• 제목/요약/키워드: Mixed Functions

검색결과 446건 처리시간 0.023초

이차 미분을 이용한 경험적 모드분해법 (Empirical Mode Decomposition using the Second Derivative)

  • 박민수;김동호;오희석
    • 응용통계연구
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    • 제26권2호
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    • pp.335-347
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    • 2013
  • 다양한 분야에서 시그널(signal) 형태로 자료들이 표현된다. 예를 들면 심전도(electrocardiogram)는 심근에서 발생하는 활동 전류를 나타내는데, 심장의 박동에 따라 수축과 이완을 반복하는 과정을 시간에 따른 활동 전류량의 변동으로 나타낸다. 현실세계에서 측정하거나 관찰되는 시그널에는 다양한 형태의 시그널들이 혼합되어 있는 경우가 흔하다. 예를 들어 오케스트라 연주의 아름다운 선율은 고유한 주파수(frequency)를 지닌 악기들의 다양한 소리로 구성되어 있으며, 각기 다른 음조(note)가 하나로 모여 완벽한 하모니를 형성하게 된다. 시그널이 정상인(stationary) 경우에 혼합된 시그널들을 분해하여 분석하는 방법에 대해 현재까지 다양하게 연구되어 왔다. 자료가 비정상(non-stationary)일 경우에는 기존의 방법론들을 적용시키기에는 한계가 있다. 비정상성 자료를 다루기 위해 Huang 등 (1998)은 경험적 모드분해법(empirical mode decomposition)이라는 방법을 제안하였다. 자료에 내포되어 있는 국소적인 파동(oscillation)을 국소 극값들(local extrema)을 식별하여 자료 적응적으로 추출한다. 경험적 모드분해법은 잡음(error)에 의해 자료가 오염되어 있는 경우에는 국소 극값들을 통하여 국소적인 파동을 추정하기 어려우며, 자료의 크기가 커짐에 따라 계산량도 크게 늘어나는 단점 등이 있다. 본 연구에서는 이차 미분을 이용하여 국소적인 파동을 식별하고 추정하는 새로운 방법론을 제시하고자 한다.

서해안 방풍림의 식생구조 및 관리 방안 (Vegetation Structure and Management Plan for Windbreak Forests along the West Coast in Korea)

  • 김현준;정성훈;황창혁;김현;최수민;이상현
    • 농업생명과학연구
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    • 제46권1호
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    • pp.71-81
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    • 2012
  • 본 연구는 서해안 주요 8개 방풍림의 식생구조를 분석하고 관리 방안을 모색하여 새만금 유역의 방풍림 구성에 필요한 기초자료를 제공하기 위하여 실시하였다. 8개 방풍림에 출현하는 식물은 총 25과 40속 43종으로 조사되었으며 교목층은 모두 곰솔만으로 구성된 것으로 나타났다. 단일수종의 단층구조를 보이는 방풍림은 2개소이며, 단일수종의 다층구조로 구성된 방풍림은 2개소였으며, 4개 방풍림은 여러 수종의 다층구조로 구성되어 있는 것으로 나타났다. 생태적, 기능적으로 안정적인 방풍림의 구조는 수직적으로 교목층, 아교목층, 관목층이 모두 존재하는 복층구조가 적합하며, 수평적으로는 교목은 내륙쪽에 관목은 해안쪽에 식재를 하는 것이 효과적일 것이다. 또한, 단순림보다는 침엽수와 상록활엽수를 함께 혼합하여 식재하는 혼효림이 방풍림 기능의 효과를 더 향상시킬 것이며 병해충에 대한 피해도 줄어들 것으로 판단된다.

