• Advances in aircraft and spacecraft science
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• 제3권3호
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• pp.351-366
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• 2016

Macroperforations improve the sound absorption performance of porous materials in acoustic cavities and in waveguides. In an acoustic cavity, enhanced noise reduction is achieved using porous materials having macroperforations. Double porosity materials are obtained by filling these macroperforations with different poroelastic materials having distinct physical properties. The locations of macroperforations in porous layers can be chosen based on cavity mode shapes. In this paper, the effect of variation of macroporosity and double porosity in porous materials on noise reduction in an acoustic cavity is presented. This analysis is done keeping each perforation size constant. Macroporosity of a porous material is the fraction of area covered by macro holes over the entire porous layer. The number of macroperforations decides macroporosity value. The system under investigation is an acoustic cavity having a layer of poroelastic material rigidly attached on one side and excited by an internal point source. The overall sound pressure level (SPL) inside the cavity coupled with porous layer is calculated using mixed displacement-pressure finite element formulation based on Biot-Allard theory. A 32 node, cubic polynomial brick element is used for discretization of both the cavity and the porous layer. The overall SPL in the cavity lined with porous layer is calculated for various macroporosities ranging from 0.05 to 0.4. The results show that variation in macroporosity of the porous layer affects the overall SPL inside the cavity. This variation in macroporosity is based on the cavity mode shapes. The optimum range of macroporosities in poroelastic layer is determined from this analysis. Next, SPL is calculated considering periodic and nodal line based optimum macroporosity. The corresponding results show that locations of macroperforations based on mode shapes of the acoustic cavity yield better noise reduction compared to those based on nodal lines or periodic macroperforations in poroelastic material layer. Finally, the effectiveness of double porosity materials in terms of overall sound pressure level, compared to equivolume double layer poroelastic materials is investigated; for this the double porosity material is obtained by filling the macroperforations based on mode shapes of the acoustic cavity.

• Journal of Information Science Theory and Practice
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• 제9권4호
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• pp.50-62
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• 2021

This study aims to unravel the shift in the customary method of disseminating information about the ritual of Perang Topat (literally translated as "rice-cake war") as carried out by the custom community of Kemaliq Lingsar in the West Lombok Regency of Indonesia during the COVID-19 pandemic. Grounded in the ethnography of communication research methodology, this study examines the process of the cultural ritual during the 2020 period of the pandemic and compares it to the ones held in 2018 and 2019 (before the current pandemic). Drawing on findings from observations, in-depth interviews, and documentation, it was revealed that the traditional or custom-oriented community of Kemaliq Lingsar abandoned all three prominently used methods of disseminating the information of the Perang Topat ritual that had been used prior to the pandemic, and that they were replaced by a strategy with solely face-to-face (FTF) interpersonal communication carried out by visiting the homes of the target participants of the cultural event. This method was relevant to the current viral crisis because it enabled the committee to minimize the number of spectators which might potentially violate COVID-19 health protocols. This finding also reinforces the hypothetical statement that interpersonal communication via FTF is effective in disseminating information in a limited manner and empowering the emotional bond between the individuals who share relationships and similar interests. The findings of the present study can be a reference for any events where physical distancing must be strictly imposed and require a limit to the number of participants during the pandemic.

• 철학연구
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• 제130권
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• pp.161-186
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• 2014

웰빙'(well being)과 함께 최근 '웰다잉'(well dying)에 대한 사회적 관심이 '안락사'(安樂死) 문제를 계기로 촉발되어 인간 죽음의 존엄성에 대한 중요한 담론으로 대두되고 있다. '웰다잉'(well dying)은 그 어의대로 '좋은 죽음'을 의미하며, 이런 의미적 맥락의 연장선상에서 통상적으로 '준비된 죽음', '품위 있는 죽음', '아름다운 죽음'을 지칭한다. 본고에서 논자는 '죽음'을 교학의 출발점으로, 그리고 '죽음의 극복'을 교학의 종착점으로 삼고 있는 불교의 죽음관이 웰다잉에 대한 담론에 어떠한 기여를 할 수 있는지 면밀히 고찰하였다. 불교의 죽음에 대한 태도와 해석, 그리고 그 극복의 과정은 웰다잉에 대한 보다 풍부한 담론을 형성하는 단초가 되며, 특히 죽음의 극복을 육체적 생리적 영생으로서가 아닌 정신적 심리적 현상으로 해석하고 이러한 정신적 심리적 변화를 통한 사물의 진실상(眞實相)에 대한 깨달음[정각(正覺)]을 통해서 죽음을 극복하는 불교의 견해는 죽음불안의 극복 및 죽음교육에 많은 기여를 할 수 있다.

