• Journal of the Optical Society of Korea
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• 제15권3호
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• pp.216-221
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• 2011

A diffraction grating is a highly symmetric optical element with a physical structure that is invariant under translational spatial movements. The translational symmetry is reflected in the fields that are diffracted from the grating. Here, we introduce a plane-parallel mirror pair onto the grating, which translates the fields through double reflections, and we describe a method of exploiting the symmetry to enhance the spectral resolution of a diffraction grating beyond the limit that is set by the number of grooves. The mirror pair creates another virtual grating beside the original one, effectively doubling the number of grooves. Addition of more mirror pairs can further increase the effective number of grooves despite the increased complexity and difficulty of experimental implementation. We experimentally demonstrate the spectral linewidth reduction by a factor of four in a neon fluorescence spectrum. Even though the geometrical restriction on the mirror deployment limits our method to a certain range of the whole spectrum, as a practical application example, a bulky spectrometer that is nearly empty inside can be made compact without sacrificing the resolution.

• 한국조경학회지
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• 제32권5호
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• pp.129-138
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• 2004

Cherishing the dead is based in sadness. Designing a memorial space therefore has an inherent challenge to evoke the feeling that is so personal and varied by providing a physical space. The tendency of memorials, especially in the US after the mid 20th century, has been to emphasis each dead individual, as seen at the Vietnam Veterans Memorial in Washington, D. C., the Oklahoma City National Memorial in Oklahoma City, and so forth. In the process of designing the memorial of the Taiwanese Chi-chi earth-quake, Cheng Kim Park Robidoux tried to set up a series of spaces through which not only the relatives of the dead but also unrelated visitors could have their own spatial experiences, private rituals and public events, so that they can finally build up a collective memory. Sky-Well consists of a large bamboo forest enclosing a void. Without a particular entrance and guiding system, visitors stroll and get lost in the bamboo forest before they find the central void. The horror they experienced during the earthquake is melted down into the motion and phenomenology of the bamboo forest whereas the central void is reinterpreted as an empty mind, where people find solace from the sky. Details, such as the bamboo wall to place commemorative flowers and lotus blossom paving, are echoing the theme of rebirth.

• Bulletin of the Korean Chemical Society
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• 제25권1호
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• pp.85-89
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• 2004

Geometrical structures of [Pd(L)$Cl_2$] with oxathia macrocycles have been calculated using ab initio secondorder Moller-Plesset (MP2) and Density Functional Theory (DFT) methods with triple zeta plus polarization (TZP) basis set level. In optimized Pd(L)$Cl_2$ complexes, Pd(II) locates at the center surrounded by a square planar array of two sulfurs on an oxathia macrocycle and two chlorides. The endo-Pd(II) complexes with an axial (Pd${\cdots}$O) interaction are more stable than the exo-Pd(II) complexes without the interaction. In the endo-Pd(II) complexes, the atomic charge of the oxygen atom moves to Pd(II) via the axial ($Pd{\cdots}$O) interaction and then, the charge transfer from Pd(II) to the S-atoms occurs stepwise via ${\pi}$-acceptors of the empty d-orbitals.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권1호
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• pp.350-364
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• 2022

Traditionally, in multi-user multi-carrier systems, the neighboring subband will be gapped by one subcarrier, which is set as guard band to reduce multiple access interference (MAI) between neighboring subbands. The empty subcarrier for guard band will degrade the spectral efficiency of the whole system. In order to enhance the spectral efficiency of multi-user filter bank multiple carrier (FBMC) systems, a new subband allocation method is introduced, in which the neighboring subband is gapped by half subcarrier instead of one subcarrier. Meanwhile, in order to implement the proposed resource allocation scheme, an optimized FBMC prototype filter is designed to decrease the inter-subband interference to the neighboring subband. The detailed simulations about the comparison between the proposed spectrum assignment and traditional FBMC are given, as well as the performance in the different interference scenarios. The simulation results show that the combination of the proposed spectrum assignment scheme and the optimized filter has better performance compared to the traditional scheme. The proposed scheme can be used in the system which serves massive users to get higher spectrum efficiency.

