• Title/Summary/Keyword: 시스템분석 설계

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Development of a Mentorship Education Model for the Gifted of the Science Education Institute (과학영재교육원 사사교육을 위한 모형 개발)

  • Yoon, Ki-Sang;Kim, Beom-Ki
    • Journal of Science Education
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    • v.35 no.1
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    • pp.48-58
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    • 2011
  • This study was performed to develop a model for mentorship education in the science education institute for the gifted. Existing mentorship education models were focused on R&E, which involved science high school students as research participants. For this purpose, a new model was proposed with comparatively definite stages and terms, and based on the theoretical background concerning science inquiry abilities and scientific creativities or the mentorship education in the science education institute for the gifted. Existing mentorship models for science-gifted students were analyzed and compared with the scientific inquiry process and science paper form. A science paper form consisting of four stages was selected. A new model was constructed consisting of six stages, and this model was modified to be made fit for application to students in the physics mentorship course at the science education institute for the gifted in K National University. Good points and improvable points of the model through the application were identified, and the model was modified accordingly. In conclusion, a new model was proposed as a mentorship model for science-gifted students. This model was constructed using the PREPARATION-INTRODUCTION-METHOD-RESULT-CONCLUSION-FINISH format.

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Parametric Study on Wing Design of Insect-mimicking Aerial Vehicle with Biplane Configuration (겹 날개를 사용하는 곤충 모방 비행체의 날개 형상에 대한 파라메트릭 연구)

  • Park, Heetae;Kim, Dongmin;Mo, Hyemin;Kim, Lamsu;Lee, Byoungju;Kim, Inrae;Kim, Seungkeun;Ryi, Jaeha;Choi, Jong-Soo
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.46 no.9
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    • pp.712-722
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    • 2018
  • This paper conducts parametric studies on flapping wing design, one of the most important design parameters of insect-mimicking aerial vehicles. Experimental study on wing shape was done through comparison and analysis of thrust, pitching moment, power consumption, and thrust-to-power ratio. A two-axis balance and hall sensor measure force and moment, and flapping frequency, respectively. Wing configuration is biplane configuration which can develop clap and fling effect. A reference wing shape is a simplified dragonfly's wing and studies on aspect ratio and wing area were implemented. As a result, thrust, pitching moment, and power consumption tend to increase as aspect ratio and area increase. Also, it is found that the flapping mechanism was not normally operated when the main wing has an aspect ratio or area more than each certain value. Finally, the wing shape is determined by comparing thrust-to-power ratio of all wings satisfying the required minimum thrust. However, the stability is not secured due to moment generated by disaccord between thrust line and center of gravity. To cope with this, aerodynamic dampers are used at the top and bottom of the fuselage; then, indoor flight test was attempted for indirect performance verification of the parametric study of the main wing.

Baseline Wander Removing Method Based on Morphological Filter for Efficient QRS Detection (효율적인 QRS 검출을 위한 형태 연산 기반의 기저선 잡음 제거 기법)

  • Cho, Ik-Sung;Kim, Joo-Man;Kim, Seon-Jong;Kwon, Hyeog-Soong
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.1
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    • pp.166-174
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    • 2013
  • QRS detection of ECG is the most popular and easy way to detect cardiac-disease. But it is difficult to analyze the ECG signal because of various noise types. The important problem in recording ECG signal is a baseline wandering, which is occurred by rhythm of respiration and muscle contraction attaching to an electrode. Particularly, in the healthcare system that must continuously monitor people's situation, it is necessary to process ECG signal in realtime. In other words, the design of algorithm that exactly detects QRS region using minimal computation by analyzing the person's physical condition and/or environment is needed. Therefore, baseline wander removing method based on morphological filter for efficient QRS detection method is presented in this paper. For this purpose, we detected QRS through the preprocessing method using morphological filter, adaptive threshold, and window. The signal distortion ratio of the proposed method is compared with other filtering method. Also, R wave detection is evaluated by using MIT-BIH arrhythmia database. Experiment result show that proposed method removes baseline wanders effectively without significant morphological distortion.

