• 제목/요약/키워드: Top-down Approach

검색결과 213건 처리시간 0.021초

Change in the treatment strategy for pediatric Crohn's disease

  • Kim, Mi-Jin;Choe, Yon-Ho
    • Clinical and Experimental Pediatrics
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    • 제53권9호
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    • pp.830-833
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    • 2010
  • Crohn's disease is characterized by chronic inflammation involving any portion of the gastrointestinal tract. Treating Crohn's disease is a major challenge for clinicians, as no curative therapy currently exists. Pediatric Crohn's disease is characterized by frequent relapses, a wide extent of disease, a high prevalence of extraintestinal manifestations, and a severe clinical course. The classic therapeutic approach is known as the 'step-up' strategy, and follows a progressive course of treatment intensification as disease severity increases. Although this approach is usually effective for symptom control, many patients become either resistant to or dependent on corticosteroids. The efficacy of infliximab suggests that, rather than a progressive course of treatment, early intense induction may reduce complications associated with conventional treatment and improve quality of life. Intensive early therapy with infliximab is known as the 'top-down' strategy. Such therapy offers the potential for altering the natural history of Crohn's disease, and is changing treatment paradigms. However, the relatively new concept of an early aggressive or 'top-down' treatment approach is not yet widely accepted, especially in pediatric patients. The results of our current study demonstrate that early and intensive treatment of pediatric Crohn's disease patients with infliximab, at initial diagnosis, was more effective for maintaining remission and reducing flares.

Analysis of the effect of the top-down teaching method for training of developing contents based on smart media

  • Ku, Jin-Hee
    • International Journal of Contents
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    • 제7권4호
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    • pp.64-69
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    • 2011
  • Recently, as smart devices are distributed more and more, the need for education of developing contents based on smart media increases. In order to develop contents based on smart media, it is necessary to learn new programming language as well as to understand the structure of platforms as device-manufacturers and communication companies have different platforms. Generally, the problem in education of programming is that it can provide learning to understand the language stage by stage, but it is difficult to suggest a clear result such as completion of learner's project from macroscopic and integrated approach. Especially, there is a difficult of learning several programming languages due to the characteristics of platforms in developing smart contents. Accordingly, in the education of programming for developing smart contents, it is not appropriate to use the traditional teaching method of programming which conducts projects from an integrated point of view after learning the grammatical elements of the language. This paper aims to suggest the top-down teaching method as an effective teaching method for developing contents based on smart media, and to analyze the effect after developing and applying the suggested teaching model.

WCDMA용 67-dB DR, 1.2-V, $0.18-{\mu}m$ 시그마-델타 모듈레이터 설계 (A 67dB DR, 1.2-V, $0.18-{\mu}m$ Sigma-Delta Modulator for WCDMA Application)

  • 김현중;유창식
    • 대한전자공학회논문지SD
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    • 제44권6호
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    • pp.50-59
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    • 2007
  • [ $0.18-{\mu}m$ ] CMOS 공정에서 1.2-V 2차 Full-Feedforward 구조의 ${\Sigma}{\Delta}$ 모듈레이터를 설계하였다. Full-Feedforward 구조는 Op-Amp의 성능 요구치를 크게 경감시키기 때문에 저전압 저전력 ${\Sigma}{\Delta}$ 모듈레이터를 만들기에 적합한 구조로 세계적으로 많이 채택되고 있는 추세이다. 그리고, Top-Down 설계 기법을 적용하여 ${\Sigma}{\Delta}$ 모듈레이터를 설계하였는데, 이를 위하여 Op-Amp의 유한한 DC-Gain과 Bandwidth 등 여러 가지 비이상적 효과들을 모델링하여 전달함수를 유도하였다.

Protein Structural Characterization by Hydrogen/Deuterium Exchange Mass Spectrometry with Top-down Electron Capture Dissociation

  • Yu, Hai Dong;Ahn, Seonghee;Kim, Byungjoo
    • Bulletin of the Korean Chemical Society
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    • 제34권5호
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    • pp.1401-1406
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    • 2013
  • This study tested the feasibility of observing H/D exchange of intact protein by top-down electron capture dissociation (ECD) mass spectrometry for the investigation of protein structure. Ubiquitin is selected as a model system. Local structural information was obtained from the deuteration levels of c and $z^{\cdot}$ ions generated from ECD. Our results showed that ${\alpha}$-helix region has the lowest deuteration level and the C-terminal fraction containing a highly mobile tail has the highest deuteration level, which correlates well with previous X-Ray and HDX/NMR analyses. We studied site-specific H/D exchange kinetics by monitoring H/D exchange rate of several structural motives of ubiquitin. Two hydrogen bonded ${\beta}$-strands showed similar HDX rates. However, the outer ${\beta}$-strand always has higher deuteration level than the inner ${\beta}$-strand. The HDX rate of the turn structure (residues 8-11) is lower than that of ${\beta}$-strands (residues 1-7 and residues 12-17) it connects. Although isotopic distribution gets broader after H/D exchange which results in a limited number of backbone cleavage sites detected, our results demonstrate that this method can provide valuable detailed structural information of proteins. This approach should also be suitable for the structural investigation of other unknown proteins, protein conformational changes, as well as protein-protein interactions and dynamics.