• 대한수학회보
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• 제59권3호
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• pp.697-707
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• 2022

It is well known that the continued fraction expansion of ${\sqrt{d}}$ has the form $[{\alpha}_0,\;{\bar{{\alpha}_1,\;{\ldots},\;{\alpha}_{l-1},\;2_{{\alpha}_0}}]$ and ${\alpha}_1,\;{\ldots},\;{\alpha}_{l-1}$ is a palindromic sequence of positive integers. For a given positive integer l and a palindromic sequence of positive integers ${\alpha}_1,\;{\ldots},\;{\alpha}_{l-1},$ we define the set $S(l;{\alpha}_1,\;{\ldots},\;{\alpha}_{l-1})\;:=\;\{d{\in}{\mathbb{Z}}{\mid}d>0,\;{\sqrt{d}}=[{\alpha}_0,\;{\bar{{\alpha}_1,\;{\ldots},\;{\alpha}_{l-1},\;2_{{\alpha}_0}}],\;where\;{\alpha}_0={\lfloor}{\sqrt{d}}{\rfloor}\}.$ In this paper, we completely determine when $S(l;{\alpha}_1,\;{\ldots},\;{\alpha}_{l-1})$ is not empty in the case that l is 4, 5, 6, or 7. We also give similar results for $(1+{\sqrt{d}})/2.$ For the case that l is 4, 5, or 6, we explicitly describe the fundamental units of the real quadratic field ${\mathbb{Q}}({\sqrt{d}}).$ Finally, we apply our results to the Mordell conjecture for the fundamental units of ${\mathbb{Q}}({\sqrt{d}}).$

• 문화기술의 융합
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• 제6권3호
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• pp.67-74
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• 2020

중년여성들은 여성성의 상실과 함께 신체적, 정신적 변화를 겪게 되며, 자녀의 성장과 독립으로 돌봄과 양육의 역할이 감소되면서 심리적으로 공허함을 느끼기도 한다. 이 여성들은 자신의 역할감소에 따른 상실감과 공허함을 자신의 여가생활을 위해 자신의 가치관과 신념을 유지하는 계기로 이해하고 있다. 이에 중년여성들은 공예활동체험을 통하여 인간과 인간의 소통을 통한 사회적 관계에서 이루어지는 관계형성과 자아실현의 기회로 인식하여 우울감이나 공허한 마음과 같은 중년의 위기에 나타나는 부정적 감정을 극복하고 자아존중감과 사회적 지지를 확립하고 있다. 우리는 이 연구에서 공예활동의 체험요소가 중년여성의 자아존중감과 사회적 지지에 미치는 영향을 분석하기 위하여 공예활동의 체험요소를 독립변수로, 자아존중감과 사회적 지지를 종속변수로 하는 연구모형을 설정하였다. 연구결과 교육적 체험, 오락적 체험, 일탈적 체험은 자아존중감에 유의한 영향을 미치고 있으나 심미적 체험은 유의한 영향을 미치지 못하고 있다. 그리고 오락적 체험, 심미적 체험은 사회적 지지에 유의한 영향을 주지만 교육적 체험, 일탈적 체험에는 유의한 영향을 주지 못하였다. 따라서 중년여성의 감각과 감성의 변화에 영향을 줄 수 있는 체험공간의 환경적 특성인 미학적 요소와 시각적 요소를 살릴 수 있는 콘텐츠와 교류할 수 할 수 있는 출발에서 접근할 수 있도록 공예체험에 대하여 제도적으로 지원하는 방안이 제공되어야 한다. 그리고 공예활동으로 궁극적인 삶에 변화를 주는 요인을 고려하지 않은 한계가 있어 웰빙과 관련된 변수 등을 도출하여 새로운 모형을 제시할 것을 제안하고자 한다.

