• BMB Reports
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• v.35 no.1
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• pp.94-105
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• 2002

Apoptotic cell death is a fundamental and highly regulated biological process in which a cell is instructed to actively participate in its own demise. This process of cellular suicide is activated by developmental and environmental cues and normally plays an essential role in eliminating superfluous, damaged, and senescent cells of many tissue types. In recent years, a number of experimental studies have provided evidence of widespread neuronal and glial apoptosis following injury to the central nervous system (CNS). These studies indicate that injury-induced apoptosis can be detected from hours to days following injury and may contribute to neurological dysfunction. Given these findings, understanding the biochemical signaling events controlling apoptosis is a first step towards developing therapeutic agents that target this cell death process. This review will focus on molecular cell death pathways that are responsible for generating the apoptotic phenotype. It will also summarize what is currently known about the apoptotic signals that are activated in the injured CNS, and what potential strategies might be pursued to reduce this cell death process as a means to promote functional recovery.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.2 no.3
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• pp.101-107
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• 1982

The progressive sampling method adapts well to the local variabilities of the input terrains, and is therefore one of the most efficient sampling methods in DTM. The efficiency of progressive sampling can be enhanced by increasing the comprehensiveness of grid densification criteria, with superfluous points reduced and/or suppressed. In this investigation, four different criteria were applied to the numerical test, and the suppression criterion was found the most significant among them.

• Korean Journal of Computational Design and Engineering
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• v.7 no.3
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• pp.170-176
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• 2002

To exchange CAD data between heterogeneous CAD systems, we generally use a neutral format especially STEP, which is the international standard (ISO-10303) for product model data exchange. AP214 (Application Protocol) for the automotive industry not only takes into account geometry and organizational data, but also provides a classification mechanism for product modeling. When reading a STEP file during a design process that is exported from other CAD systems, it is a burden to a designer to go through the tedious process of removing duplicate or non-manifold entities, adjusting parts, and rearranging text. We analyze the structure of AP214 and develop a healing tool to solve the following problem. Without the assembly information in the Master workspace of CATIA, or to read a STEP file from Pro/Engineer, a designer should do a repetitive process of disintegrating an assembly into parts one by one. We have developed a post-processing tool for STEP AP214 that separates out a part from an assembly model and adjusts superfluous or useless entities using the ACIS kernel.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.11a
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• pp.107-108
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• 2017

The purpose of this study is to derive the optimum water absorbing curing time. It was found that the cement paste compressive strength was increased with the water absorbing ratio up to 40%, but the compressive strength was slightly lower when the catch level was over 50%. It is considered that the superfluous water did not react and remained in the inside of the specimen, causing microcracks in the inside due to the high temperature curing, resulting in a decrease in strength. Therefore, it is considered that the optimum catcher curing time for improving the strength through catcher curing is when the catcher reaches 40%.

• Communications of the Korean Mathematical Society
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• v.15 no.3
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• pp.453-467
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• 2000

For any S-flat module RM(which will be called endoflat) with a commutaitve ring R with identity, where S is the endomorphism ring RM, the fact that every epimorphism is an automorphism has been proved and the Jacobson Radical Rad(S) of S is described as follow; Rad(S) = { f$\in$S｜Imf=Mf is small in M} = {f$\in$S｜Imf $\leq$Rad(M)}. Additionally for any quasi-injective endo-flat module RM, the fact that every monomorphism is an automorphism has been proved and the Jacobson Radical Rad(S) for any quasi-injective endo-flat module has been studied too. Also some equivalent conditions for the semi-primitivity of any faithful endo-flat module RM with the open Jacobson Radical Rad(M) and those for the semi-simplicity of any faithful endo-flat quasi-injective module RM with the closed Socle Soc(M) have been studied.

• Communications of the Korean Mathematical Society
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• v.25 no.3
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• pp.327-333
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• 2010

Let R be a 2-torsion free prime ring, U a nonzero Lie ideal of R such that $u^2\;{\in}\;U$ for all $u\;{\in}\;U$. In the present paper, it is proved that if d is a nonzero derivation and [[d(u), u], u] = 0 for all $u\;{\in}\;U$, then $U\;{\subseteq}\;Z(R)$. Moreover, suppose that $d_1$, $d_2$, $d_3$ are nonzero derivations of R such that $d_3(y)d_1(x)\;=\;d_2(x)d_3(y)$ for all x, $y\;{\in}\;U$, then $U\;{\subseteq}\;Z(R)$. Finally, some examples are given to demonstrate that the restrictions imposed on the hypothesis of the above results are not superfluous.

• Communications of the Korean Mathematical Society
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• v.36 no.2
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• pp.229-238
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• 2021

Let R be a ring with characteristic different from 2. An additive mapping F : R → R is called a generalized derivation on R if there exists a derivation d : R → R such that F(xy) = F(x)y + xd(y) holds for all x, y ∈ R. In the present paper, we show that if R is a prime ring satisfying certain identities involving a generalized derivation F associated with a derivation d, then R becomes commutative and in some cases d comes out to be zero (i.e., F becomes a left centralizer). We provide some counter examples to justify that the restrictions imposed in the hypotheses of our theorems are not superfluous.

• Communications of the Korean Mathematical Society
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• v.37 no.2
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• pp.359-370
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• 2022

The principal aim of this paper is to study the connection between the structure of a quotient ring R/P and the behavior of special additive mappings of R. More precisely, we characterize the commutativity of R/P using derivations (generalized derivations) of R satisfying algebraic identities involving the prime ideal P. Furthermore, we provide examples to show that the various restrictions imposed in the hypothesis of our theorems are not superfluous.

• Kyungpook Mathematical Journal
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• v.62 no.1
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• pp.43-55
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• 2022

Let R be a *-ring and n ≥ 1 be an integer. The objective of this paper is to introduce the notion of n-skew centralizing maps on *-rings, and investigate the impact of these maps. In particular, we describe the structure of prime rings with involution '*' such that _*[x, d(x)]_n ∈ Z(R) for all x ∈ R (for n = 1, 2), where d : R → R is a nonzero derivation of R. Among other related results, we also provide two examples to prove that the assumed restrictions on our main results are not superfluous.

• Journal of Korean Neurosurgical Society
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• v.65 no.3
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• pp.361-369
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• 2022

Pediatric spine has growth potential with incomplete ossification, and also unique biomechanics which have important implications for trauma patients. This article intends to review various aspects of pediatric spine trauma including epidemiology, anatomy and biomechanics, and clinically relevant details of each type of injury based on the location and mechanism of injury. With the appropriate but not superfluous treatment, pediatric spine trauma patients can have better chance of recovery. Therefore, as a spine surgeon, understanding the general concept for each injury subtype together with the debate and progress in the field is inevitable.