상·하향 통합모형을 활용한 농업 수자원 부족의 경제적 효과 분석 (Economic Impacts of Agricultural Water Shortages in Korea - A Combined Top-down and Bottom-up Model Analysis -)

  • 이승호;권오상;강성원
    • 농촌계획
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    • 제23권4호
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    • pp.111-126
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    • 2017
  • This study analyzes the impacts of agricultural water shortages in Korea using a combined top-down and bottom-up model. A multi-region multi-output agricultural sector model with detailed descriptions of production technologies and water and land resource constraints has been combined with a standard CGE model. The impacts of four different water shortage scenarios were simulated. It is shown that an active adaptation of crop choices occurs in even the regions with relatively abundant water resources in order to respond to the change in relative output prices caused by water shortages. We found that although the losses in production values are not quite large despite water shortages due to the price feedbacks, the loss in GDP is substantial. We show that our combined approach has advantages in deriving region and product specific production effects as well as the overall GDP loss effect of water shortages.

Top-Down Crack Modeling of Asphalt Concrete based on a Viscoelastic Fracture Mechanics

  • Kuai, Hai Dong;Lee, Hyn-Jong;Zi, Goang-Seup;Mun, Sung-Ho
    • 한국도로학회:학술대회논문집
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    • 한국도로학회 2008년도 추계학술대회 논문집
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    • pp.93-102
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    • 2008
  • An energy based crack growth model is developed in this study to simulate the propagation of top-down cracking in asphalt pavements. A viscoelastic fracture mechanics approach, generalized J integral, is employed to model the crack growth of asphalt concrete. Laboratory fatigue crack propagation tests for three different asphalt mixtures are performed at various load levels, frequencies and temperatures. Disk-shaped specimens with a proper loading fixture and crack growth monitoring system are selected for the tests. It is observed from the tests that the crack propagation model based on the generalized J integral is independent of load levels and frequencies, while the traditional Paris' law model based on stress intensity factor is dependent of loading frequencies. However, both models are unable to take care of the temperature dependence of the mixtures. The fatigue crack propagation model proposed in this study has a good agreement between experimental and predicted crack growth lives, which implies that the energy based J integral could be a better parameter to describe fatigue crack propagation of viscoelastic materials such as asphalt mixtures.

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감각통합기능장애를 가진 청소년의 작업수행에 초점을 맞춘 작업치료 사례 (Occupation-based Occupational Therapy for an Youth With Sensory Integrative Dysfunction - A Single Case Study)

  • 지석연;이경민;김미선
    • 대한감각통합치료학회지
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    • 제6권1호
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    • pp.47-62
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    • 2008
  • 서론: 감각통합은 작업치료의 치료적 중재 근거이론(frames of reference)들에서 가장 중요하고 널리 사용되는 것 중 하나이다. 이는 작업치료사인 Jean Ayres가 클라이언트의 적응행동을 향상하기 위한 목적을 두고 발전된 이론이며, 시작된 이래로 많은 작업치료사들이 같은 목표를 가지고 적용해 왔기 때문이다. 감각통합이론을 적용하는 작업치료사로써, 임상에서 감각통합과 그 목표가 되는 적응행동인 작업수행을 치료의 결과로써 증명해 내는 것은 작업치료의 목표가 작업수행의 향상을 전제로 하는 것이기에 매우 중요하며 도전이 되는 것이다. 본론: 본 연구는 작업치료중재과정모델인 OTIPM(Occupational Therapy Intervention Process Model)이라고 하는 하향식(Top-down) 접근의 중재모델을 감각통합의 기능장애를 가지면서 일상의 작업수행에 어려움을 보이는 16세의 청소년에게 적용하여, 감각통합이론의 적용이 작업수행향상에 어떠한 의미를 가지는지 살펴보고자 하였다. 결론: 본 연구에서 적용한 OTIPM의 적용 사례를 통해, 감각통합적인 접근은 클라이언트가 일상에서 수행하기 어려웠던 작업수행에 대한 원인을 추론하는 데 유용하였다. 본 연구의 사례에서 감각통합적인 관점과 접근은 작업수행(Top)에 영향을 주는 기본적인 요소적 문제(Bottom)를 연결하는 첫단계의 중재로써 큰 의미를 가졌고, OTIPM의 적용과정은 클라이언트에게 의미 있는 작업수행을 발견하고 이에 초점을 두어 가장 우선되는 중재를 단계적으로 전개하여, 감각통합치료 이후 실제 작업수행에 초점을 둔 접근을 전개하는 데 유용하였다.

