• Title/Summary/Keyword: Units

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A Study on Correct Usage of SI Units and School Education for Units (SI 단위계 사용의 정확성과 단위교육의 필요성에 관한 연구)

  • Kim Seong-Gon;Song Chul-Ki
    • Journal of Engineering Education Research
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    • v.7 no.2
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    • pp.51-59
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    • 2004
  • The signs have been used as the world-wide common language. Because all units have their own meanings, their usage should be kept correctly. This paper shows how middle school students know and keep the usage of SI units. And this paper shows the necessity of teaching the students correct units in their schools.

A Study on Historical and Cultural Viewpoints of Traditional Measuring Units Conversion (전통적인 길이 척도 환산에 대한 역사·문화적 재고)

  • Lee, DongMyung;Kim, JaeHyo;Kang, YeonSeok;Ko, HoKyoung
    • The Journal of Korean Medical History
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    • v.23 no.2
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    • pp.15-22
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    • 2010
  • Currently, in Korea, all lengths are written in "meter" unit, and the non-statutory measuring units are banned for use. However, in some fields, traditional measuring units are widely used with necessary modifications, and people in such fields raise varying arguments on conversion to "meter" unit. This research examines traditional measuring units from historical and cultural viewpoints, and provides suggestions on how to improve consistency and standardization for more accurate and effective exchangeof scientific opinions.

Evaluation of Partial Safety Factors of Armor Units by Inverse-Reliability Analysis (역해석법에 의한 피복재의 부분안전계수 산정)

  • Lee, Cheol-Eung;Park, Dong-Heon
    • Journal of Industrial Technology
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    • v.28 no.B
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    • pp.149-156
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    • 2008
  • A reliability model of Level II AFDA is developed to analyze the stability of armor units on the sloped coastal structures. Additionally, the partial safety factors of random variables related to armor units can be straightforwardly evaluated by applying the inverse-reliability method in which influence coefficients and uncertainties of random variables, and target probability of failure are combined directly. In particular, a design equation for armor units is derived in terms of the same criteria as deterministic design method in order to apply the reliability-based design method of Level I without some understanding to the reliability analysis. Finally, it is confirmed that several results redesigned by the reliability-based design method of Level I have satisfactorily agreement with results of CEM as well as those of Level II AFDA.

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Goal Regulation Mechanism through Reinforcement Learning in a Fractal Manufacturing System (FrMS) (프랙탈 생산시스템에서의 강화학습을 통한 골 보정 방법)

  • Sin Mun-Su;Jeong Mu-Yeong
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2006.05a
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    • pp.1235-1239
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    • 2006
  • Fractal manufacturing system (FrMS) distinguishes itself from other manufacturing systems by the fact that there is a fractal repeated at every scale. A fractal is a volatile organization which consists of goal-oriented agents referred to as AIR-units (autonomous and intelligent resource units). AIR-units unrestrictedly reconfigure fractals in accordance with their own goals. Their goals can be dynamically changed along with the environmental status. Since goals of AIR-units are represented as fuzzy models, an AIR-unit itself is a fuzzy logic controller. This paper presents a goal regulation mechanism in the FrMS. In particular, a reinforcement learning method is adopted as a regulating mechanism of the fuzzy goal model, which uses only weak reinforcement signal. Goal regulation is achieved by building a feedforward neural network to estimate compatibility level of current goals, which can then adaptively improve compatibility by using the gradient descent method. Goal-oriented features of AIR-units are also presented.

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A Study on the Development of Thermal Storage Units for Efficient Utilization of Solar Systems (태양열 시스템의 활용성 제고를 위한 축열 장치 개발에 관한 실험적 연구)

  • Chun, Won-Gee;Lee, Jae-Young
    • Journal of the Korean Solar Energy Society
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    • v.22 no.1
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    • pp.31-42
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    • 2002
  • This study has been carried out to design a number of storage units which could improve the utilizability of solar energy by offering convenient means to store it. The proposed units are systematically tested to establish their reliability in actual operations. One of the prominent features of the present storage units is that each design is meant to drastically improve the thermal response of solar systems which would definitely offer extreme convenience to whoever uses it. Also sought in the present study is to elicit ideal operating conditions during the storage and extraction phases of solar energy once it is delivered to the storage unit. The present study has confirmed the potential use of the proposed units with their applicability in capitalizing the sun's energy.