• 한국경제지리학회지
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• 제21권4호
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• pp.409-424
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• 2018

독일 도르트문트시는 전통적 공업도시로 한때 유럽 최대의 공업지역인 루르의 중심도시였다. 그러나 1950년대 이후 탈산업화로 인해 심각한 피해가 있었다. 그 후 도르트문트는 공격적이고 지속적인 지역재생정책과 사업으로 도시의 면모를 바꾸어 나아가고 있다. 1990년대에는 루르지역 전체를 대상으로 한 국제건축공모전으로, 2000년대에는 자체적인 도르트문트 프로젝트로, 그리고 2010년대에는 스마트 시티 전략으로 지역을 혁신하는 가운데 도시의 성장경로를 바꾸어 나아가고 있다. 본 연구는 도르트문트의 이러한 지역재생정책의 성과를 분석하고, 그러한 성과가 나타나게 하는 행위주체의 역할과 그들간의 관계를 규명하고자 한다. 본 연구는 지역혁신체제론과 경로이론에 입각하여 필자가 수집한 다양한 자료를 분석하고, 정책적, 이론적 시사점을 도출하였다.

• 여성건강간호학회지
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• 제25권3호
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• pp.315-328
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• 2019

Purpose: The purpose of this study was to explore the components and nature of happiness in middle-aged women in Korea. Methods: Thirty middle-aged women living in metropolitan Seoul and Gyeonggi and Chungcheong provinces agreed to participate in this study. The data were collected through in-depth interviews with the participants in one-on-one settings. The data were analyzed qualitative using Colaizzi's method of phenomenology. Results: The three theme clusters were extracted from the raw data, along with 13 themes and 138 meaningful sentences and phrases. The three happiness theme clusters in middle-aged women were "live healthy for stability," "rule one's mind for harmony," and "activate hopes for self-esteem." The first theme cluster included healthy life, economic stability, physical youth, and positive thought. The second theme cluster included that harmonious family, ruling of mind, my position as invisible person in social relationships, and precious relationships to support. The last theme included the center of one's life is oneself, a sense of accomplishment, self-improvement, recognition of one's worth and rest for one self. The three theme clusters were associated with the existence, relatedness, and growth (ERG) of ERG areas, respectively. Conclusions: We conclude that the core components of happiness in middle-aged women are to live healthy and mind-ruled and activate hope. The nature of happiness is egocentric stability in middle-aged women. The results suggest that theme clusters might be used to develop a scale for measuring happiness in middle-aged women. This will be helpful to assess the psychosocial status of middle-aged women in Korea.

• Geomechanics and Engineering
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• 제19권3호
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• pp.255-268
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• 2019

Taking top-coal caving mining face (TCCMF) as research object, this paper considers the combination of top-coal and immediate roof as cushion layer to build the solution model of support resistance based on the theory of elastic foundation beam. Meanwhile, the physical and mechanical properties of coal-rock combination influencing on strata behaviors is explored. The results illustrate that the subsidence of main roof in coal wall increases and the first weighting interval decreases with the increase of top-coal and immediate roof thicknesses as well as the decrease of top-coal and immediate roof elastic modulus. Moreover, the overlying strata reflecting on support has negative and positive relationship with top-coal thickness and immediate roof thickness, respectively. However, elastic modulus has limit influence on the dead weight of top-coal and immediate roof. As a result, it has similar roles on the increase of total support resistance and overlying strata reflecting on support in the limit range of roof control distance. In view of sensitive analysis causing the change of total support resistance, it can be regards as the rank of three components as immediate roof weight > overlying strata reflecting on support > top coal weight. Finally, combined with the monitoring data of support resistance in Qingdong 828, the validity of support resistance determined based on elastic foundation beam is demonstrated, and this method can be recommended to adopt for support type selecting in TCCMF.

