• Journal of the Korean Society for Nondestructive Testing
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• v.20 no.2
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• pp.110-115
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• 2000

The electromechanical reciprocity identity is introduced to relate the voltage at the terminals of a transducer to the acoustic wavefields scattered from the specimen. The voltage at the terminals of the transducer is expressed as an integral equation in terms of the displacement and stress of the incident and scattered waves on the closed surface enclosing the scatterer. The equation is used to relate the voltage at the terminals of an acoustic microscope's transducer to the acoustic wavefields at the interface between the specimen and the coupling fluid. The voltage calculated using the integral equation is compared with the experimental result.

• Korean Institute of Interior Design Journal
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• no.9
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• pp.38-48
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• 1996

The purpose of this paper is to study the artistic characteristics of light and adjustment in space, and how meaningful this integral phenomenon is to human beings , whin a space is transformed into a dynamic subject by light. When we create a very unique space we need to adjust light in all environments and must recognize the substance of light in all human spaces. The study of interior design is dependant on the existence of these lights in space. Light plays a very integral role in life having great contingency in the artistic characteristics represented in space. Light is a non-materialistic substance. However, when this substance is realized as a materialistic , light has a very visual effect, having a pleasing and satisfying effect on humans. The artistic characteristic of light in interior space are represented through elements of tranquility , direction . recognition, symbolism , and design. Light has a limitless amount of potential for giving humans boundless possibilities in space and expression . By studying psychological and physical aspects of the flow of light we are able to enjoy its fruitful benefits in the space of interior architectural design.

• Journal of the Korean Mathematical Society
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• v.60 no.2
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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.

• International Journal of Aeronautical and Space Sciences
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• v.3 no.2
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• pp.76-81
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• 2002

A numerical simulation of wake behavior behind three-dimensional wings in ground effect is done using an indirect boundary element method (Panel Method). An integral equation is obtained by applying Green's 2nd Identity on all surfaces of the flow domain. The AIC is constructed by imposing the no penetration condition on solid surfaces, and the Kutta at the wing's trailing edge. The ground effect is included using an image method. At each time step, a row of wake panels from wings' trailing edge are convected downstream following the force-free condition. The roll-up of wake vortices behind wings in close proximity is simulated.

• Journal of applied mathematics & informatics
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• v.39 no.5_6
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• pp.617-622
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• 2021

Let R be a commutative ring with identity, R[X] the polynomial ring over R and S a multiplicative subset of R. Let U = {f ∈ R[X] | f is monic} and let N = {f ∈ R[X] | c(f) = R}. In this paper, we show that if S is an anti-Archimedean subset of R, then R is an S-Noetherian ring if and only if R[X]_U is an S-Noetherian ring, if and only if R[X]_N is an S-Noetherian ring. We also prove that if R is an integral domain and R[X]_U is an S-principal ideal domain, then R is an S-principal ideal domain.

• Bulletin of the Korean Mathematical Society
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• v.56 no.2
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• pp.505-514
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• 2019

Let R be a commutative ring with identity and M be a unitary R-module. A submodule N of M is called a dense submodule if $Hom_R(M/N,\;E_R(M))=0$, where $E_R(M)$ is the injective hull of M. The R-module M is said to be monoform if any nonzero submodule of M is a dense submodule. In this paper, among the other results, it is shown that any kind of the following module is monoform. (1) The prime R-module M such that for any nonzero submodule N of M, $Ann_R(M/N){\neq}Ann_R(M)$. (2) Strongly prime R-module. (3) Faithful multiplication module over an integral domain.

• Korean Journal of Mathematics
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• v.29 no.1
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• pp.13-24
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• 2021

For a finite commutative ring R with identity 1 ≠ 0, the zero divisor graph ��(R) is a simple connected graph having vertex set as the set of nonzero zero divisors of R, where two vertices x and y are adjacent if and only if xy = 0. We find the signless Laplacian spectrum of the zero divisor graphs ��(ℤn) for various values of n. Also, we find signless Laplacian spectrum of ��(ℤn) for n = pz, z ≥ 2, in terms of signless Laplacian spectrum of its components and zeros of the characteristic polynomial of an auxiliary matrix. Further, we characterise n for which zero divisor graph ��(ℤn) are signless Laplacian integral.

• Communications of the Korean Mathematical Society
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• v.37 no.2
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• pp.551-566
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• 2022

We apply Fourier-Legendre-based integration methods that had been given by Campbell in 2021, to evaluate new rational double hypergeometric sums involving ${\frac{{1}}{\pi}}$. Closed-form evaluations for dilogarithmic expressions are key to our proofs of these results. The single sums obtained from our double series are either inevaluable $_2F_1({\frac{4}{5}})$- or $_2F_1({\frac{1}{2}})$-series, or Ramanujan's ₃F₂(1)-series for the moments of the complete elliptic integral K. Furthermore, we make use of Ramanujan's finite sum identity for the aforementioned ₃F₂(1)-family to construct creative new proofs of Landau's asymptotic formula for the Landau constants.

• Communications of the Korean Mathematical Society
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• v.38 no.1
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• pp.21-38
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• 2023

Let R be a commutative ring with identity. Let R be an integral domain and M a torsion-free R-module. We investigate the relation between the notion of e-exactness, recently introduced by Akray and Zebari [1], and generalized the concept of homology, and establish a relation between e-exact sequences and homology of modules. We modify some applications of e-exact sequences in homology and reprove some results of homology with e-exact sequences such as horseshoe lemma, long exact sequences, connecting homomorphisms and etc. Next, we generalize two special drived functor T or and Ext, and study some properties of them.

• Journal of Korean Society of Rural Planning
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• v.20 no.3
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• pp.191-199
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• 2014

The current rural conditions are undergoing the change from the past production-intensive structure to an integral and complex one of producing, processing, selling, touring and lodging owing to the changes of life-style, consumption trend and social environments. The rural area is developing into a community of rural tourism villages to grow into one management system along with the assistance of the government's various supporting projects. Through this, the rural designing has got to play a significant role as one of the factors of the enhancement of competitiveness and the increase of income. Therefore, those previous studies on the variety and possibility of rural development are being employed for the researches which are to develop techniques of branding, marketing and packaging. In particular, the researches for VI (Village Identity), BI (Brand Identity) and designs of landscaping, packaging of agricultural specialties and display stores, which definitely shows that the importance of rural designing, is being paid a lot more attention to. Thus, this study has verified the site commercialization and its effect by developing some practical designing with the focus of package design at rural tourism villages. The Okgye Village in Yoncheon was selected for study subject based on the result of status investigation. This study has analyzed such problems as lack of village identity, non-description of items and their indispensible marks which were seen their designs of village and packaging. The colors of major items and the village image being substituted into the image scale of IRI color were estimated so that the appropriate colors might be selected, along with which the shapes of major items were decided to be motif for the village symbol and design to be created. The designs of such major items as grains, greens and sauces were created with the consideration of the easiness of loading, the continuity of using and the aesthetics. For grains, those outer boxes which are possible for set-packaging and small-sized packaging have been developed. For greens were developed the boxes with the structure of the permeability for the persisten't quality as well as the possibility for packaging small amount. In case of sauces, those outer-boxes equipped with fixing tray were made with the transport-convenience taken into consideration. The sticker-label designs for all those three were also developed which stand for the village identity and are conveniently used in each farm family. When this development was applied at the sites, it was found that the satisfaction and reliability of consumers as well as the satisfaction of farmers were raised along with the increase by more than 30% after the improvement.