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Fiber post를 이용하여 임플란트 지대주에 보철물을 결합하는 SB-locking method: A case report (SB-locking method for keeping implant restorations mechanically in place using fiber post: A case report)

  • 정민아;이성복;이석원
    • 대한치과보철학회지
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    • 제58권4호
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    • pp.356-362
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    • 2020
  • 강동경희치대병원 보철과에서는 치료계획단계에서 마지막 결과를 미리 형상화하고 그것에 입각하여 치료를 진행하는 Top-Down 개념의 치료접근법을 2006년부터 실행하고 있다. 이번 증례도 그 개념에 입각하여 임플란트 수술에 앞서 미리 최종 보철치료의 방법과 결과를 형상화시켜 놓고 치료를 진행한 실례이다. 임플란트 보철의 여러 방법 중 시멘트 유지방식은 임플란트의 기울기에 구속받지 않고 간단하게 보철물 제작이 가능하나, 접착 후 치은 연하의 잉여 시멘트를 완전하게 제거하기 어렵고, 필요할 때 탈착이 불편하다는 단점이 있다. 따라서 전치부 임플란트 보철수복 시 SB-locking method의 유지방식을 이용하여 시멘트 유지방식의 문제를 해결하면서 심미적인 임플란트 보철수복이 가능했던 증례를 보고하고자 한다.

Integration of top-down and bottom-up approaches for a complementary high spatial resolution satellite rainfall product in South Korea

  • Nguyen, Hoang Hai;Han, Byungjoo;Oh, Yeontaek;Jung, Woosung;Shin, Daeyun
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2022년도 학술발표회
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    • pp.153-153
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    • 2022
  • Large-scale and accurate observations at fine spatial resolution through a means of remote sensing offer an effective tool for capturing rainfall variability over the traditional rain gauges and weather radars. Although satellite rainfall products (SRPs) derived using two major estimation approaches were evaluated worldwide, their practical applications suffered from limitations. In particular, the traditional top-down SRPs (e.g., IMERG), which are based on direct estimation of rain rate from microwave satellite observations, are mainly restricted with their coarse spatial resolution, while applications of the bottom-up approach, which allows backward estimation of rainfall from soil moisture signals, to novel high spatial resolution soil moisture satellite sensors over South Korea are not introduced. Thus, this study aims to evaluate the performances of a state-of-the-art bottom-up SRP (the self-calibrated SM2RAIN model) applied to the C-band SAR Sentinel-1, a statistically downscaled version of the conventional top-down IMERG SRP, and their integration for a targeted high spatial resolution of 0.01° (~ 1-km) over central South Korea, where the differences in climate zones (coastal region vs. mainland region) and vegetation covers (croplands vs. mixed forests) are highlighted. The results indicated that each single SRP can provide plus points in distinct climatic and vegetated conditions, while their drawbacks have existed. Superior performance was obtained by merging these individual SRPs, providing preliminary results on a complementary high spatial resolution SRP over central South Korea. This study results shed light on the further development of integration framework and a complementary high spatial resolution rainfall product from multi-satellite sensors as well as multi-observing systems (integrated gauge-radar-satellite) extending for entire South Korea, toward the demands for urban hydrology and microscale agriculture.

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비즈니스 서비스 식별을 위한 변형 순차패턴 마이닝 알고리즘 (Adapted Sequential Pattern Mining Algorithms for Business Service Identification)

  • 이정원
    • 한국컴퓨터정보학회논문지
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    • 제14권4호
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    • pp.87-99
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    • 2009
  • SOA를 도입하는 하향식 (top-down) 방법은 온톨로지를 기반으로 서비스를 분석하고 설계하는 서비스 모델링 단계를 핵심으로 봄으로써 SOA의 장점을 가장 잘 반영할 수 있는 방법으로 권장되고 있다. 그러나 대부분의 기업들은 하향식 방법이 최상이라는 것을 알면서도 기업 이윤 창출에 단기적인 효과가 드러나지 않고 도입 초기에 개발시간과 비용이 증대되므로 이를 꺼리게 된다. 특히 잘 정의된 컴포넌트 시스템을 이미 사용하고 있는 경우에 더욱 그러하다. 따라서 본 논문에서는 기존의 잘 정의된 컴포넌트시스템을 최대한 이용할 수 있는 상향식 (bottom-up) 서비스식별 방법을 제안한다. GUI는 직접 사용자의 입력을 받아 들여 이벤트를 발생시킨다는 점에 착안하여 이벤트의 경로를 연결하면 비즈니스 프로세스에 근사시킬 수 있다. 따라서 컴포넌트와 상호작용하는 GUI의 이벤트 수를 기준으로 핵심 GUI를 선정하고 핵심 GUI로부터 연결되는 이벤트 경로를 대상으로 기존의 순차패턴 마이닝 알고리즘을 변형하여 사용자의 서비스 사용 패턴을 추출한다. 실험결과 추출된 이벤트 패턴에 응집도를 적용하여 다양한 크기의 비즈니스 서비스를 식별할 수 있음을 보였다.