• Title/Summary/Keyword: condition (A)

Search Result 53,717, Processing Time 0.065 seconds

A Study on the Effect of Inlet Boundary Condition on Flow Characteristics of a Supersonic Turbine

  • Shin, Bong-Gun;Kim, Kui-Soon;Kim, Jin-Han
    • International Journal of Aeronautical and Space Sciences
    • /
    • v.6 no.1
    • /
    • pp.1-7
    • /
    • 2005
  • The inlet boundary condition of computations about the supersonic turbine flow is commonly applied as far-field inlet boundary condition with specified velocity. However, the inflow condition of supersonic turbine is sometimes affected by the shocks or expansion waves propagated from leading edges of blade. These shocks and expansion waves alter the inlet boundary condition. In this case, the inlet boundary condition can not be specified Therefore, in this paper, numerical analyses for three different inlet conditions - fa-field inlet boundary condition, inlet boundary condition with a linear nozzle and inlet boundary condition with a converging-diverging nozzle - have been performed and compared with experimental results to solve the problem. It is found that the inlet condition with a linear nozzle or a converging-diverging nozzle can prevent changing of inlet boundary condition, and thus predict more accurately the supersonic flow within turbine cascade than a far-field inlet boundary condition does.

A MONOID OVER WHICH ALL CYCLIC FLAT RIGHT S-ACTS SATISFY CONDITION (E)

  • L. Moon, Eun-Ho
    • Journal of applied mathematics & informatics
    • /
    • v.26 no.1_2
    • /
    • pp.395-400
    • /
    • 2008
  • Although the properties of flatness and condition (E) for Sacts over a monoid S are incomparable, Liu([10]) showed that necessary and sufficient condition for a monoid S over which all left S-acts that satisfy condition (E) are flat is the regularity of S. But the problem of describing a monoid over which all cyclic flat left S-acts satisfy condition (E) is still open. Thus the purpose of this paper is to characterize monoids over which all cyclic flat right S-acts satisfy condition (E).

  • PDF

The Effects of Vocabulary Exercises on EFL Vocabulary Learning and Retention

  • Son, Jung-Mi
    • English Language & Literature Teaching
    • /
    • v.13 no.4
    • /
    • pp.167-192
    • /
    • 2007
  • This study investigates the effects of written vocabulary exercises on lexical knowledge. Korean university students learning English as a foreign language were randomly assigned to one of four conditions-Condition 1 (having students match word form with word meaning), Condition 2 (having students fill in the blank provided with a list of words), Condition 3 (having students write sentences with the target words), Condition 4 (having students do three practices with the same vocabulary exercise as the condition 1). Each type of exercises in Condition 1, 2, and 3 was designed to classify a different level of mental processing except Condition 4 with multiple encounters of the target words. Learners' vocabulary knowledge of this study was obtained using a format adopted from the Vocabulary Knowledge Scale (VKS) immediately and two weeks later. The findings indicated that: (1) Condition 4 having students do three matching vocabulary exercises was as effective as the condition 3 (one writing exercise) on the immediate learning of word; (2) although there was no significant difference of the effect of vocabulary exercises between Condition 3 and 4, Condition 4 asking students to do three matching vocabulary exercises was the most effective way of vocabulary retention after two weeks.

  • PDF

Comparison a Forest Fire Spread variation according to weather condition change (기후조건 변화에 따른 산불확산 변화 비교)

  • Lee, Si-Young;Park, Houng-Sek
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
    • /
    • 2008.11a
    • /
    • pp.490-494
    • /
    • 2008
  • We simulated a forest fire which was occurred in Yangyang area on 2005 and compared a results between two different weather conditions(real weather condition and mean weather condition since 1968) using FARSITE, which is a forest fire spread simulator for preventing and predicting fire in USDA. And, we researched a problem in the transition for introducing, so we serve the basic method for prevention and attacking fire. In the result, severe weather condition on 2005 effected a forest fire behavior. The rate of spread under real weather condition was about 4 times faster than mean weather condition. Damaged area was about 10 time than mean weather condition. Therefore, Climate change will make a more sever fire season. As we will encounter to need for accurate prediction in near future, it will be necessary to predict a forest fire linked with future wether and fuel condition.

