• 제목/요약/키워드: 1st-order system

검색결과 419건 처리시간 0.026초

월경통 치료 전과 후의 적외선체열영상 및 피부저항변이도 변화에 대한 연구 (A Study on the Change of Digital Infrared Thermographic Imaging and Skin Resistance Variability before and after Treatment of Dysmenorrhea)

  • 김현주;이용현;손영주
    • 대한한방부인과학회지
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    • 제26권2호
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    • pp.88-103
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    • 2013
  • Purpose: The aim of this study was to examine the effect of oriental diagnosis and treatment for dysmenorrhea patients on lower abdominal temperature and Skin Resistance Variability(SRV). Methods: We studied twenty-five dysmenorrhea patients, who visited Oriental Medicine Hospital of ${\bigcirc}{\bigcirc}$ University for 10 months(Sep. 2011~Jun. 2012). Patients with organic disease such as endometriosis, uterine myoma and pelvic inflammatory disease were excluded from this study. We prescribed 3 types of treatments, herbal medicine, acupuncture, and moxibustion, for one menstrual cycle. Digital Infrared Thermographic Imaging(DITI), 7-Zone-Diagnostic System(CP-6000A), VAS(Visual analog scale) and MVRS(Multidimensional verbal rating scale) were conducted before and after the treatment. The result of DITI, 7-Zone-Diagnostic System, VAS and MVRS before and after treatment were compared in order to objectively assess the therapeutic effect. Results: When we compared the results of DITI, CV4 temperature after treatment was increased compared with that of before, and temperature difference between CV12 and CV4 after treatment was decreased compared with that of before. But there was no significant difference. When we compared the results of 7-Zone-Diagnostic System at 1st and 2nd trial, the height of 1~5 area was lower than that of before. And at 1st and 2nd trial, the height of 6, 7 area was higher than that of before, but there were no significant difference in most. When we compared the results of VAS and MVRS, VAS and MVRS after treatment was significantly decreased compared with that of before(p<0.01). Conclusions: This study shows that oriental diagnosis and treatment for dysmenorrhea patients affects the results of DITI. Further study will be needed.

Guidance Synthesis to Control Impact Angle and Time

  • Shin, Hyo-Sang;Lee, Jin-Ik;Tahk, Min-Jea
    • International Journal of Aeronautical and Space Sciences
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    • 제7권1호
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    • pp.129-136
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    • 2006
  • A new guidance synthesis for anti-ship missiles to control impact angle and impact time is proposed in this paper. The flight vehicle is assumed as a 1st order lag system to consider more practical system. The proposed guidance synthesis enhances the survivability of anti-ship missiles because multiple anti-ship missiles with the proposed synthesis can hit the target simultaneously. The control input to satisfy constraints of zero miss distance and impact angle, and the feedforward bias control input to control impact time constitute the guidance law. The former is from trajectory shaping guidance, the latter is from neural network. And particle swarm optimization method is introduced to furnish reference input and output for learning in neural network. The performance of the proposed synthesis in the accuracy of impact time and angle is validated by numerical examples.

멀티버너 보일러용 열교환기 모듈 특성 시험 - 모듈 순서에 따른 특성결과 - (Experimental Study on Thermal Characteristics of Heat Exchanger Modules for Multi Burner Boiler)

  • 강새별;김종진;안준
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회B
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    • pp.3053-3058
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    • 2008
  • We develop a heat exchanger modules for a multi-burner boiler. The heat exchanger module is kind of a heat recovery steam generator (HRSG). This heat recovery system has 4 heat exchanger modules. The 1st module consists of 27 bare tubes due to high temperature exhaust gas and the others consist of 27 finned tubes. The maximum steam pressure of each module is 1 MPa and tested steam pressure is 0.7 MPa. In order to test these heat exchanger modules, we make a 0.5t/h flue tube boiler (LNG, $40\;Nm^3/h$). We tested the heat exchanger module with changing the position of each heat exchanger module. We measured the inlet and outlet temperature of each heat exchanger module and calculated the heat exchange rate. The results show that if module C is placed at second stage (the 1st stage is always module O, bare tube module), there is no need to attach an additional heat exchanger module. In this case the exit temperature of module C is low enough to enter an economizer which is more effective in heat recovery than a heat exchanger module.