• KIEAE Journal
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• 제10권2호
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• pp.9-18
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• 2010

As an aging population has increased vastly and nuclear families have been a dominating family type in modern Korean society, the numbers of the elderly who suffer Empty Nest Syndrome and LID (Loss Isolation Depression) syndrome have been accelerated. These syndromes involve psychological instability, melancholy, and lethargy. To make the elderly get out of this phenomenon and live actively, the scheme of converting their existing house into shared housing was set as a hypothetical solution in this study. This study sets out to find out responses of the elderly to alter their own house's function in housing improvement area. A Small Workshop Panel method was used and the elderly aged 55 years upwards took part and they own a detached house in a housing improvement area that is relatively large for the elderly or the elderly couple to live alone. Through the workshop, problems that the elderly have been experiencing within their houses were looked into and responses of the elderly on altering their house to shared housing by introducing developed schematic plans. Although, the first response was negative, positive responses from the house owners were carried out when a visual support i.e. developed shared housing plan was provided. The positive response was based on the fact that subsidies from the government on house renovation and tenants matching programs are supported as shared housing could provide home owners economical support with rents and help them to feel less lonely. This is a way of relieving the elderly from being neglected and supporting them to live and age actively in their later lives. Furthermore, by providing a visual media to the elder residents in housing improvement area, their greater understandings on the development and addressing their opinions were possible. Therefore, more tools that promote elder residents' participation are needed for future housing improvement projects and an aging society.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2008년 추계학술발표대회 논문집
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• pp.131-134
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• 2008

The numbers of the elderly who suffer Empty Nest Syndrome have been accelerated as an aging population has increased vastly and nuclear families have been a dominating family type in modern Korean society. To make the elderly get out of this phenomenon and live actively, the scheme of converting their existing houses into shared houses was set as a hypothetical solution in this study, and finding out the responses of the elderly who owns their own houses is the purpose of the study. A small workshop panel method was used and the elderly aged 55 years upwards took part and they own a detached house that is relatively large for the elderly or the elderly couple to live alone. The workshop was consisted of 3 stages: 1. a survey 2. an interview 3. a site visit. Through this, problems that the elderly have been experiencing within their houses were looked into and the responses of the elderly on converting their houses to shared houses by introducing developed schematic plans. As a result, positive responses from the house owners were carried out based on the fact that subsidies from the government on house renovation and tenants matching programs are supported. Shared houses could provide home owners economical support with rents and help them to feel less lonely. This is one way of supporting the elderly to live and age actively in their later lives. Therefore, this idea should be established in connection with preparing aging, aged, and super-aged society.

• Advances in Computational Design
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• 제5권4호
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• pp.363-380
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• 2020

In this paper, a cylindrical shell is immersed in a non-viscous fluid using first order shell theory of Sander. These equations are partial differential equations which are solved by approximate technique. Robust and efficient techniques are favored to get precise results. Employment of the Rayleigh-Ritz procedure gives birth to the shell frequency equation. Use of acoustic wave equation is done to incorporate the sound pressure produced in a fluid. Hankel's functions of second kind designate the fluid influence. Mathematically the integral form of the Lagrange energy functional is converted into a set of three partial differential equations. Throughout the computation, simply supported edge condition is used. Expressions for modal displacement functions, the three unknown functions are supposed in such way that the axial, circumferential and time variables are separated by the product method. Comparison is made for empty and fluid-filled cylindrical shell with circumferential wave number, length- and height-radius ratios, it is found that the fluid-filled frequencies are lower than that of without fluid. To generate the fundamental natural frequencies and for better accuracy and effectiveness, the computer software MATLAB is used.

• 한국컴퓨터그래픽스학회논문지
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• 제14권2호
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• pp.27-33
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• 2008

본 논문에서는 입력으로 들어온 사람의 얼굴 영상으로부터 간략하면서도 인물의 특성이 잘 반영되도록 스타일화된 일러스트레이션 영상을 만드는 방법을 제시한다. 이를 위해 입력으로 들어온 영상으로부터 얼굴 영역 및 각 구성요소들을 인식하고, 그 결과를 효과적인 스타일화에 이용한다. 실제 스타일화는 크게 주요 부분을 간단한 톤으로 표현해주는 톤 그리기 부분과 해당 부분을 적은 선으로 효과적으로 묘사하는 선 그리기 부분으로 나뉘며, 이 두 부분에 머리카락이 나 옷 부분 등에 추가적인 효과를 더하여 이루어진다. 이러한 스타일화 과정은 일반적으로 사람이 그린 그림과 같이 극도의 추상화과정을 거쳐 보다 적은 표현으로 대상의 특징을 잘 살려주는 것을 목적으로 한다. 이를 위해 여백을 살리는 간단한 표현으로도 대상을 효과적으로 묘사하는 동양화 기법을 응용한다.