  • PDF

A Study on Pulse Condition of Sameumsamyang(三陰三陽) in "Hwangjenaegyeong(黃帝內經)" ("황제내경(黃帝內經)"의 삼음삼양(三陰三陽) 맥상(脈象)에 대한 소고(小考))

  • Baik, You-Sang
    • Journal of Korean Medical classics
    • /
    • v.21 no.3
    • /
    • pp.119-125
    • /
    • 2008
  • Among the various pulse diagnosis contents in "Hwangjenaegyeong(黃帝內經)", we researched the pulse conditions that are belonged to Sameumsamyang(三陰三陽), and made a comparative study with pulse conditions of five organs[五臟], that of six meridians in "Sanghallon(傷寒論)". So from now on, this study would make help to understand standard pulse condition of Sameumsamyang(三陰三陽) diseases for clinical application. In "Hwangjenaegyeong(黃帝內經)", pulse condition of Taeyang(太陽) is expressed to be floating, Yangmyeong(陽明)'s condition to be strong but with a little bit weakness, Soyang(少陽)'s condition to be intermediate between Eum(陰) and Yang(陽), Taeeum(太陰)'s condition to be low and soft, So-eum(少陰)'s condition to be low and weak with some occasional upward tendency, Gweoleum(厥陰)'s condition to be mixed state of Eum and Yang.

  • PDF

Velocity Estimation of a Compass Gait Biped Robot by Using Impact Condition and Initial Condition Reset (충돌 조건과 초기치 리셋을 이용한 컴퍼스 이족 로봇의 속도 추정)

  • Son, Young-Ik
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.58 no.11
    • /
    • pp.2266-2268
    • /
    • 2009
  • In this paper, a simple method of angle velocity estimation is presented for a passive dynamic biped robot. The estimation problem is not an easy task because its dynamic model is a hybrid system involved with an impact condition. Instead of designing a complex observer for hybrid systems we simply utilize the impact condition to reset the initial condition of the high-pass filter when the non-support leg hits the slope. The approach has been verified by simulation results.

Comparison of Germination Characteristics and Daily Seed Germination Pattern in 15 New Cultivars of Kentucky Bluegrass under Alternative and Natural Conditions at Room Temperature (자연실온 및 변온환경에서 15종류의 켄터키 블루그래스 신품종의 발아특성 및 일일발아패턴 비교)

  • Kim, Kyoung-Nam
    • Journal of the Korean Society of Environmental Restoration Technology
    • /
    • v.17 no.5
    • /
    • pp.1-17
    • /
    • 2014
  • Research was initiated to investigate early establishment characteristics and germination pattern of Kentucky bluegrass (KB, Poa pratensis L.) under natural room temperature and to analyze differences between alternative and natural conditions for a practical application. Fifteen cultivars of KB were evaluated in the study. Daily and cumulative germination pattern were measured and analyzed on a daily basis. Differences were observed in germination percentage, germination pattern, days to the first germination and days to 75% germination. Germination percentage was variable with cultivars at the end of study. It was 75.75 to 90.25% under natural condition. There were considerable variations in early germination characteristics and germination pattern among KB cultivars according to germination conditions. The first germination in all entries tested was initiated between 6 and 9 DAS (days after seeding) under ISTA (International Seed Testing Association) condition. But it was observed between 9 and 12 DAS under natural condition, being 3 to 5 days later as compared with ISTA condition. On the first date of a germinating process, the germination rate was 0.25% to 25.00% under ISTA condition, while 0.50% to 13.25% under natural condition. Days to the 75% germination were 15.08 to 28.80 DAS under ISTA condition and 17.78 to 28.75 DAS under natural condition. Midnight II, Excursion and Midnight were the fastest cultivars under ISTA condition, while Odyssey the fastest one under natural condition. Regardless of germination condition, the slowest cultivar was Voyager II, being over 4 weeks to 75% germination percentage. For the most cultivars, days to 75% germination under natural room temperature condition were 1 to 8 days slower than under ISTA condition. From this study information on differences in germination characteristics and pattern among cultivars would be usefully applied for KB establishment such as golf course construction. Prior to on-site seeding, a comprehensive germination test is practically recommended due to a possible decline in germination capability during domestic distribution and storage after import.