서울 상업용도지역 내 주거 기능 회복의 필요성과 방향 -서울 역사도심과 뉴욕 맨해튼을 중심으로- (The Necessity and Direction for Restoration of Housing Function in Seoul's Central Commercial District -Comparison of Seoul's Historic Center and New York City's Manhattan-)

  • 이연경;이경민;최원우;신중호;김도년
    • 문화기술의 융합
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    • 제8권6호
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    • pp.693-702
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    • 2022
  • 본 연구는 서울보다 일찍이 성장하여 도심 문제해결과 도시 생태계 회복을 위해 주거 공간의 제공에 노력을 기울여온 뉴욕 맨해튼 도심과의 현황의 비교를 통해 서울 역사도심의 도시생태계 불균형의 문제점과 그에 따른 주거 기능 회복의 필요성을 제시하는 데에 목적을 가지고 있다. 주거 공간의 총량, 주거용도 건축물 유형별 특성, 주거용도 건축물의 분포 분석을 통해 도심 상업용도지역 내 주거현황을 조사하였다. 이를 통해, 서울 역사도심은 대부분의 공간이 상업용도에 편향되어 있으며, 도심주거에 적합한 중고밀도의 복합용도 건축물이 맨해튼 도심에 비해 현저히 부족함을 알 수 있었다. 또한 서울 역사도심은 복합용도 건축물이 대상지의 외곽에 인접하여 위치함을 알 수 있었다. 결론적으로 서울 역사도심은 도시 생태계 조성을 위한 적절한 주거 공간을 제공하지 못하고 있으며, 주거 기능 회복을 위한 방안 마련이 필요하다.

VLBI상관서브시스템의 검증을 위한 소프트웨어 시뮬레이터의 개발 및 성능시험 (DEVELOPMENT AND PERFORMANCE EVALUATION OF SOFTWARE SIMULATOR FOR APPROVING OF VLBI CORRELATION SUBSYSTEM)

  • 오세진;노덕규;염재환;정현수;이창훈;김효령;김광동;강용우;박선엽
    • 천문학논총
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    • 제23권2호
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    • pp.73-90
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    • 2008
  • A software simulator is developed for verifying the VLBI Correlation Subsystem (VCS) trial product hardware. This software simulator includes the delay tracking, fringe rotation, bit-jump, FFT analysis, re-quantization, and auto/cross-correlation functions so as to confirm the function of the VCS trial product hardware. To verify the effectiveness of the developed software simulator, we carried out experiments using the simulation data which is a mixed signal with white noise and tone signal generated by software. We confirmed that the performance of this software simulator is similar as that of the hardware system. In case of spectral analysis and re-quantization experiment, a serious problem of the VCS hardware, which is not enough for expressing the data stream of FFT results specified in VCS hardware specification, was found by this software simulator. Through the experiments, the performance of software simulator was verified to be efficient. In future, we will improve and modify the function of software simulator to be used as a software correlator of Korea-Japan Joint VLBI Correlator (KJJVC).

쥐에서 말초 자극에 따른 뇌피질 활성화의 자기공명 영상 (MR imaging of cortical activation by painful peripheral stimulation in rats)

  • 이배환;차명훈;정재준;이규홍;이철현;손진훈
    • 한국감성과학회:학술대회논문집
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    • 한국감성과학회 2009년도 추계학술대회
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    • pp.183-185
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    • 2009
  • As imaging technology develops, magnetic resonance imaging (MRI) techniques have contributed to the understanding of brain function by providing anatomical structure of the brain and functional imaging related to information processing. Manganese-enhanced MRI (MEMRI) techniques can provide useful information about functions of the nervous system. However, systematic studies regarding information processing of pain have not been conducted. The purpose of this study was to detect brain activation during painful electrical stimulation using MEMRI with high spatial resolution. Male Sprague-Dawley rats (250-300 g) were divided into 3 groups: normal control, sham stimulation, and electric stimulation. Rats were anesthetized with 2.5% isoflurane for surgery. Polyethylene catheter (PE-10) was placed in the external carotid artery to administrate mannitol and MnCl2. The blood brain barrier (BBB) was broken by 20% D-mannitol under anesthesia mixed with urethane and a-chloralose. The hind limb was electrically stimulated with a 2Hz (10V) frequency while MnCl2 was infused. Brain activation induced by electrical stimulation was detected using a 4.7 T MRI. Remarkable signal enhancement was observed in the primary sensory that corresponds to sensory tactile stimulation at the hind limb region. These results suggest that signal enhancement is related to functional activation following electrical stimulation of the peripheral receptive field.

