzle closure is examined by experiment. In the point of maximum acceleration reduction for a missile, an improved nozzle closure effects well compared with that of a reference closure by ground burning test of a gas generator.

• Journal of Chest Surgery
• /
• v.22 no.5
• /
• pp.748-752
• /
• 1989

We experienced 6 patients with the sinus Valsalva aneurysm rupture during last 12 years [Jan. 1977-Sep. 1989]. Of them. 5 cases were reviewed. They consist of 3 males and 2 females, and the age ranged from 12 years to 40 years with the mean age of 25 years. 4 patients showed congestive heart failure symptoms. The diagnosis was made by 2D-Echo and cine-angiogram. In 4 patients. sinus Valsalva aneurysm ruptured from the Rt. coronary sinus to the Rt. ventricle, and in one from non-coronary sinus to the Rt. atrium. In 2 cases, resection of the aneurysm and simple stitch closure was made. Resection of the aneurysm k patch closure and AVR in one, closure of the fistula, AVR and patch closure of the associated VSD in one, and closure of the fistula, AVR k TVR in one were made in another 3 cases. There was no postoperative mortality case.