• 천문학회지
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• 제50권1호
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• pp.1-5
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• 2017

Like Hipparcos, Gaia is designed to give absolute parallaxes, independent of any astrophysical reference system. And indeed, Gaia's internal zero-point error for parallaxes is likely to be smaller than any individual parallax error. Nevertheless, due in part to mechanical issues of unknown origin, there are many astrophysical questions for which the parallax zero-point error ${\sigma}({\pi}_0)$ will be the fundamentally limiting constraint. These include the distance to the Large Magellanic Cloud and the Galactic Center. We show that by using the photometric parallax estimates for RR Lyrae stars (RRL) within 8kpc, via the ultra-precise infrared period-luminosity relation, one can independently determine a hyper-precise value for ${\pi}_0$. Despite their paucity relative to bright quasars, we show that RRL are competitive due to their order-of-magnitude improved parallax precision for each individual object relative to bright quasars. We show that this method is mathematically robust and well-approximated by analytic formulae over a wide range of relevant distances.

• 한국소음진동공학회논문집
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• 제17권6호
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• pp.484-490
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• 2007

A reciprocating compressor used in domestic refrigerators can be subjected to many different forms of shock. These shocks are usually experienced during transporting the products from a manufacturer to customers. The hermetic structure of this kind of compressor makes it difficult to conduct drop tests for identifying the failure mechanism and their drop behaviors. The drop/impact simulation for a reciprocating compressor has been carried out with the explicit code LS-DYNA and its validation has been experimentally verified. Simulation results are in good agreement with those of drop test. The present method of drop/impact simulation provides an efficient and powerful solution to improve the design quality and reduce the design period.

• 한국멀티미디어학회논문지
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• 제16권1호
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• pp.19-28
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• 2013

In this research, we presented an effective clustering method based on ICA for the analysis of huge Raman hyperspectral dental data. The hyperspectral dataset captured by HR800 micro Raman spectrometer at UMKC-CRISP(University of Missouri-Kansas City Center for Research on Interfacial Structure and Properties), has 569 local points. Each point has 1,005 hyperspectal dentin data. We compared the clustering effectiveness and the clustering time for the case of using all dataset directly and the cases of using the scores after PCA and ICA. As the result of experiment, the cases of using the scores after PCA and ICA showed, not only more detailed internal dentin information in the aspect of medical analysis, but also about 7~19 times much shorter processing times for clustering. ICA based approach also presented better performance than that of PCA, in terms of the detailed internal information of dentin and the clustering time. Therefore, we could confirm the effectiveness of ICA for the analysis of Raman hyperspectral dental data.

• 한국도시철도학회논문집
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• 제6권4호
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• pp.309-317
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• 2018

Sudden pressure changes caused by the high-speed train entering the entrance of the tunnel are propagated into the tunnel and spread out around the tunnel in the form of a micro pressure wave at the exit of the tunnel. This phenomenon can cause noise and vibration around the tunnel, causing damage to the surroundings. Analysis of this phenomenon is very difficult, but the development of analytical technology has revealed more phenomena than in the past. In this study, we propose this method of analysis and compare it with the experimental data to show the data with higher reliability.

• 한국군사과학기술학회지
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• 제22권4호
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• pp.484-491
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• 2019

General Hyperspectral Image Sensor acquires an image of line form such as a thin rectangle shape because of using 1D array Push Broom or Whisk Broom scanning method. A special mechanism is required for a Hyperspectral Image Sensor to operate for nadir and slant range. To design the mechanism, the characteristics of the flight motion and the overlap rate between consecutive frames were analyzed. Also, system requirements were proposed through modeling and simulation.

• 한국수자원학회논문집
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• 제48권1호
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• pp.37-44
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• 2015

본 연구에서는 Grid method를 사용하여 베이지안 비정상성 확률강우량 산정 모형을 확립하였다. 강우 극치자료의 분포로 Gumbel 분포를 채택하였으며, 분포형의 매개변수에 사전분포를 적용하고, 사전분포에 포함된 매개변수에는 초사전 분포를 적용하여 계층적 베이지안 모형을 구성하였다. Grid method는 매개변수의 발생가능 전 구간에 대하여 확률적으로 더 높은 뒷받침이 있는 하위 구간에서 난수를 직접 생성하여 집합을 구성함으로써 잘못된 결과를 도출할 수 가능성이 높은 상황에서도 보다 정확한 매개변수의 추정을 가능케 하므로 매개변수의 추정과정에서 비표준분포로 나타나는 조건부 확률밀도함수를 통한 난수의 추출은 기존에 사용해 온 Metropolis Hastings 알고리즘이 아닌 Grid method를 사용하였다. 개발된 모형은 서울의 1973년부터 2012년까지의 시강우자료를 이용하여 미래에 대한 재현기간에 따른 확률강수량을 산정하였으며, 그 결과로 기존 정상성 가정에 비해 목표연도에 따라 5%에서 8%정도의 증가율을 나타냈다.