• 대한방사선기술학회지:방사선기술과학
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• 제42권5호
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• pp.329-334
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• 2019

This study was purpose to quantitative evaluation of noise power spectrum(NPS) and studied the quantitative evaluation and characteristics of modulation transfer function(MTF) by obtain the optimal edge image by using Coil in magnetic resonance imaging(MRI) equipment through Fujita theory using edge method. The MRI equipment was used (Tim AVANTO 1.5T, Siemense healthcare system, Germany) and the head matrix coil were 12channels(elements) receive coil. The NPS results of showed the best value of 0.004 based on the T2 Nyquist frequency of $1.0mm^{-1}$, and the MTF results of showed that the T1 and T2 values were generally better than the T1 CE and T1 CE FC values. The characteristics of this study were to explain the characteristic method of image quality evaluation in general. To present the quantitative evaluation process and results in the evaluation of MRI image characteristics in radiology.

• 한국융합학회논문지
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• 제11권12호
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• pp.137-145
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• 2020

본 연구는 중국의 문화 성향이 국내 중국인 집단거주지역에서 물리적 건조환경의 변화에 대한 영향과 두 요소간 연관성을 분석하고자 한다. 이를 위해서 국가의 문화를 정량적으로 정의하고 비교할 수 있는 호프스테드의 cultural dimension 이론을 활용하여 중국의 문화 성향을 조사하고, 선행연구를 통한 선정한 환경평가요소를 기준으로 대상지를 실증조사하고 문화 성향과의 연관성을 분석하였다. 본 연구를 통해 중국인의 집단주의적이고 불확실성회피하는 성향이 대림2동의 중국인 집단거주지역의 건조 환경 형성과 변화에 영향을 미친 것을 확인하였다. 본 연구는 이주민 공동체의 문화 성향이 집단거주지 형성과 변화에 영향을 미친다는 것을 확인한 것에 의의가 있으며 이를 통해 차이나타운을 포함한 다양한 이주민 공동체마다 적합한 정책을 마련하는데 기초자료로 활용될 수 있을 것이다.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제10권1호
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• pp.19-28
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• 2021

최근 교육 분야에서는 가상현실 기술을 교육현장에 접목하여 교육 매체로 사용을 하고자 하는 시도들이 다양하게 진행되고 있다. 이에 과학교과 방면에서도 가상현실 환경 구축 기술을 이용하여 공간 및 상황 등의 여러 제한에서 벗어나 보다 다양하고 활동적인 실험을 할 수 있는 과학 실험 시뮬레이션을 필요로 하고 있다. 본 연구에서는 과학교과 중 물리 과목을 선택하여 물리 현상 중 하나인 포물선 운동 공식을 활용한 실험 시뮬레이션을 가상현실 공간에 구현한 뒤, 융합인재교육(STEAM) 이론의 학습 준거를 기준으로 실제 물리 교육에 활용이 가능함을 증명하였다. 이를 통해 가상현실 공간을 활용한 구체적인 교육 모형을 설계할 수 있음을 확인하였고, 전통적인 교육 모형과 현대적 기술의 접목으로 여러 교과에서 보다 효과적인 학습 방법으로 교육을 진행할 수 있음을 보여준다. 연구 결과와 관련하여 향후 연구 방안 및 실제 교육현장에서의 활용 가능성을 시사한다.

• Current Applied Physics
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• 제18권12호
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• pp.1465-1472
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• 2018

The magnetic and optical properties of Ce-doped ZnO systems have been widely demonstrated, but the effects of different strains of Ce-doped ZnO systems remain unclear. To solve these problems, this study identified the effects of biaxial strain on the electronic structure, absorption spectrum, and magnetic properties of Ce-doped ZnO systems by using a generalized gradient approximation + U (GGA + U) method with plane wave pseudopotential. Under unstrained conditions, the formation energy decreased, the system became stable, and the doping process became easy with the increase in the distances between two Ce atoms. The band gap of the systems with different strains became narrower than that of undoped ZnO without strain, and the absorption spectra showed a red shift. The band gap narrowed, and the red shift became weak with the increase of compressive strain. By contrast, the band gap widened, and the red shift became significant with the increase of tensile strain. The red shift was significant when the tensile strain was 3%. The systems with -1%, 0%, and 1% strains were ferromagnetic. For the first time, the magnetic moment of the system with -1% strain was found to be the largest, and the system showed the greatest beneficial value for diluted magnetic semiconductors. The systems with -3%, -2%, 2%, and 3% strains were non-magnetic, and they had no value for diluted magnetic semiconductors. The ferromagnetism of the system with -1% strain was mainly caused by the hybrid coupling of Ce-4f, Ce-5d, and O-2p orbits. This finding was consistent with Zener's Ruderman-Kittel-Kasuya-Yosida theory. The results can serve as a reference for the design and preparation of new diluted magnetic semiconductors and optical functional materials.