Numerical Study on Characteristics of Gas Leakage in an Underground Combined Cycle Power Plant (지하 복합발전 플랜트 내부의 가스 누출 특성에 대한 수치해석 연구)

  • Bang, Joo Won;Sung, Kun Hyuk;Ryou, Hong Sun;Lee, Seong Hyuk
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.5
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    • pp.594-600
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    • 2016
  • The present study numerically investigated the gas leakage characteristics in a simplified underground combined cycle power plant. The effect of obstacles near a crack location on the gas concentration in the confined space was analyzed by using the lower flammable limit (LFL) of methane gas. When the jet flow was close to the vertical walls, the longitudinal leakage distance increased by about 60% (when an obstacles was present) compared to the case without any obstacle, because these obstacles prevented transverse flows. In addition, when an air filter was installed near to the trajectory of the gas flow, the longitudinal leakage distance was similar to the distance between the crack and obstacle, whereas the transverse leakage distance increased up to 8 times compared to the case without any obstacle. As the jet flow impacts on the obstacle and changes its direction, the gas flows recirculate. Therefore, it is necessary to consider the effect of the structure and facility locations on the trajectory of the jet flow to propose an accident prevention system in confined spaces.

GIS spatial D/B formation of geothermal data and Distribution of Heat Flow of Korea (한국의 지열자료 GIS 공간 D/B 구축과 지열류량 분포)

  • Kim, Hyoung-Chan;Lee, Young-Min;Park, Jeong-Min
    • 한국신재생에너지학회:학술대회논문집
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    • 2006.06a
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    • pp.459-460
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    • 2006
  • 현재 남한의 지열류량 측정값으로는 총 363개 지점의 자료가 측정 및 수집되어 있다. 이것은 Mizutani et at. (1970), 장정진 외(1970), 그리고 서정희(1976) 등의 자료, 총 35개의 자료도 추가된 것이다. 1989년 이후부터 측정된 지열류량 자료는 217개 자료이며(임정웅 외, 1989; 임정웅 외, 1996; Lim and Kim, 1997; 염병우 외, 1997), 모두 직접 측정한 것이나, 1989년 이후 보고된 지열류량 자료에 약간의 오류가 있어 이번 연구에서 수정 보완하였다. 또한 과거의 자료 35개 자료는 이미 지열류량 측정치가 논문화 되어 있는 것으로 암석시료는 없다 1989년 이후 2004년까지 자료 217개 2005년도 추가 자료 111개의 지열류량 자료는 암석시료도 있으며, 측정기기가 서로 달라 오차가 있을 수 있어 서로 보정을 해야 할 필요가 있어 시추공 주변 암석을 새로 수집해서 신장비로 다시 측정 보정하였다. 지열류량 D/B 구축은 각 자료의 일련번호, 고유번호 (Sn.), 위경도 좌표 (longitude, lattitude), 암석의 열전도도(thermal conductivity), 지온경사 (thermal gradient), 지열류량 (heat flow)등으로 구성되어 있다. 지열류량 자료 공간 데이터베이스는 점 속성을 가지며 자료형태는 각종 소프트웨어와 호환성이 좋은 shape 파일 형태로 작성하였다. 또만 최근 천부 토양 및 암석 열물성을 이용한 냉난방시스템 즉, Heat Pump System 설계를 위하여 반드시 들어가야 하는 요소인 열확산율, 공극율, 밀도, 비열 등 열물성 특성을 추가하여 GIS 공간 D/B구축하였다. 대륙붕 자료 4개 자료를 제외하고 359개의 지열류량 자료를 이용하여 한반도 남부, 즉 남한의 지열류량 분포도를 작성 분석해 본 결과(그림 1), 우리나라의 지열류량 이상대는 아산만 주변, 보령, 유성, 진안, 울진, 포항, 부산 지역과 포천, 속초, 충주, 수안보 등 지역에서 나타난다 이러한 이상대 주변에는 대개 온천이 발달되어 있었거나 새로 개발되어 있는 곳이다. 온천에 이용하고 있는 시추공의 자료는 배제하였으나 온천이응으로 직접적으로 영향을 받지 않은 시추공의 자료는 사용하였다 이러한 온천 주변 지역이라 하더라도 실제는 온천의 pumping 으로 인한 대류현상으로 주변 일대의 온도를 올려놓았기 때문에 비교적 높은 지열류량 값을 보인다. 한편 한반도 남동부 일대는 이번 추가된 자료에 의해 새로운 지열류량 분포 변화가 나타났다 강원 북부 오색온천지역 부근에서 높은 지열류량 분포를 보이며 또한 우리나라 대단층 중의 하나인 양산단층과 같은 방향으로 발달한 밀양단층, 모량단층, 동래단층 등 주변부로 NNE-SSW 방향의 지열류량 이상대가 발달한다. 이것으로 볼 때 지열류량은 지질구조와 무관하지 않음을 파악할 수 있다. 특히 이러한 단층대 주변은 지열수의 순환이 깊은 심도까지 가능하므로 이러한 대류현상으로 지표부근까지 높은 지온 전달이 되어 나타나는 것으로 판단된다.