Stability of the Robot Compliant Motion Control - Part II : Implementation

  • Kim, Sung-Kwun
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1988.10b
    • /
    • pp.1006-1013
    • /
    • 1988
  • We have shown how unstructured modeling was used to derive a general stability condition in Part 1. In Part 2, we focus on the particular dynamics (structures modeling) of the robot manipulator and environment. Using rigid body dynamics, the stability condition for the direct drive robots has been achieved in terms of the Jacobian and robot tracking controller. Combining the structured and unstructured modeling, a stability condition for a particular application can be obtained. This approach has been used to analyze compliant motion on the University of Minnesota robot using a feedforward torque controller. We have obtained a stability condition for this application. Through both simulation and experiment, the sufficiency of this condition has been demonstrated. For a sufficient stability condition, recall that if the condition is satisfied, then the stability is guaranteed; however, if the condition is violated, no conclusion can be made.

  • PDF

Stability of the Robot Compliant Motion Control, Part 2 : Implementation (로보트의 Compliance 제어에서의 안정성:구현)

  • Kim, Sung-Kwun
    • The Transactions of the Korean Institute of Electrical Engineers
    • /
    • v.38 no.11
    • /
    • pp.950-957
    • /
    • 1989
  • We have shown how unstructured modeling was used to derive a general stability condition in Part 1. In Part 2, we focus on the particular dynamics (structured modiling) of the robot manipulator and environment. Using rigid body dynamics, the stability condition for the direct drive robots has been achieved in terms of the Jacobian and robot tracking controller. Combining the structured and unstructured modeling, a stability condition for a particular application can be obtained. This approach has been used to analyze compliant motion on the University of Minnesota robot using a feedforward torque controller. We have obtained a stability condition for this application. Through both simulation and experiment, the sufficiency of this condition has been demonstrated. For a sufficient stability condition, recall that if the condition is satified, then the stability is guaranteed` however, if the condition is violated, no conclusion can be made.

  • PDF

Study on Classification of Pulse Condition of the Chronological Medical Practitioners (역대의가(歷代醫家)의 맥상(脈象) 분석(分類)에 대한 연구)

  • Park, Jae-Won;Kim, Byung-Soo;Kang, Jung-Soo
    • Journal of Physiology & Pathology in Korean Medicine
    • /
    • v.22 no.6
    • /
    • pp.1347-1353
    • /
    • 2008
  • Pulse condition is the essential division for conducting pulse diagnosis which is one of the most fundamental and important diagnostics in traditional Korean/Chinese medicine. We studied the pulse condition referred to classics of traditional medicine for a full understanding in present time and come to a conclusion like below. The reference to pulse condition was concluded to 'twenty four pulse conditions' which is the fundamental conception generally accepted in present age since it had first mentioned in "Huangdi Neijing" and after it had passed through "Nanjing", "pulse pattern identification-chapter of normal pulse"of Zhang Zhongjing and reached "Maijing"of Wang Shuhe. Although medical partitioners had different views to some extent about pulse condition, there were no significant differences in the main theoretical frame. Even though there had been a diversity of opinions on the classification of pulse-condition between various medical practitioners, the method of Dae-dae and the method of systematic endeavored by Zhou Xueting and Zhou Xuehai who were medical scholars in the Ch'ing dynasty have been a criterion for the classification of pulse-condition up to date. We were able to recognize that the change of pulse condition caused by pathological situation should be compared to physiological pulse condition for detecting the deficiency and excess by researching the analyzing methods of pulse condition mentioned in the "Lingshu", and the book of Hua Shou and Zhou Xuehai). To sum up, first normal pulse which is the physiological pulse condition should be a standard for detecting physiological pulse condition. Secondly, Zhou Xueting insisted that relaxed pulse should be a standard pulse condition for detecting normal pulse.