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북극해 하계 남동 바렌츠 해역에서 식물플랑크톤 크기별 분포와 환경요인에 관한 연구 (Phytoplankton and Environmental Factors in the Southeastern Barents Sea during August 2003)

  • 주형민;이진환;정경호;강재신;강성호
    • Ocean and Polar Research
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    • 제27권3호
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    • pp.265-276
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    • 2005
  • In order to grasp the structure and dynamics of phytoplankton communities, chlorophyll-a (Chl-a) and cell abundance were measured at 20 stations during the period from August 9 to August 21, 2003 in the southeastern Barents Sea on surface and subsurface chlorophyll maximum depth (SCM). Surface temperatures were varied from minimum $-0.7^{\circ}C(st. 18)$ to maximum $10.4^{\circ}C(st.1)$. Salinities were varied from minimum 29.9 psu(st. 18) to maximum 35.8 psu(st.2). The maximum nutrient(phosphate, nitrate, silicate) concentrations were $0.12{\mu}M,\;0.11{\mu}M,\;7.53{\mu}M$ and minimum concentrations were $0.01{\mu}M,\;0.03{\mu}M,\;1.43{\mu}M$, respectively. On SCM physical environmental factor were almost similar. Chl-a concentrations ranged from 0.23 to $2.13{\mu}g\;chi-a\;l^{-1}$ at SCM. Nano- and pico phytoplankton were the important contributors for increase of the Chl-a. It was about seven times difference between highest concentration to lowest. Phytoplankton communities were composed of diatoms, dinoflagellates, cryptophyceae, silicoflagellate, and prymnesiophyceae showing 37 taxa at surface and 38 taxa at SCM. Picophytoplankton was the most dominant in all stations and all layers, but the second groups were 2 and/or 3 taxa. Phytoplankton abundance ranged from minimum $4.3{\times}10^5\;cells\;l^{-1}$ (st. 20) to maximum $2.4{\times}10^6\;cells\;l^{\-1}$. (st. 17) at surface water. As a result, phytoplankton might be controlled by physical factors such as North Atlantic ocean currents and northern melt water among environmental factors in Barents Set h addition the dominant species were nano- and pico phytoplankton such as Phaeocystis, Cryptomonas and Dinobryon in the study area.

금강 지류 백곡천의 어류군집 및 천연기념물 미호종개 Cobitis choii의 서식양상 (Community Structure of Fish and Inhabiting Status of Natural Monument Cobitis choii in the Baekgok Stream, a Tributary of the Geum River Drainage Systrem of Korea)

