• Journal of applied mathematics & informatics
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• v.25 no.1_2
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• pp.425-434
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• 2007

We iteratively generate a sequence of measurable mappings and study necessary conditions for its convergence to a random fixed point of random nonexpansive operator. A random fixed point theorem for random nonexpansive operator, relaxing the convexity condition on the underlying space, is also proved. As an application, we obtained random fixed point theorems for Caristi type random operators.

• Journal of information and communication convergence engineering
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• v.4 no.4
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• pp.136-140
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• 2006

In this paper, we consider the detection of orthogonal space-time block codes (OSTBCs) without channel state information (CSI) at the receiver. Based on the conventional blind cyclic decoder, we propose an enhanced blind cyclic decoder which has higher system performance than the conventional one. Furthermore, the proposed decoder offers low complexity since it does not require the computation of singular value decomposition.

• Bulletin of the Korean Mathematical Society
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• v.36 no.4
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• pp.717-722
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• 1999

The set of continuous maps of a space X to real usual space R equipped with the toplogy of pointwise convergence will be denoted by $C_p$(X). In this paper, we prove that; $C_p$(X) is hereditarily separable and hereditary Lindelof if and only if $X^n$ is hereditarily separable and hereditary Lindelof.

• Bulletin of the Korean Mathematical Society
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• v.38 no.2
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• pp.285-292
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• 2001

The authors compute the Ricci curvature of the GRW space-time to obtain two conditions for the conjugate points which appear as the Timelike Convergence Condition(TCG) and the Jacobi inequality. Moreover, under such two conditions, we obtain a lower bound of the length of a unit timelike geodesic for focal points emanating form the immersed spacelike hypersurface, the graph over the fiber in the GRW space-time.

• Bulletin of the Korean Mathematical Society
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• v.38 no.2
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• pp.293-302
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• 2001

We improve the greedy algorithm which is one of the general convergence criterion for certain iterative sequence in a given space by building a constructive greedy algorithm on a normed linear space using an arithmetic average of elements. We also show the degree of approximation order is still $Ο(1\sqrt{\n}$) by a bounded linear functional defined on a bounded subset of a normed linear space which offers a good approximation method for neural networks.

• Journal of the Korea Convergence Society
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• v.8 no.6
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• pp.227-235
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• 2017

The essence of architecture is space acquired as a result of architect's design act, but the object of the design is not the space and it is the physical elements to construct it. The masters of modern architecture have described the types of spaces that can be composed of these elements, but there is a difficulty in constructing the space because they does not mention how to construct it. From this point of view, if architecture is the techniques for human behavior and the art of building space, it is recognized that there is a need for concrete research on how to construct a space with ambiguous substance. Therefore, I conducted research on the extensibility of diagonal spaces through '4 Logements Studio' by Henri Ciriani, a representative architect of Neo Corbusian. The 'network for identity' method proposed by Ciriani was examined as a methode to realize spatial expansion and the furniture should be designed as an element of reading space and 3 optimal alternatives for 4 housing arrangements were obtained based on the Equivalence, Lighting, View, and Community life.

• Journal of the Korea Convergence Society
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• v.12 no.8
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• pp.145-155
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• 2021

With the massive expansion of cities in the 20th century, many fragmented small spaces are emerged. This research establishes a framework for analysis based on forward theories, and takes the development of small spaces in Busan as an example, draws conclusions through analysis, and construct a design model for the effective use of small spaces. Based on the theory of spatial design research, statistical analysis methods are used to analyse the effective use of fragmented small spaces in city. In order to provide guidance and reference suggestions when analyzing and researching this type of space design on the data collected from the survey in the future. The design of small spaces is a way to improve the efficiency of the space utilization through the reasonable design of this type of spaces. Urban space is designed to meet the requirements of urban residents as well as to consider the sustainable development of the environment and resources, society and culture. Meaningful solutions are proposed for the construction and development of the sustainable of the future urban spaces.

• International journal of advanced smart convergence
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• v.9 no.4
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• pp.52-61
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• 2020

The AHP method was used in 30 provinces of China to construct the index system of creative space efficiency evaluation and determine the weight of each index. The fuzzy comprehensive evaluation method was further used to score the indexes at all levels, and then the total efficiency score was sorted. The purpose of this study is to adjust the regional layout of creative space reasonably and implement financial policies accurately through the evaluation of the efficiency of creative space. The results is ranking top in weight of several indicators, which include the number of incubated Startups, the number of innovation and entrepreneurship mentors, the survival rate of incubator, the innovative training activities, etc. It was also found that Beijing, Shanghai, Jiangsu, Guangdong and Zhejiang ranked first in the score of creative space efficiency. This study is meaningful in that it was In order to effectively solve the problem of the imbalance of the creative space efficiency in China's province, by coordinating the regional pattern, establishing a sound service system and improving the efficiency evaluation system.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.5
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• pp.430-436
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• 2014

The mission objective of STEP Cube Lab. (Cube Laboratory for Space Technology Experimental Project) classified as a pico-class satellite is to verify the technical effectiveness of payloads such as variable emittance radiator, SMA washer, oscillating heat pipe and MEMS based solid propellant thruster researched at domestic universities. In addition, the MEMS concentrating photovoltaic power system and the non-explosive holding and separation mechanism with the advantages of high constraint force and low shock level will be developed as the primary payloads for on-orbit verification. In this study, the feasibility of the mission actualization has been confirmed by the preliminary system design.

• Communications of the Korean Mathematical Society
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• v.33 no.2
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• pp.677-693
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• 2018

In this work, we generalize a family of optimal eighth order weighted-Newton methods to Banach spaces and study its local convergence to approximate a locally-unique solution of a system of nonlinear equations. The convergence in this study is shown under hypotheses only on the first derivative. Our analysis avoids the usual Taylor expansions requiring higher order derivatives but uses generalized Lipschitz-type conditions only on the first derivative. Moreover, our new approach provides computable radius of convergence as well as error bounds on the distances involved and estimates on the uniqueness of the solution based on some functions appearing in these generalized conditions. Such estimates are not provided in the approaches using Taylor expansions of higher order derivatives which may not exist or may be very expensive or impossible to compute. The convergence order is computed using computational order of convergence or approximate computational order of convergence which do not require usage of higher derivatives. This technique can be applied to any iterative method using Taylor expansions involving high order derivatives. The study of the local convergence based on Lipschitz constants is important because it provides the degree of difficulty for choosing initial points. In this sense the applicability of the method is expanded. Finally, numerical examples are provided to verify the theoretical results and to show the convergence behavior.