• Title/Summary/Keyword: free spaces

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SPLITTINGS FOR THE BRAID-PERMUTATION GROUP

  • Jeong, Chan-Seok;Song, Yong-Jin
    • Journal of the Korean Mathematical Society
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    • v.40 no.2
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    • pp.179-193
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    • 2003
  • The braid-permutation group is a group of welded braids which is the extension of Artin's braid groups by the symmetric groups. It is also described as a subgroup of the automorphism group of a free group. We also show that the plus-construction of the classifying space of the infinite braid-permutation group has the following two types of splittings BBP(equation omitted) B∑(equation omitted) $\times$ X, BBP(equation omitted) B $^{+}$$\times$ Y=S$^1$$\times$Y, where X, Y are some spaces.

Acoustic characteristics of sound field in partially opened rooms - Emphasis on horizontal coupling of diffuse and non-diffuse field - (실내공간의 부분적 개방에 따른 음향특성변화 I - 확산음장과 자유음장의 수평적 결합을 중심으로 -)

  • Jeong, Dae-Up;Choi, Young-Ji;Kim, Ji-Young;Oh, Yang-Ki;Choi, Seok-Ju
    • Journal of Korean Association for Spatial Structures
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    • v.7 no.2 s.24
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    • pp.105-114
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    • 2007
  • Large span spaces have been widely used for various purposes including sports events in other countries. Due to increasing demands on multi-purpose use of such spaces, recently built large span sport facilities such dome stadiums have been required to accommodate sport events as well as performing events. Also, retractable ceilings and/or walls were generally adopted in those spaces for providing various event conditions. It seems obvious that the openings between diffuse fields and free field may cause difficulties in the acoustic design of such spaces In the present work, the acoustic characteristics of non-diffuse field has been investigated using 1/10 acoustic scale models. It was found that RTs at low- and mid-frequencies decayed faster than those at high-frequencies as the percentage of opening area increased. The decay rate of RTs at high frequencies were not influenced by increasing the area of an opening. Also high dependence of EDT on the percentage of opening area was observed at all frequency range. D50 was not improved by increasing the area of an opening up to 12.5% and then sharply increased. The application of Schroeder integration to evaluate the reverberation charateristics of coupled spaces may not be proper, since non-exponential decay process with double or triple decays of those spaces can not be properly defined. EDT seems more appropriate to predict reverberation at the early acoustic design stage of acoustically coupled spaces.

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A Study on the Characteristics and Satisfaction on the Interior Design of Asian Cruise Ship - Focused on the interior space of Costa Victoria - (한·중·일 크루즈 선박 실내디자인 특성 및 만족도 연구 - 코스타 빅토리아호의 실내공간을 중심으로 -)

  • Bong, Sunwha;Yoon, Jiyoung
    • Korean Institute of Interior Design Journal
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    • v.22 no.1
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    • pp.328-338
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    • 2013
  • This study aims at exploring the characteristics of interior design of the Cruise line running Korea, Japan and China, and the satisfaction level of the Korean passengers for the interior design. Literature review and the physical traces of the cruise ship interior including 4 types of cabins and public spaces such as main hall, restaurants, outdoor swimming pool, jogging track, theater, meeting room, duty-free shop were performed. Also, the questionnaire to the passengers were used to understand their preferences and satisfaction level for each space. The results show that the passengers are very satisfied with the color and atmosphere of the cabin, while they complain the inconvenience of the bathroom size. Also in the public space, they prefer western classic style and modern style rather than Asian or Korean style. This means that they want the exotic feeling coming out of home. Also they prefer buffet restaurant, duty-free shop, theater, observation platform compared to other public spaces. However, the problem is that there are no place for the Korean family members with young children except for the outdoor pool. The interior and the program should be redesigned for the public spacs such as cinema room, family karaoke and internet-free room for Korean passengers.

SAF: A Scheme of Swap Space Allocation in File Systems to Reduce Disk Seek Time (SAF: 디스크 탐색 시간 향상을 위한 파일 시스템 내 스왑 공간 할당 기법)

  • Ahn, Woo-Hyun;Kim, Bo-Gon;Kim, Byung-Gyu;Oh, Jae-Won
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.15 no.6
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    • pp.1289-1300
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    • 2011
  • In recent computer systems with high-performance, users execute programs needing large memory and programs intensively accessing files simultaneously. Such a large memory requirement makes virtual memory systems access swap spaces in disk, and intensive file accesses require file systems to access file system partitions in disk. Executing the two kinds of programs at once incurs large disk seeks between swap spaces and file system partitions frequently. To solve the problem, this paper proposes a new scheme called SAF to create several swap spaces in a file system partition, where pages to be paged out are stored. When a page is paged out, the scheme stores the page to one of the swap spaces close to a disk location where the most recently accessed file is located. The chosen swap space in the file system partition is closer to the disk location than the traditional swap space, so that our scheme can reduce the large disk seek time spent to move to the traditional swap space in paging out a page. The experiment of our scheme implemented in FreeBSD 6.2 shows that SAF reduces the execution time of several benchmarks over FreeBSD ranging from 14% to 42%.

Second-Hand Smoke in Public Spaces: How Effective has Partial Smoke-Free Legislation Been in Malaysia?

