• Communications of the Korean Mathematical Society
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• v.36 no.3
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• pp.465-483
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• 2021

Let 𝓗(𝔻) be the space of analytic functions on the unit disc 𝔻. Let 𝜓 = (𝜓_j)ⁿ_j=0 and 𝚽 = (𝚽_j)ⁿ_j=0 be such that 𝜓_j, 𝚽_j ∈ 𝓗(𝔻). The linear differential operator is defined by T_𝜓(f) = ∑ⁿ_j=0 𝜓_jf^(j), f ∈ 𝓗(𝔻). We characterize the boundedness and compactness of the difference operator (T_𝜓 - T_𝚽)(f) = ∑ⁿ_j=0 (𝜓_j - 𝚽_j) f^(j) between weighted-type spaces of analytic functions. As applications, we obtained boundedness and compactness of the difference of multiplication operators between weighted-type and Bloch-type spaces. Also, we give examples of unbounded (non compact) differential operators such that their difference is bounded (compact).

• KIEAE Journal
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• v.16 no.5
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• pp.5-11
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• 2016

Purpose: Residents in deteriorated residential areas of Seoul have suffered from parking shortage problem. Since it is almost impossible to supply new parking, it is critical to find a way to efficiently utilize existing parking spaces. This study proposes utilizing unused parking spaces in apartment complexes so that residents in multi-unit or multi-family houses can share those parking spaces. Method: Spatial scope of this research is limited to multiplex-clustered neighborhood and apartment complex in Seoul. To identify the nature of parking problem, we reviewed current parking situations in residential areas and policies from the Seoul Metropolitan Government. To understand the amount of parking spaces required to solve parking shortages in multiplex-clustered neighborhoods, this study analyzed car ownership per household and available parking spaces in old residential areas. Then we were able to apprehend the amount of parking spaces that could be used for residents in aged multiplex-clustered areas. Result: Our analysis shows a great potential to utilize surplus parking spaces from apartment complexes for solving parking problems in multiplex-clustered neighborhoods.

• Journal of the Korean Mathematical Society
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• v.32 no.3
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• pp.583-591
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• 1995

Unless otherwise stated, we always assume that X is a Banach space, and $1 < p, q < \infty with \frac{p}{1}+\frac{q}{1} = 1$. We use S(X) and B(X) to denote the unit sphere and the unit ball in X respectively.

• Journal of Electrical Engineering and Technology
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• v.4 no.3
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• pp.323-329
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• 2009

This paper presents a new approach for thermal unit commitment (UC) using a differential evolution (DE) algorithm. DE is an effective, robust, and simple global optimization algorithm which only has a few control parameters and has been successfully applied to a wide range of optimization problems. However, the standard DE cannot be applied to binary optimization problems such as UC problems since it is restricted to continuous-valued spaces. This paper proposes binary differential evolution (BDE), which enables the DE to operate in binary spaces and applies the proposed BDE to UC problems. Furthermore, this paper includes heuristic-based constraint treatment techniques to deal with the minimum up/down time and spinning reserve constraints in UC problems. Since excessive spinning reserves can incur high operation costs, the unit de-commitment strategy is also introduced to improve the solution quality. To demonstrate the performance of the proposed BDE, it is applied to largescale power systems of up to 100-units with a 24-hour demand horizon.

• Journal of the Korean housing association
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• v.20 no.4
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• pp.19-29
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• 2009

The purpose of this study is to evaluate the air diffusion performance of a range of indoor units for room airconditioners; the wall-mounted type, floor-standing type, and ceiling-mounted type. These types of units, which have been widely used in housing spaces, will be studied with respect to thermal comfort and the energy performance using CFD analysis. In this study, current air conditioning status and related problems in housing spaces are examined, and a CFD analysis is performed in order to compare and analyze the thermal comfort and energy efficiency across each type of indoor-unit using the PMV, ADPI, EUC and FCEI indexes. The analysis results collectively considering thermal comfort and energy performance indicated that the ceiling-mounted type 4-way indoor unit showed the best diffusion performance in terms of thermal comfort, and had the second best diffusion performance in terms of energy performance after the wall-mounted type under certain conditions.