  • 고명훈;홍양기;김해림;방인철
    • 한국어류학회지
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    • 제26권2호
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    • pp.99-111
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    • 2014
  • 금강 지류인 충북 진천군 백곡천의 어류군집 및 멸종위기종 미호종개의 서식양상을 밝히기 위하여 2012년 조사를 실시하였다. 상류 (St. 1~3)는 하천형이 계곡형인 Aa 또는 Aa-Bb형이고 하상은 주로 큰돌과 돌로 이루어져 있었으며 10~14종의 어류가 서식하고 있었고, 중류 (St. 4~5)는 중류형인 Bb형 또는 Bb-Bc형으로 하상은 돌과 큰돌, 자갈로 이루어져 있었으며 15~21종의 어류가 서식하고 있었다. St. 6은 백곡저수지로 하상은 대부분 펄이었고 9종이 서식하고 있었으며, St. 7은 백곡저수지 유출지점으로 하천형이 Aa-Bb형이고 하상은 주로 큰돌과 돌로 이루어져 있었으며 7종이 채집되었다. 하류(St. 8~9)는 중류형인 Bb형으로 하상은 주로 돌과 모래로 이루어져 있었으며 20~23종의 어류가 서식하고 있었다. 백곡천에 출현한 종수는 모두 10과 35종이었으며, 우점종은 피라미(34.7%)였고, 아우점종은 돌고기(9.4%)와 돌마자(9.0%)였으며, 그 다음으로 민물검정망둑(8.2%), 모래무지(5.9%), 붕어(4.6%), 참몰개(3.7%), 밀어(3.0%) 순으로 우세하게 출현하였다. 출현종 중 고유종은 10종 (28.6%)이었으며, 외래어종은 떡붕어와 배스 2종이었다. 천연기념물이며 멸종위기종인 미호종개는 St. 5의 유속이 느리고 수심 0.3~1.0 m이며 하상이 모래인 곳에 주로 서식하고 있었다. 이들의 생태적 특징을 조사한 결과 서식개체수는 $7,838{\pm}6,290$개체가, 연령은 당년생 전장 38~45 mm, 1년생 46~60 mm, 2년생 61~80 mm, 3년생 이상은 81~93 mm로 추정되었고, 비만도지수 (${\times}10^5$)는 암컷 0.36~0.39, 수컷 0.35~0.38이었으며, 기생충의 일종인 이생충(digenea)이 13.5%가 감염되어 있었다. 그 밖에 백곡천 미호종개의 건강성과 위협요인, 보전에 대해 논의하였다.

Absolute Stability Margins in Missile Guidance Loop

  • Kim, Jong-Ju;Lyou, Joon
    • International Journal of Control, Automation, and Systems
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    • 제6권3호
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    • pp.460-466
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    • 2008
  • This paper deals with the stability analysis of a missile guidance loop employing an integrated proportional navigation guidance law. The missile guidance loop is formulated as a closed-loop control system consisting of a linear time-invariant feed-forward block and a time-varying feedback gain. Based on the circle criterion, we have defined the concept of absolute stability margins and obtained the gain and phase margins for the system assuming 1 st order missile/autopilot dynamics. The correlation between the absolute stability margins and the margins derived from the frozen system analysis is also discussed.

초정밀 스테이지 설계 및 제어 시스템에 관한 연구 (A study of the design and control system for the ultra-precision stage)

  • 박종성;정규원
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2005년도 춘계학술대회 논문집
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    • pp.54-59
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    • 2005
  • Recently, the ultra-precision stage is widely used in the fields of the nano-technology, specially in AFMs(Atomic Force Microscope) and STMs(Scanning Tunneling Microscope). In this paper, the ultra-precision stage which consists of flexure hinges, piezoelectric actuator, and ultra-precision linear encoder, is designed and developed. The guide mechanism which consisted of flexure hinges is analyzed by Finite Element Method. And we derived the transfer function of the system in 1st order system from step responses according to the magnitude. We performed simulation for the model to tune the control gain and applied the gains to the developed system. Experimental results found that the stage can be controlled in 5 nm resolution by PID controller.

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이식형 양심실 보조 장치에 사용된 기계식 판막의 음향 스펙트럼 특성 (Spectral Properties of the Sound From the Mechanical Valve Employed in an Implantable Biventricular Assist Device)