  • Abidin, Emilia Zainal;Hashim, Zailina;Semple, Sean
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.11
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    • pp.6845-6850
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    • 2013
  • Background: This study was performed to gather data on second-hand smoke (SHS) concentrations in a range of public venues following the implementation of partial Smoke-Free Legislation in Malaysia in 2004. Materials and Methods: $PM_{2.5}$ was measured as a marker of SHS levels in a total of 61 restaurants, entertainment centres, internet caf$\acute{e}$s and pubs in Kuala Lumpur, Malaysia. Results: Under the current smoke-free laws smoking was prohibited in 42 of the 61 premises. Active smoking was observed in nearly one-third (n=12) of these. For premises where smoking was prohibited and no active smoking observed, the mean (standard deviation) indoor $PM_{2.5}$ concentration was 33.4 (23.8) ${\mu}g/m^3$ compared to 187.1 (135.1) ${\mu}g/m^3$ in premises where smoking was observed The highest mean $PM_{2.5}$ was observed in pubs [361.5 (199.3) ${\mu}g/m^3$]. Conclusions: This study provides evidence of high levels of SHS across a range of hospitality venues, including about one-third of those where smoking is prohibited, despite 8 years of smoke-free legislation. Compliance with the legislation appeared to be particularly poor in entertainment centres and internet caf$\acute{e}$s. Workers and non-smoking patrons continue to be exposed to high concentrations of SHS within the hospitality industry in Malaysia and there is an urgent need for increased enforcement of existing legislation and consideration of more comprehensive laws to protect health.

Studios on the Physical and Psychological Analysis in Street Spaces for Improving the Streetscape of Olympic Daero (올림픽대로의 경관향상을 위한 가로공간 구성요소의 물리량과 심리량 분석에 관한 연구)

  • 김광래;진희성
    • Journal of the Korean Institute of Landscape Architecture
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    • v.16 no.2
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    • pp.23-41
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    • 1988
  • Environmental design pattern of the nine Small Urban Spaces at C.B.D. in City of Seoul are surveyed and analyzed for user's satisfaction and behavior under the environmental design evaluation by using Chrisopher Alexander's Pattern Language. Small Urban Spaces as a part of streetscape are formed by physical factors as well as visual environment and interacting user's behavior. Therefore, user's satisfacuion and behavior at the nine Urban Small Spaces were investigated under the further search for some possibilities of a pplication of those Pattern Languages. A pattern language has a structure of a network. It is used in sequence, going through the patterns, moving always from large patterns to smaller, always from the ones which create comes simply from the obsernation that most of the wonderful places of the city were not made by architects but by the people. It defines the limited number of arrangements of spaces that make sense in any given culture. And it actually gives us the power to generate these coherent arrangement of space. As a results, 'Plazl', 'Seats' and 'Accessibility' related design patterns are highly evaluated by Pattern Frequency, Pattern Interaction and their Composition ranks, thus reconfirm Whyte's Praise of urban Small Spaces in our inner city design environments. According to the multiple regression analysis of user's evaluation, the environmental functins related to the satisfaction were 'Plaza', 'Accessibility' and 'Paving'. According to the free response, user's prefer such visually pleasing environmental design object as 'Waterscape' and 'Setting'. In addition to, the basic needs in Urban Small Spaces are amenity facilities as bench, drinking water and shade for rest.

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GROUPS ACTING ON MEDIAN GRAPHS AND MEDIAN COMPLEXES

  • Ryang, Dohyoung
    • The Pure and Applied Mathematics
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    • v.19 no.4
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    • pp.349-361
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    • 2012
  • CAT(0) cubical complexes are a key to formulate geodesic spaces with nonpositive curvatures. The paper discusses the median structure of CAT90) cubical complexes. Especially, the underlying graph of a CAT(0) cubical complex is a median graph. Using the idea of median structure, this paper shows that groups acting on median complexes L(${\delta}$) groups and, in addition, work L(0) groups are closed under free product.

On Paranormed Type Fuzzy Real Valued Class of Sequences 2F(p)

  • Sen, Mausumi;Roy, Santanu
    • Kyungpook Mathematical Journal
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    • v.51 no.3
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    • pp.345-352
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    • 2011
  • In this article we introduce the fuzzy real valued double sequence spaces $_2{\ell}^F$ (p) where p = ($p_{nk}$) is a double sequence of bounded strictly positive numbers. We study their different properties like completeness, solidness, symmetricity, convergence free etc. We prove some inclusion results also.

MODULI SPACES OF ORIENTED TYPE ${\mathcal{A}}$ MANIFOLDS OF DIMENSION AT LEAST 3

  • Gilkey, Peter;Park, JeongHyeong
    • Journal of the Korean Mathematical Society
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    • v.54 no.6
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    • pp.1759-1786
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    • 2017
  • We examine the moduli space of oriented locally homogeneous manifolds of Type ${\mathcal{A}}$ which have non-degenerate symmetric Ricci tensor both in the setting of manifolds with torsion and also in the torsion free setting where the dimension is at least 3. These exhibit phenomena that is very different than in the case of surfaces. In dimension 3, we determine all the possible symmetry groups in the torsion free setting.

A DISCRETE FINITE ELEMENT GALERKIN METHOD FOR A UNIDIMENSIONAL SINGLE-PHASE STEFAN PROBLEM

  • Lee, Hyun-Young
    • Journal of applied mathematics & informatics
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    • v.16 no.1_2
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    • pp.165-181
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    • 2004
  • Based on Landau-type transformation, a Stefan problem with non-linear free boundary condition is transformed into a system consisting of parabolic equation and the ordinary differential equations. Semidiscrete approximations are constructed. Optimal orders of convergence of semidiscrete approximation in $L_2$, $H^1$ and $H^2$ normed spaces are derived.