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유아 언어능력 평가연구의 동향 분석 -한국학술진흥재단 등재 학회지를 중심으로 (Trend Analysis of Research Using Evaluation Tools of Languages Abilities for Young Children: Based on Early Children Education Journals registered with the Korea Research Foundation)

  • 윤진주
    • 한국생활과학회지
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    • 제16권4호
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    • pp.677-690
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    • 2007
  • This study has a goal to read a trend of language research by analysing evaluation tools and methods that researchers have used for assessing young children's language abilities. Thus the study has chosen 237 language ability evaluation methods out of 121 young child's language ability evaluation researches. The treatises were selected from 4 types of early childhood education journals registered on the Korea Research Foundation. The data analysis was employed for processing the frequency and percentage of the collected data. The results were as follows: First, of single age groups the subject group most selected was five-year-olders and of mixed-age groups the subject group most selected was from three to five, and the number of subjects in researches were mostly below fifty children. The researches were sorted into an 'experimental/ investigational researching' type that has been frequently re-utilized by others, an 'interview type' using a data collection method, and a 'difference verification' type using a data analysis method which has been used in majority of studies. Second, the number of treaties that required data analysis has increased since 1996. Concludingly, the analysis of young child's language ability evaluation tools shows that the purposes of many researches were concentrated on studying children's knowledge about language, children's language functions such as speaking, reading, writing and listening, while evaluation contents were focused on speaking and writing.

시베리아·중앙아시아와 한국 중부지방 무속복식의 비교연구 (A Study of Comparing Shamans' Costumes of the Central Region of Korea with those of Siberia and Central Asia)

  • 이자연
    • 한국의류산업학회지
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    • 제7권4호
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    • pp.387-393
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    • 2005
  • This study compares shamans' costumes of Korea with those of Siberia and Central Asia. It also investigates the meaning of shamanism and shamans,the relationship of Korean shamanism to shamanism, and the genealogy of Korean shamanism. For collecting and analyzing data of the research, literature reviews, field studies, and the investigation of historical relics are mostly used. The following are the major findings of the research: Through the comparison of shamans' costumes of Korea with those of Siberia and Central Asia, this research finds out some similarities and differences in the costumes. Both Korean shamans and Siberian and Central Asian shamans wore shaman's costumes and used utensils like bells or mirrors when they perform a religious service. On their costumes, they both used an element which stands for birds. However, they were different in terms of the materials or styles of the costumes, of the function of the costumes, and of the decorating with ornaments. The differences in the materials or styles of the costumes, different functions of the costumes, and using ornaments or not can be viewed as a general phenomenon, which is resulted from different environments. The soul's departing the body or the possession or a mixed method can be considered as mere variations due to regional or cultural differences. In conclusion, based on the comparison of the costumes of shamans of Korea with those of Siberia and Central Asia, the shamans of Korea and Siberia and Central Asia share the same origin. And the genealogy of Korean shamans can be said to be originated from the northern shamanism.

3절점 및 4절점 요소를 이용한 비등방성 절판 구조물의 해석 (Analysis of Anisotropic Folded Structures using Triangular and Quadrilateral Elements)

  • 유용민;임성순;장석윤
    • 한국전산구조공학회논문집
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    • 제20권1호
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    • pp.29-37
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    • 2007
  • 본 연구에서는 3절점 요소와 4절점 요소를 가지는 비등방성 절판 구조물의 처짐 해석을 수행한다. 절판 구조물을 해석할 때 4절점 요소뿐만 아니라 3절점 요소의 사용이 필요한 경우가 발생하게 된다 그러나 3절점 요소를 사용하는 것은 간단하지 않다. 그러므로 본 연구에서 사용한 3절점 요소는 4절점 요소에서 절점을 감소시키는 방법을 사용하여 계산 과정의 편의성과 3절점 요소의 사용으로 인한 복잡성을 피할 수 있다. 이러한 방법을 고차 전단변형이론에 적용하기 위하여 Lagrangian 보간함수만을 사용한다. 또한 해석과정의 편의성 및 정확성을 위하여 면내회전각 자유도를 도입한다. 특히 본 논문에서는 3절점 및 4절점 요소의 사용에 의한 비등방성 복합적층 절판 구조물의 거동 특성을 분석하며 이에 대한 영향을 다양한 매개변수를 통하여 상세히 규명하고자 한다.

