• Bulletin of the Korean Mathematical Society
• /
• v.44 no.4
• /
• pp.683-689
• /
• 2007

Let $\mathcal{B}$ be a certain Banach space consisting of analytic functions defined on a bounded domain G in the complex plane. Let ${\varphi}$ be an analytic polynomial or a rational function and let $M_{\varphi}$ denote the operator of multiplication by ${\varphi}$. Under certain condition on ${\varphi}$ and G, we characterize the commutant of $M_{\varphi}$ that is the set of all bounded operators T such that $TM_{\varphi}=M_{\varphi}T$. We show that $T=M_{\Psi}$, for some function ${\Psi}$ in $\mathcal{B}$.

• Wind and Structures
• /
• v.15 no.5
• /
• pp.441-462
• /
• 2012

This article presents theoretical investigations on techniques for the improvement of the dynamic characteristics of slender bridges under wind action. Aerodynamically effective control shields are applied as controlled actuators. The first part of the article describes the modelling of the uncontrolled aeroelastic system. Acting aerodynamic forces are consistently characterised using linear time-invariant transfer elements in terms of rational functions. On this basis, two configuration levels of the uncontrolled system are represented with linear time-invariant state-space models and investigated. The second part of the article addresses controller design and the behaviour of the controlled aeroelastic system. Both fundamental limits for stabilisation and the efficiency for attenuating the influence of gusts are described for different actuator mechanisms. The results are derived and discussed with methods of control theory.

• Journal of Institute of Control, Robotics and Systems
• /
• v.4 no.3
• /
• pp.301-307
• /
• 1998

이 논문에서는 다항식 서로소 인수로 표시되는 위너-호프 제어기의 계산상의 어려움을 극복하기 위하여 상태공간 변수 공식이 개발되었다. 위너-호프 인수 행렬을 이용하여 주어진 다항식 서로소 인수로부터 안정 유리행렬의 서로소 인수를 구하였으며 이 결과를 이용하여 위너-호프 제어기의 공식을 유리행렬의 서로소 인수로 표현한 후 이를 이용하여 상태공간 계수를 구하였다.

• Korean Institute of Interior Design Journal
• /
• no.8
• /
• pp.16-22
• /
• 1996

In terms of modern design history, De Stijl movement had continued as one of influential groups by 1931, and it attempted to pursue universial reality that combined painting and architecture, seeking a new style based on Neo-Plasticism and succeeded the nineteen century's Art and Craft movement and Art Nouveau. Especially, the De Stijl movement provided 1920's rationalism with new space pattern and its ideas greatly affected the Bauhaus movement such as Walter Gropius or Mies van der Rohe. De Stijl's utopian idea that claimed on the conformity of art and life contributed modernism movement combined with scientific and rational view, and even now experts its lasting power with the concept of time and space free from simple cube in modern architecture and interior design. The tue meaning of the De Stijl movements is that is sis the basis of general ideas, and the change of modern architecture is based on this modern styled foundation. It may be the unchangeable fact like Russell Hitchocok says, "The architectural style and pattern which everyone admitts its importance has the value of living."

• Communications of the Korean Mathematical Society
• /
• v.34 no.3
• /
• pp.991-1004
• /
• 2019

Firstly we consider preorders (not necessarily partial orders) on a canonical quotient of the set of the homotopy classes of continuous maps between two spaces induced by a certain equivalence relation ${\sim}_{{\varepsilon}R}$. Secondly we apply it to a classification of orientable fibrations over Y with fibre X. In the classification theorem of J. Stasheff [22] and G. Allaud [3], they use the set $[Y,\;Baut_1X]$ of homotopy classes of continuous maps from Y to $Baut_1X$, which is the classifying space for fibrations with fibre X due to A. Dold and R. Lashof [11]. In this paper we give a classification of fibrations using a preordered set (abbr., proset) structure induced by $[Y,\;Baut_1X]_{{\varepsilon}R}:=[Y,\;Baut_1X]/{\sim}_{{\varepsilon}R}$.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.46 no.2
• /
• pp.106-113
• /
• 2018

The Intense acoustic wave generated by the jet flame at the lift-off causes the vehicle to vibrate in the form of acoustic loads. The DSM-II(Distributing Source Method-II), which is a representative empirical acoustic loads prediction method, is a method of distributing a noise source along a jet flame axis and has advantages in calculation cost and accuracy. However, due to the limitation of the distributing method, there is a limit to accurately reflect the various launch pad configurations. In this study, acoustic loads prediction method which can freely distribute noise sources is studied. by introducing NURBS(Non-Uniform Rational B-Spline) modeling into empirical prediction method. For the verification of the newly introduced analytical technique of the NURBS, the acoustic loads prediction for the Epsilon rocket's low-noise launch pad shape was performed and the results of the analysis were compared with the existing prediction methods and experimental results.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.3 no.2
• /
• pp.13-22
• /
• 2001