• Journal of The Korea Institute of Healthcare Architecture
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• v.7 no.2
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• pp.37-45
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• 2001

The hospice movement evolved as an alternative to hospitals as places to die. Recently, the palliative care for dying and hospice has been developed rapidly and placed itself as one of the medical systems. But the studies on hospice program and establishment method in Korea are few or no in comparison with developed countries. Hospice unit within a general hospital is more efficient hospice type than other terminal care establishments, therefor it will be developed rapidly. With this in mind, this study puts elements of architectural planning on the hospice unit for the space requirements. Also, It is investigated the architectural conditions of hospice unit within a general hospital, analyzed the unit space and spatial composition in hospice unit. The purpose of this study is to propose the fundamental data and unit space for architectural plan and design.

• Journal of the Korean Mathematical Society
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• v.41 no.6
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• pp.1035-1047
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• 2004

In this paper, we study the unit tangent sphere bundles T$_1$M(4c) of complex space forms M(4c) with constant holomorphic sectional curvature 4c. In particular, we determine T$_1$M(4c) whose Ricci tensors satisfy the Einstein-like conditions.

• Bulletin of the Korean Mathematical Society
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• v.52 no.4
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• pp.1383-1399
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• 2015

Let ${\mathbb{D}}=\{z{\in}{\mathbb{C}}:{\mid}z{\mid}<1\}$ be the open unit disk in the complex plane $\mathbb{C}$, ${\varphi}$ an analytic self-map of $\mathbb{D}$ and ${\psi}$ an analytic function in $\mathbb{D}$. Let D be the differentiation operator and $W_{{\varphi},{\psi}}$ the weighted composition operator. The boundedness and compactness of the product-type operator $W_{{\varphi},{\psi}}D$ from the weighted Bergman-Orlicz space to the weighted Zygmund space on $\mathbb{D}$ are characterized.

• Journal of the Korean Mathematical Society
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• v.41 no.1
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• pp.21-38
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• 2004

We prove that a Banach space that is convex-transitive and such that for some element u in the unit sphere, and for every subspace Μ containing u, it happens that the subset of norm attaining functionals on Μ is second Baire category in $M^{*}$ is, in fact, almost-transitive and superreflexive. We also obtain a characterization of finite-dimensional spaces in terms of functions that attain their supremum: a Banach space is finite-dimensional if, for every equivalent norm, every rank-one operator attains its numerical radius. Finally, we describe the subset of norm attaining functionals on a space isomorphic to $\ell$$_1$, where the norm is the restriction of a Luxembourg norm on $L_1$. In fact, the subset of norm attaining functionals for this norm coincides with the subset of norm attaining functionals for the usual norm.m.

• Journal of Korean Society of Rural Planning
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• v.22 no.3
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• pp.33-47
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• 2016

The purpose of this study is to understand the master plan of "The project on a comprehensive village development with a unit of a based township" through the master plan analysis and to help understand the implications of this project in order to maintain rural villages that can make local residents satisfied with them and promote the project of comprehensive rural village development as a successful way based on a comparative analysis through the in-site survey. The processes of this study are as follows. First, the analysis of development planning created a drawing based on linking business strategy by each region. The current situation and characteristics of planned public spaces were analyzed through the analysis of location and distribution of public spaces and facilities. Second, the situation analysis was performed by the task of shooting based on the basic plan information, and the master plan and status were confirmed through interviews. Also, the analysis of location and distribution of public spaces and facilities was conducted by a created drawings based on a survey. Finally, the detailed information of public spaces and facilities was compared with the investigation by in-site survey and analyzed through the Master Plan Strategy and a detailed classification of the types of facilities among each regional issues. In addition, by overlapping the planned drawings with the results, the results of formations were confirmed and the planned positional changes and the distribution of facilities were analyzed. As the results of "The project of comprehensive village development with a unit of based township", it was determined that there were many issues on cultural and welfare facilities in this project to meet the business objectives. Also, the facilities the residents needed, identified by interviews, were rural tourism facilities. According to the results, the residents cherished rural tourism facilities as much as basic living facilities. However, as the results of comparative analysis of public spaces and facilities, it was confirmed that mostly the plan was unfulfilled. Therefore, it is concluded that living, cultural and welfare facilities in the township can be maintained and expanded comprehensively as a purpose of "The project of comprehensive village development with a unit of based township" after not only planning process but also the project is fulfilled actually in rural areas.