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Trajectory Index Structure based on Signatures for Moving Objects on a Spatial Network (공간 네트워크 상의 이동객체를 위한 시그니처 기반의 궤적 색인구조)

  • Kim, Young-Jin;Kim, Young-Chang;Chang, Jae-Woo;Sim, Chun-Bo
    • Journal of Korea Spatial Information System Society
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    • v.10 no.3
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    • pp.1-18
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    • 2008
  • Because we can usually get many information through analyzing trajectories of moving objects on spatial networks, efficient trajectory index structures are required to achieve good retrieval performance on their trajectories. However, there has been little research on trajectory index structures for spatial networks such as FNR-tree and MON-tree. Also, because FNR-tree and MON-tree store the segment unit of moving objects, they can't support the trajectory of whole moving objects. In this paper, we propose an efficient trajectory index structures based on signatures on a spatial network, named SigMO-Tree. For this, we divide moving object data into spatial and temporal attributes, and design an index structure which supports not only range query but trajectory query by preserving the whole trajectory of moving objects. In addition, we divide user queries into trajectory query based on spatio-temporal area and similar-tralectory query, and propose query processing algorithms to support them. The algorithm uses a signature file in order to retrieve candidate trajectories efficiently Finally, we show from our performance analysis that our trajectory index structure outperforms the existing index structures like FNR-Tree and MON-Tree.

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Development of an Edge-based Point Correlation Algorithm Avoiding Full Point Search in Visual Inspection System (전탐색 회피에 의한 고속 에지기반 점 상관 알고리즘의 개발)

  • Kang, Dong-Joong;Kim, Mun-Jo;Kim, Min-Sung;Lee, Eung-Joo
    • The KIPS Transactions:PartB
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    • v.11B no.3
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    • pp.327-336
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    • 2004
  • For visual inspection system in real industrial environment, it is one of most important tasks to design fast and stable pattern matching algorithm. This paper presents an edge-based point correlation algorithm avoiding full search in visual inspection system. Conventional algorithms based on NGC(normalized gray-level correlation) have to overcome some difficulties for applying to automated inspection system in factory environment. First of all, NGC algorithms need high time complexity and thus high performance hardware to satisfy real-time process. In addition, lighting condition in realistic factory environments if not stable and therefore intensity variation from uncontrolled lights gives many roubles for applying directly NGC as pattern matching algorithm in this paper, we propose an algorithm to solve these problems from using thinned and binarized edge data and skipping full point search with edge-map analysis. A point correlation algorithm with the thinned edges is introduced with image pyramid technique to reduce the time complexity. Matching edges instead of using original gray-level pixel data overcomes NGC problems and pyramid of edges also provides fast and stable processing. All proposed methods are preyed from experiments using real images.