In this study, numerical analyses on cut-and-cover tunnel linings were performed using different modeling methods based on both structural and geotechnical engineering. The purpose was to find a relatively more reasonable modeling method and boundary conditions. The results of the study revealed problems associated with each modeling method and factors influencing the behavior of cut-and-cover tunnel lining. A method was proposed allowing the simulation of field condition in a more rational way. It was indicated that, under the given conditions, displacements and member forces occurring on concrete lining could be different as much as 53% depending on the type of modeling method applied; and 32% depending on the boundary conditions employed. Determination of boundary conditions properly simulating actual field conditions and verification of prediction based on instrumentation are essential for rational design and analysis.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.25 no.6
• /
• pp.1057-1068
• /
• 2001

The purpose of this study was to clarify service quality of apparel stores and find out related variables. The related variables are contained customer's characteristics (shopping orientation, demographic characteristics), store types and store patronage behavior in apparel store. The subjects selected for the final analysis were 363 females aged from 20 to 59 who lived in Taejon. And the data were collected using a questionnaire and analyzed through factor analysis, ANOVA, cluster analysis, regression, Duncan test, Tukey test. The results of this study were as follows; 1. Services quality of apparel stores consisted of seven dimensions ; ability of salesperson, belief in policy, convenience of facility, attractiveness of physical environment, convenience of using credit cards, convenience of space movement. and apparence of salespeople. 2. Shopping orientation consisted of four dimensions; recreational shopping orientation, rational shopping orientation. convenience-oriented shopping orientation, price-conscious shopping orientation. Shopper types consisted of three dimensions ; recreational-economical type shopper, rational type shopper, convenience-oriented type shopper. Significant relationships were found out between those shopper types and service quality. Significant difference was caused by demographic characteristics(age, marital status, education, income. job) except for places of residence and service quality. 3. The significant difference was found out between store types and service quality. 4. Service quality(ability of salespeople. belief in policy, convenience of facility, convenience of using credit cards. apparence of salespeople) were influenced store patronage behavior.

• Journal of The Korea Institute of Healthcare Architecture
• /
• v.26 no.1
• /
• pp.51-62
• /
• 2020

Purpose: The Intensive Care Unit (ICU) is an important inpatient care area where critical patients are treated intensively with advanced medical technology. The level of care of ICU and the modernization of related facilities is an important indicator of health care quality. At the present time, when the Regional public hospitals are frequently expanding, the rational planning of the ICU has become an important part of the medical institutions treating the ICU. The purpose of this study is to present basic data with net area which can be used in the architectural planning of the ICU. Methods: The investigation and analysis of the ICUs were conducted on 26 medical facilities, based on theoretical analysis through relevant guidelines, articles, and documents, and on the basis of the actual space composition and net area analysis through the architectural drawings. Results: This study provides basic data such as zone division, spatial composition, relationship between main activities and zones, composition of facilities in the zone and area ratio within each zone. Implications: The results of this paper are expected to be effective reference materials for future research for rational spatial organization and efficient operation of the Intensive Care Unit in regional public hospitals.

• Journal of The Korea Institute of Healthcare Architecture
• /
• v.25 no.3
• /
• pp.37-46
• /
• 2019

Purpose: The Intensive Care Unit (ICU) is an important inpatient care area where critical patients are treated intensively with advanced medical technology. The level of care of ICU and the modernization of related facilities is an important indicator of health care quality. At the present time, when the Regional public hospitals are frequently expanding, the rational planning of the ICU has become an important part of the medical institutions treating the ICU. The purpose of this study is to present basic data with net area which can be used in the architectural planning of the ICU. Methods: The investigation and analysis of the ICUs were conducted on 24 medical facilities, based on theoretical analysis through relevant guidelines, articles, and documents, and on the basis of the actual space composition and net area analysis through the architectural drawings. Results: This study provides basic data such as bed placement type of ICU, relationship with other departments, distance between NS and bed, distance between beds, and net area of disease by type. Implications: The results of this paper are expected to be effective reference materials for future research for rational spatial organization and efficient operation of the Intensive Care Unit in regional public hospitals.