  • 최민주;이서우;이혁수;민병구
    • 대한의용생체공학회:의공학회지
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    • 제22권5호
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    • pp.439-448
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    • 2001
  • 이식형 양심실 보조 장치 (Biventricular Assist Device, BVAD)에서 판막이 닫힐 때 나는 소리의 특성과 판막의 물리적인 상태의 상관성을 고찰하였다. 본 연구에서 Bj rk Shiley Convexo Concave tilting disk 판막을 사용했으며, 모의 순환계와 양의 체내에서 동작하는 BVAD 에서 판막음을 측정하였다. 모의 순환계에서는 정상 판막. 기계적으로 손상된 판막. 모의 혈전이 형성된 판막의 3가지를 고려하였다. 양에 이식된 BVAD의 경우, 이식 후 1일부터 5일 동안 규칙적인 간격으로 판막음을 측정하였다. 측정된 신호의 스펙트럼 특성은 Multiple Signal Classification (MUSIC)을 이용하여 추정하였다. MUSIC의 최적 차수는 Bayesian Information Criterion (BIC)을 이용하여 계산하였다. 실험 결과, 판막의 기계적인 손상은 판막 폐쇄음의 주파수 스펙트럼 구조를 변화시키고 있으며, 혈전의 형성은 판막음 스펙트럼의 기본 구조는 유지하지만 피크 주파수와 에너지의 크기를 변화시키는 것으로 관찰되었다. 최대 에너지를 가지는 MSP (maximum spectral peak)는 정상 판막에서는 2 kHz에 위치하고 있으나 모의 혈전을 부탁한 판막에서는 3 kHz로 이동하였다. 손상된 판막은 7 kHz 부근에서 강한 피크 보이고 있다 실험 동물 내에서 판막에 혈전이 형성되어감에 따라 판막음은 저주파 성분 (〈 2kHz)이 상대적으로 크게 감소하였고, Ist 2nd. 3rd MSP 주파수는 약간씩 상승하였다. 또한 혈전이 형성되어 감에 따라 반복해서 측정된 판막음의 1st, 2nd. 3rd MSP 주파수의 변화 정도 및 BIC 차수는 감소하는 것으로 나타났다

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계단식 관측기에 의한 수중 차의 상태추정 (State Estimation for Underwater Vehicles by Means of Cascade Observers)

  • 김동헌
    • 한국지능시스템학회논문지
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    • 제19권2호
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    • pp.168-173
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    • 2009
  • 본 논문은 수중 차의 차속도와 프로펠러 각속도를 추정하는 문제를 다룬다. 계단식 관측기는 측정된 위치 값으로부터 속도값 추정을 위해 사용한다. 고이득 관측기(high-gain observer)에 전형적으로 생기는 전형적인 문제를 없애기 위하여 계단식 구조의 관측기가 설계되었다. 고이득 관측기처럼 시스템 다이나믹스와 파라미터로부터 무관하게 설계할 수 있으며 단순한 구조를 가진다 관측기의 첫 단계에서 출력 값이 추정되고 측정된 출력의 1계 미분 값이 관측기의 두 번째 단계를 통해 추정된다. 또한 출력의 n 번째 미분 값은 관측기의 n+1 번째 단계에서 추정된다. 제안된 관측기가 전체 점근적 안정도를 보장함을 보여준다. 시뮬레이션 결과는 기존의 고이득 관측기에 비해 제안된 관측기가 수중 차의 차속도와 프로펠러 각속도를 더 우수하게 추정함을 보여준다.

양문형 냉장고 냉동실 결빙원인해석 및 최소화 방안 (Investigation on Freezing in the Freezing Compartment of a Side by Side Refrigerator)

  • 김윤규;정호윤;최윤환;이연원
    • 동력기계공학회지
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    • 제14권1호
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    • pp.34-39
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    • 2010
  • A side by side refrigerator is popularly used one among electric home appliances according to the rise of the customer's living standard. But the frost problem in freezing compartment comes out whenever we develop the high quality refrigerator. In this research, internal flow simulation and temperature measurement were carried out by using CFD and T-type thermocouple respectively in order to understand freezing mechanism. It was revealed that the amount of frost beneath the 1st and 2nd shelves is approximately 40% of total frost and the cause of frost generation is due to bad circulation of low speed cold flow. Using this analysis, the shapes of outlets under shelves are modified. So, the amount of frost in this modified model decreases 6% comparing to original one.