• Title/Summary/Keyword: 1st-Order System

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

  • Kim, Hyeon-Ju;Lee, Yong-Hyun;Sohn, Young-Joo
    • The Journal of Korean Obstetrics and Gynecology
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    • v.26 no.2
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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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    • v.7 no.1
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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.

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

  • Kang, Sae-Byul;Kim, Jong-Jin;Ahn, Joon
    • Proceedings of the KSME Conference
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    • 2008.11b
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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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Phytoplankton and Environmental Factors in the Southeastern Barents Sea during August 2003 (북극해 하계 남동 바렌츠 해역에서 식물플랑크톤 크기별 분포와 환경요인에 관한 연구)

  • Joo, Hyoung-Min;Lee, Jin-Hwan;Chung, Kyung-Ho;Kang, Jae-Shin;Kang, Sung-Ho
    • Ocean and Polar Research
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    • v.27 no.3
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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.

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 (금강 지류 백곡천의 어류군집 및 천연기념물 미호종개 Cobitis choii의 서식양상)

  • Ko, Myeong-Hun;Hong, Yang-Ki;Kim, Hae-Lim;Bang, In-Chul
    • Korean Journal of Ichthyology
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    • v.26 no.2
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    • pp.99-111
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    • 2014
  • Community structure of fish and inhabiting status of natural monument and endangered species, Cobitis choii were investigated in the Baekgok Stream, a tributary of the Geum River drainage system of Korea from May to November 2012. Ten-15 fish species inhabited upper stream (St. 1~St. 3) with a Aa or Aa-Bb river type composed of mostly pebble and cobble bottoms. 15~21 species did middle stream (St. 4~St. 5) with Aa or Aa-Bb type composed of mostly cobble, boulder and pebble bottoms. Nine species did Reservoir Baekgok (St. 6) with composed of mostly mud bottoms, and Seven species did Reservoir Baekgok outflow (St. 7) with Aa-Bb type composed of mostly boulder and cobble bottoms. And 20~23 species did lower stream (St. 8~St. 9) with a Bb-Bc type composed of mostly cobble and sand bottoms. A total of 35 species belonging to ten families were found in the stream during the survey. The dominant species were in the order of Zacco platypus (34.7%), Pungtungia herzi (9.4%) and Microphysogobio yaluensis (9.0%). Other abundant species included Tridentiger bifasciatus (8.2%), Pseudogobio esocinus (5.9%), Carassius auratus (4.6%), Squalidus chankaensis tsuchigae (3.7%), Rhinogobius brunneus (3.0%). Among residing species, ten (28.6%) species were endemic to Korea, one (Cobits choii) was endangered, and two (Micropterus salmoides and C. cuvieri) were non-indigenous. Natural monument and endangered species, C. choii were only inhabited St. 5, and they are inhabited 30~100 cm in water depth, sand bottom and slowly velocity. Using the mark-recapture method, populations were estimated at $7,838{\pm}6,290$ individuals. Age group in May estimated from total length indicated that the 38~45 mm group is 0 year old, the 46~60 mm group is 1 years old, the 61~80 mm group is 2 years old, and the 81~93 mm group is more than 3 years old. Condition factor (${\times}10^5) was 0.36~0.39 and 0.35~0.38 for female and male, respectively, and they are 13.5% were infected with parasites (digenea). We are discussed the health status, threats and conservation strategies of C. choii in the Baekgok Stream.

Absolute Stability Margins in Missile Guidance Loop

  • Kim, Jong-Ju;Lyou, Joon
    • International Journal of Control, Automation, and Systems
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    • v.6 no.3
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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.

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

  • Park Jongsung;Jeong Kyuwon
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2005.05a
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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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Spectral Properties of the Sound From the Mechanical Valve Employed in an Implantable Biventricular Assist Device (이식형 양심실 보조 장치에 사용된 기계식 판막의 음향 스펙트럼 특성)

  • 최민주;이서우;이혁수;민병구
    • Journal of Biomedical Engineering Research
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    • v.22 no.5
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    • pp.439-448
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    • 2001
  • This paper considers the acoustical characteristics of the closing click sounds of the mechanical valves employed in an implantable biventricular assist device (BYAD) and their re1evance to the Physical states of the valved. Bj rk Shiley Convexo Concave tilting disk valve was chosen for the study and acoustic measurement was made for the BYAD operated in a mock circulatory system as well as implanted in an animal (sheep). In the BYAD operated in the mock circulatory system. three different states of the valve were examined, ie. normal. mechanically damaged. pseudo-thrombus attached. Microphone measurement for the BVAD implanted in the animal was carried out for five days at a regular time interval from one day after implantation. Characteristic spectrum of the sound from the valve was estimated using Multiple Signal Classification (MUSIC) in which the optimal order was determined according to Bayesian Information Criterion (BIC) . It was observed that the mechanical damage of the valve resulted in changes of the structure of the acoustic spectrum. In contrast. the thrombus formed on the valve did not change much the basic structure of the spectrum but brought about altering the spectral Peak frequencies and energies. Maximum spectral Peak (MSP) with the greatest energy was seen at 2 kHz for the normal valve and it was shifted to 3 kHz for the calve attaching the Pseudo-thrombus. Unlike the normal valve, strong spectral Peak appeared around 7 kHz in the sound from the valve mechanically damaged. In the case of the BYAD implanted in the animal. as the thrombus grew, acoustic energy was reduced relatively more in the low frequency components (〈 2 kHz) and the frequencies of the 1st, 2nd and 3rd MSP were increased little. The thrombus formation would result in reduction in both the variability of the 1st, 2nd and 3rd MSP and the value of the BIC optimal order.

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

  • Kim, Dong-Hun
    • Journal of the Korean Institute of Intelligent Systems
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    • v.19 no.2
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    • pp.168-173
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    • 2009
  • This paper investigates the estimation problem of vehicle velocity and propeller angular velocity on the underwater vehicle. Inspired by but different from a high-gain observer, the cascade observer features a cascade structure and adaptive observer gains. In doing so the cascade observer attempts to overcome some of the typical problems that may pose to a high-gain observer. As in the case of a high-gain observer, the cascade observer structure is simple and universal in the sense that it is independent of the system dynamics and parameters. A cascade observer is used for the estimation of velocity from measured position. In the 1st step of the observer, the output is estimated, and the 1st order derivative of measured output is estimated via the 2nd step of the observer. Also, nth order derivative of the output is estimated in the (n+1)th step of the observer. It is shown that the proposed observer guarantees globally asymptotical stability. By simulation results, the proposed observer scheme for the estimations of vehicle velocity and propeller angular velocity shows better performance than the scheme based on the existing observer.

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

  • Kim, Y.K.;Jung, H.Y.;Choi, Y.H.;Lee, Y.W.
    • Journal of Power System Engineering
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    • v.14 no.1
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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.