• 한국조경학회지
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• 제47권2호
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• pp.59-75
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• 2019

본 연구는 조경산업의 관점에서 4차 산업혁명 기술을 탐색하여, 선순환적 가치증대에 필요한 기초자료를 제공하고자 수행하였다. 4차 산업혁명, 조경산업과 도시재생의 특성 등을 고찰하고, 체계적 연구에 적합한 기술 분류 체계를 틀로 선정하는 등 방법론을 설정하여 연구하였다. 먼저, 조경산업의 선순환적 가치증대에 활용이 가능한 디지털 데이터 기반의 4차 산업혁명 기술을 선별하였다. '요소기술 수준'에서 '핵심기술'인 사물인터넷, 클라우드 컴퓨팅, 빅데이터, 인공지능, 로봇, '주변기술'인 가상 증강현실, 드론, 3D 4D 프린팅, 3D 스캐닝이 디지털 데이터 기반의 4차 산업혁명 기술로 조명되었다. 조경산업에 특화하여 '트렌드 수준'으로 응용하면 선순환적 가치증대에 활용이 가능한 것으로 나타났다. '시스템 수준'은 하나의 범용기술로 분석하였으며, 플랫폼을 중심으로 요소기술 수준, 컴퓨터와 스마트기기 등이 유기적으로 상호연계되어 시스템화된 디지털 데이터 기반의 4차 산업혁명 기술로 조명되었다. 조경산업에 특화하여 '트렌드 수준'으로 응용하면 선순환적 가치증대에 효과적인 기술로 나타났다. 요소기술 수준을 응용한 트렌드 수준에서 제시된 모든 활용 방안의 구현과 시너지효과 창출이 가능하다. 스마트정원, 스마트공원 등이 추구해야 하는 수준으로 분석되었다. 트렌드 수준의 인접산업 기술 중에는 스마트시티, 스마트홈, 스마트팜 및 정밀농업, 스마트관광, 스마트헬스케어가 협업에 의한 연계성이 클 것으로 판단되었다. 다음으로, 도시재생 공공공간을 포함한 조경공간의 조성 유지관리 및 서비스에서 도구이자 소재로서, 트렌드 수준으로 응용된 관련 기술의 다양한 활용 방안이 조명되었다. 즉, 유비쿼터스 컴퓨팅의 실현으로 조경공간에서 디지털 기술의 기본적 특성이 반영된 초연결화, 초실감화, 초지능화, 초융합화되는 방안들이 제시되었다. 조경산업이 도시재생 사업에 참여함에 있어서도, 기존 업무를 비롯하여 새로운 성격의 요구 수용 및 조율, 교육, 컨설팅 등에서 가치를 증대하는데 효과적인 것으로 분석되었다. 특히, 조경영역 전반이 전략적 교두보로 유지관리를 연계하여, 트렌드 수준의 관련 기술을 시스템화할 때 선순환적 가치증대에 효과적인 것으로 나타났다. 산업구조 상, 다양한 경로에서 생산된 데이터와 정보를 유통시키는데 효과적이기 때문이다. 향후 디지털 데이터 기반의 4차 산업혁명 기술을 실제 조경공간의 조성 유지관리 및 서비스에 융합하여 실증하는 등의 후속적 연구가 필요하다.

• 한국건축시공학회지
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• 제8권2호
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• pp.81-87
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• 2008

High-rise building is taking a place as one of building types from apartment housings to commercial buildings. With taking in account of stability and durability, strength of used materials is increasing gradually in these high-rise buildings. According to this, frequency in use of SD500 re-bar is increasing gradually in high-rise buildings. However the study of SD500 re-bar is insufficient because SD500 re-bar started to be used for domestic buildings lately. Specially because there is no guide or study to refer to, people get into difficulties when to decide the method of re-bar connection in construction using SD500 re-bar. Accordingly in this study, it suggests the method of estimating the economical efficiency on SD500 re-bar connection, and conducts benefit/ cost analysis on lapped splice and coupler splice by applying AHP theory, and then presents its result. After to analyze re-bar diameter of D25, 29, and 32, finally we attained the result that the coupler splice is advantageous in all parts of benefit/ cost more than the lapped splice.

• Journal of Photoscience
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• 제10권2호
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• pp.203-208
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• 2003

Two coupled molecules were successfully synthesized by condensation of amine-donor-substituted barbituric acid derivativies as nonlinear optical chromophores. A flexible spacer of the alkyl chain with different lengths of carbon chains (5 and 6 carbons) was introduced between two chromophores, which prevented crystallization and aggregation of molecules. Two coupled molecules (B-Cn-B, n=5, 6) had glass-transition temperatures on a second heating around 81 and 76$^{\circ}C$ without melting points, respectively. To explore the linear optical properties, thin-films were prepared and examined by a photometry method using Nd:YVO$_4$ CW laser. Also, microscopic and macroscopic nonlinear optical properties were measured by Hyper-Rayleigh Scattering (HRS) and the Maker Fringes method using Nd:YAG ps pulse laser, respectively. In spite of the moderate hyperpolarizabilities of coupled molecules, the second order NLO coefficient (d$\_$33/) was larger than the conventional Disperse Red 1 doped PMMA polymeric system.

• 한국실내디자인학회논문집
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• 제26권2호
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• pp.55-63
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• 2017

Recent projects of Japanese architect, Ito Toyo have been evolved into innovative and experimental stages that are unique and different from other contemporary architects. Since Ito established his own office in 1971, there were several critical changes and developments in terms of architectural philosophy as well as design methods. Particularly, after Sendai Mediatheque, Ito has tended to focus on creating three-dimensional organic body in which architectural form, space, structure, facilities, images are merged all together. With this new type of three-dimensional structure, Ito aims to generate a new notion of architecture as 'living organism'. This paper tried to analyze Ito's new concept of architecture, design process of three-dimensional organic body and its ultimate characteristics and meanings. For the analysis, three projects were selected: Taichung Metropolitan Opera House(2005), Berkeley Art Museum and Pacific Film Archive(2007), The New Deichman Library in Oslo(2008). These projects clearly represent several types of three-dimensional organic body. After the comparative studies, it is found that, in Ito's design process and method, there are unique characters: ambivalent relationship between plan and three-dimensional form, aiming new/hyper reality through complicated collaboration of analogue and digital design tools, and contradictory relationship with surrounding urban context. Although there are some limitations and restrictions, ever-evolving Ito's design concept and methods are very much valid and meaningful in contemporary spatial design in various perspectives.