Study of Factors for development of Advanced Media filter for Ballast water Treatment (밸러스트 수 처리용 메디아 필터 개발을 위한 여과특성에 관한 연구)

  • Park, Seon-Jeong;Lim, Jae-Dong;Kim, Dong-Geun;Kim, In-Soo
    • Journal of Navigation and Port Research
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    • v.32 no.6
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    • pp.499-503
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    • 2008
  • As the conference result of MEPC in IMO, development of ballast water management system corresponding to newly established ballast water management standard (D2 regulation) of shipping is being made an active progress over the whole world. The ballast water management system should treat particular material of more than $10{\mu}m$ in high capacity of more than 500t per hour in the event of filtration process. Also, it is very difficult to develop a practical management system since a limited element which a narrow space of the ship should be designed in the minimal volume is assumed. Therefore, the study promoted a study on the next generation auto back wash media filter to overcome such a limited element. Also, the study performed pressure and flux measurement test followed by thickness of each filter medium for filtration by each size to grasp a relation between absorption and pressure at the time of vacuum filtration and mechanical analysis and turbidity change observation of filtered water after vacuum filtration.

Numerical Analysis of Phase Behavior and Flow Properties in an Injection Tubing during Gas Phase CO2 Injection : Application of Demonstration-scale Offshore CO2 Storage Project in the Pohang Basin, Korea (기체상태의 CO2 주입시 주입관내 상변화 및 유동 특성의 수치해석적 연구 : 포항분지 해상 중소규모 CO2 지중저장 사업에 적용)

  • Jung, Woodong;Sung, Wonmo;Han, Jeong-Min;Song, Youngsoo;Wang, Jihoon
    • Journal of the Korean Institute of Gas
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    • v.25 no.4
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    • pp.10-18
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    • 2021
  • CO2 storage technology in an aquifer is one of the most effective way to decrease global warming due to a high storage capacity and economics. A demonstration-scale offshore CO2 storage project was performed in a geological deep aquifer in the Pohang Basin, Korea for a technological development of large-scale CO2 storage. A challenging issue in the early design stage of the project was to establish the proper injectivity during CO2 injection. To solve this issue, injection conditions were calculated by calculating injection rate, pressure, temperature, CO2 phase change, and thermodynamic properties. For this study, we simulated and numerically analyzed CO2 phase change from gas to supercritical phase and flow behavior in transport piping and injection tubing using OLGA program. Our results provide the injectivity conditions of CO2 injection system combined with a bottomhole pressure of an aquifer.

Consequence Analysis of Hydrogen Filling Stations based on Cascade Compressing Systems (케스케이드 방식 압축시스템 기반의 수소충전소에 대한 정성적 위험성평가)

  • Ahn, Byeong-Jun;Rhim, Jong-Kuk
    • Journal of the Korean Institute of Gas
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    • v.25 no.2
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    • pp.13-21
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    • 2021
  • Because of the recent expansion of hydrogen vehicle supply, the installation of hydrogen filling station is expected to gradually expand. This study attempts to predict the damage scale and propose a safer design form based on the scenario that assumes the worst case of a hydrogen station. A Flacs solver using computational fluid dynamics (CFD) was used to predict the damage scale, and the accuracy was verified by comparing it with the experimental results of previous researchers. The damage scale prediction was conducted for hydrogen leakage and explosion, and the prediction target was the KR model based on the measured values. And as a comparative review model, a roofless model was selected without a ceiling. As a result of analyzing the two models, it was possible to confirm the accumulation and retention of hydrogen gas up to 60 vol% or more in the KR model, whereas in the case of the Roofless model, the phenomenon of discharge and diffusion to the outside of the charging station by riding the wall after leakage. I was able to check. In conclusion, it was reviewed that the type of hydrogen charging station without ceiling is more advantageous for safety than the hydrogen filling station model.