• Proceedings of the KSR Conference
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• 2004.06a
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• pp.915-920
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• 2004

We have studied the technologies for a double-deck train. But, there are no standards and test methods for a double-deck train. Therefore, we apply the standard and test method of the general train to transform the structural analysis of a double-deck train. This study is the result of a structural analysis by the finite element method for double-deck train carbodies. The results of the study can be used as basic guidelines in designing double-deck trains in the future.

• Kyungpook Mathematical Journal
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• v.54 no.1
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• pp.143-153
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• 2014

The notion of double-framed soft filters of a CI-algebra is introduced, and related properties are investigated. Further characterization of a double-framed soft filter is considered, and conditions for a double-framed soft set to be a double-framed soft filter are provided. Finally a new double-framed soft filter from old one is established.

• Journal of the Chungcheong Mathematical Society
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• v.30 no.1
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• pp.1-13
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• 2017

We introduce the concepts of (${\mathcal{T}}^{{\mu}{\gamma}},{\mathcal{U}}^{{\mu}{\gamma}}$)-double (r, s)(u, v)-preclosures and (${\mathcal{T}}^{{\mu}{\gamma}},{\mathcal{U}}^{{\mu}{\gamma}}$)-double (r, s)(u, v)-preinteriors. Using the notions, we investigate some of characteristic properties of double pairwise (r, s)(u, v)-precontinuous mappings.

• Communications for Statistical Applications and Methods
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• v.16 no.5
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• pp.859-870
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• 2009

We obtain a skewed double Weibull distribution by a double Weibull distribution, and evaluate its coefficient of skewness. And we obtain the approximate maximum likelihood estimator(AML) and moment estimator of skew parameter in the skewed double Weibull distribution, and hence compare simulated mean squared errors(MSE) of those estimators. We compare simulated MSE of two proposed reliability estimators in two independent skewed double Weibull distributions each with different skew parameters. Finally we introduce a skewed double Weibull distribution generated by a uniform kernel.

• Journal of the Chungcheong Mathematical Society
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• v.30 no.4
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• pp.423-433
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• 2017

We introduce the concepts of double strongly (r, s)(u, v)-semiopen sets, double strongly (r, s)(u, v)-semiclosed sets and double pairwise strongly (r, s)(u, v)-semicontinuous mappings in double bitopological spaces and investigate some of their characteristic properties.

• Bulletin of the Korean Mathematical Society
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• v.60 no.2
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• pp.443-460
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• 2023

A binary linear code is said to be a ℤ₂-double cyclic code if its coordinates can be partitioned into two subsets such that any simultaneous cyclic shift of the coordinates of the subsets leaves the code invariant. These codes were introduced in [6]. A ℤ₂-double cyclic code is called reversible if reversing the order of the coordinates of the two subsets leaves the code invariant. In this note, we give necessary and sufficient conditions for a ℤ₂-double cyclic code to be reversible. We also give a relation between reversible ℤ₂-double cyclic code and LCD ℤ₂-double cyclic code for the separable case and we present a few examples to show that such a relation doesn't hold in the non-separable case. Furthermore, we list examples of reversible ℤ₂-double cyclic codes of length ≤ 10.

• The Journal of Korean Academy of Prosthodontics
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• v.44 no.6
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• pp.677-682
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• 2006

Statement of problem. Various double crown systems have been used with removable partial dentures in the clinical field. Although retentive force between inner and outer crown are affected by several factors, differences between the retentive forces of different double crown system types are expected. Purpose. The purpose of this study was to evaluate the initial retentive force of outer crowns fabricated by the conventional casting technique in conus and hybrid double crowns. Material and methods. Ten double crowns were fabricated. The groups were as follows. Group 1, double crowns of hybrid inner and outer crowns using the conventional casting method; Group 2, double crowns of conus inner and outer crowns using the conventional casting method. Tensile strengths of double crowns when the inner and outer crowns were separated on a universal testing machine were measured. These values of retentive force were then statistically analyzed using the Kruskal-Wallis test. Results. Retentive force in group 2 was significantly higher than that in group 1(p<.05). Conclusion. The initial retentive forces of double crowns were affected by the types of the double crown system.

• Journal of the Korean Home Economics Association
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• v.44 no.6 s.220
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• pp.47-58
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• 2006

This research focused on the family stress and family strengths in double-income couples. The subjects of this study were 171 double-income couples, in the Kyeongnam Area, Korea. The major findings from the study are as follows. 1) The degree of family stress of the husband and wife in double-income couples was 2.90 and 2.97, respectively, on a scale of 0-5.0. The significant variables were economic level, self-esteem and marital satisfaction in double-income couples' husband, and having a housework-helper, job satisfaction, self-esteem and marital satisfaction in double-income couples' wife. 2) The degree of family strengths of the husband and wife in double-income couples was 3.84 and 3.82, respectively, on a scale of 0-5.0. The significant variables were job satisfaction, self-esteem and marital satisfaction in double-income couples' husband, and the educational level, job type, self-esteem and marital satisfaction in double-income couples' wife. 3) There was a close inverse correlation between the lamely stress and family strengths in the husband and wife of double-income couples.

• Special Issue of the Society of Naval Architects of Korea
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• 2013.12a
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• pp.81-84
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• 2013

일반적인 Bulk carrier는 Single deck, Double bottom, Hopper side tank, Top side tank와 함께 Single side skin 또는 Double side skin으로 구성되어 Single hull bulk carrier 또는 Double hull bulk carrier라 불린다. 본 논문의 연구선박인 Double hull bulk carrier는 CSR에서 규정짓고 있는 Double hull bulk carrier의 특징 중 Hopper side tank가 없기에 일반적인 Double hull bulk carrier와는 다른 구조를 가진다. 구조적 특징으로는 Inner bottom과 Inner hull 연결부위에 응력 집중 발생, Side shell의 Shear에 대해 구조적 안전성, Double hull에 대한 CSR for bulk carrier의 Rule적용 여부에 대한 판단 등이 있다. 따라서 본 연구에서는 Double hull bulk carrier의 구조적 특징과 구조해석을 통한 응력 집중 부위의 평가 및 Fatigue analysis을 통한 피로수명을 계산하여 이를 통해 구조의 안전성을 살펴보고자 한다.

• Journal of the Chungcheong Mathematical Society
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• v.32 no.3
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• pp.309-318
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• 2019

We introduce the concepts of double pairwise strongly (r, s)(u, v)-semiopen mappings and double pairwise strongly (r, s)(u, v)-semiclosed mappings, and investigate some of their characteristic properties.