신도시 공동주택 부대복리시설의 배치특성에 관한 연구 - 제 2기 신도시 아파트를 중심으로 - (A Study on Layout Characteristics of Subsidiary Welfare Facilities at Apartment Complexes in New Towns - Focused on Apartment Complexes in Second Phase New Towns -)

  • 문자영;정유리;황연숙
    • 한국실내디자인학회논문집
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    • 제26권3호
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    • pp.81-90
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    • 2017
  • Subsidiary welfare facilities in an apartment complex are one of the most important factors for consumers when they buy an apartment due to an increase of consumers' consciousness level, increase of leisure time, and increase of cultural life. This study aims to analyze layout types and characteristics of subsidiary welfare facilities at the apartment complexes in the second phase new towns, investigate the current situation and find out the improvement direction. For this purpose, this author investigated three "second phase new towns" which were designated as a new town at similar time, and selected a total of 15 apartment complexes by selecting 5 complexes in each of the three new towns. Literature survey, case visit, photo shoot, user observation survey were used as study methods. The results of the study are as follows. First, it was found that a mixed type was the most common type of plane layout types in the subsidiary welfare facilities. This type improves accessibility and equity of the residents as the facilities are appropriately placed based on the functions and the user characteristics. Second, it can be considered that a distributed type for senior citizen centers and daycare centers may give independence to specific users, but it may give a sense of alienation to the elderly. Moreover, it does not have enough community so that it is necessary to make proper supplementation. Third, there were two lay out types. The first one is that the subsidiary welfare facilities are placed with step difference and the second one is that they are placed in sunken places using the underground space. Fourth, all layout types of outdoor facilities are distributed types, and it is considered that measurements for a proper balance of accessibility and equity are required.

"임원십육지(林園十六誌)”의 초류(麨類) 조리 가공에 관한 문헌 연구 (A Study on the Literature of the Cooking Product of Cho(Misutkaru) in Imwonshibyukji)

  • 김귀영;이춘자
    • 동아시아식생활학회지
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    • 제16권4호
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    • pp.377-386
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    • 2006
  • Imwonshibyukji(1827) is an important and stupendous ancient scientific book, which is much like an encyclopedia, that can discern the dietary life of the latter period of Choseon. This article is assorted, which is mentioned in this book, as Cho(Misutkaru-in parched grain that is weed out into powder) to the main material of grain Youmicho, Wandoocho, Youcho, also the medicinal plant as the main material Youkhangcho, Backyupcho, Chungumcho, Unyoungcho, and Naecho, Haengcho, Eicho, Imgumcho, Joyou, Bokbunjacho, made by fruit. The results of inquiring the property by the assortment is as you see in the following. Youmicho, Wandoocho, Youcho, Youkhyangcho, Backyupcho, and Chungumcho, which consist of glutinous rice, nonclutinous rice, barley, buckwheat, pea, and black soybean are among 13 kinds of methods to make Cho. The manufacturing process is similar to that of Misutkaru, but in the case of Unyoungcho 6 different medicinal powders are mixed with Chundang and Sookmill to form a hard portable taffy substance, which is quite unique. Naecho, Haengcho, Eicho, Imgumcho, Joyou, and Bokbunjacho are extracted from pulp and processed in a powder form like Misutkaru, which can also be considered as a fruit tea. Youcho is unique in its sense, since it is fermented by maggots that are bred in order to obtain the juice. Cho is known to calm thirst and empty stomachs, and has various medicinal materials to act as food to aid virility. It is also known to have multiple functions as an alternative staple, refreshment to aid virility, portable food, and preferable beverage. There are ten references on Cho, 37% are Korean in Ongheejobji and 63% Chinese in Jaeminyosool, Bonchogangmok, Chungmoonbobang, Nongjungchunsuh, Wangshinongsuh, Shikgyung, Sukmyung, Bonchoseupyou, and Wisaengbogam. The citations are in the general introduction and 13 types of Cho are cited 19 times overall, but citations based on Chinese references are non existe.

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