Effects of the Power Transmission Units on the Rotational Accuracy of A Hydrostatic Spindle (동력전달요소에 따른 유정압 주축의 회전정밀도에 관한 연구)

  • Park, C.H.;Ryu, G.W.;Jung, Y.G.
    • Journal of the Korean Society for Precision Engineering
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    • v.12 no.2
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    • pp.59-68
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    • 1995
  • In this study, the effects of the power transmission units on the rotational accuracy are investigated experimentally in a hydrostatic spindle. The effects of warm up time, unbalancing and the position of measuring sensor are pre-examined for the determination of measuring conditions. The misalignment of the power transmission units and the vibration excited by the fluctuation of belt are considered as the dominant parameters of error motion. The variation and scatter of run out at the range of 0 to 3,000rpm in rotational speed are appropriated for the camparison of availabilities of the transmission units to precision spin- dles.

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Performance of Pseudomorpheme-Based Speech Recognition Units Obtained by Unsupervised Segmentation and Merging (비교사 분할 및 병합으로 구한 의사형태소 음성인식 단위의 성능)

  • Bang, Jeong-Uk;Kwon, Oh-Wook
    • Phonetics and Speech Sciences
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    • v.6 no.3
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    • pp.155-164
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    • 2014
  • This paper proposes a new method to determine the recognition units for large vocabulary continuous speech recognition (LVCSR) in Korean by applying unsupervised segmentation and merging. In the proposed method, a text sentence is segmented into morphemes and position information is added to morphemes. Then submorpheme units are obtained by splitting the morpheme units through the maximization of posterior probability terms. The posterior probability terms are computed from the morpheme frequency distribution, the morpheme length distribution, and the morpheme frequency-of-frequency distribution. Finally, the recognition units are obtained by sequentially merging the submorpheme pair with the highest frequency. Computer experiments are conducted using a Korean LVCSR with a 100k word vocabulary and a trigram language model obtained by a 300 million eojeol (word phrase) corpus. The proposed method is shown to reduce the out-of-vocabulary rate to 1.8% and reduce the syllable error rate relatively by 14.0%.

A Study on the Units of Measuring Scale in Hwangnyongsa Temple Planning (황룡사 가람계획 척도 연구)

  • Kim, Sookyung
    • Journal of architectural history
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    • v.25 no.4
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    • pp.65-73
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    • 2016
  • This paper aimed to identify the units of measuring scale in Hwangnyongsa temple planning with the published excavation survey reports. Hwangyongsa temple site was planned under Silla Capital's urban planning in 6~7C, its full size was $800{\times}800$, and main temple was $400{\times}515$ of Goguryeo's system of measurement. Main hall was located in the center of Hwangnyongsa temple site, and its location could be seen that there was the arrangement of main temple divided into 3 : 2. Building plan measuring units proved to be 351~356mm and 294~ 296mm by analyzing measured data of remains. Lecture hall and Wooden pagoda were rebuilt by using the ancestors' units of measuring scale again and Bell hall was not planned by Tang's system of measurement in middle of 8C. In this respect, it would be important to have a deliberate attitude and lay down stereotypes on research of the units of measuring scale in ancient architecture.

Characteristics of polymerization in nanofiller-containing composite resins (나노필러를 포함하고 있는 복합레진의 중합특성)

  • Lee, Hee-Kyung
    • Journal of Technologic Dentistry
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    • v.29 no.2
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    • pp.9-15
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    • 2007
  • As the development of nanotechnology, the use of composite resins which containing nanofillers becomes popular. The purpose of this study was to test the degree of polymerization of nanofillercontaining composite resins. For the study, three different nanofiller-containing composite resins and two different light-curing units were used. To evaluate the degree of polymerization, the maximum polymerization shrinkage taking place during the light curing, and the microhardness, after the light curing, were measured. As results, two light-curing units exhibited a similar emission spectrum to that of the included photoinitiator, camphorquinone. The only difference between the light-curing units were the width of the emission spectrum. Three different composite resins showed different microhardness values. Among them, Grandio showed the greatest microhardness value. However, there was less microhardness difference on the top and bottom surfaces due to the difference of the light-curing units. The maximum polymerization shrinkage values were also similar in the tested specimens regardless of the difference of the light-curing units. However, Grandio showed the least polymerization shrinkage. According to the manufacturers' data, Grandio showed the highest filler content(vol%).

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Airfleet의 임무효과

  • Kim Yeong-Hwi;Ha Seok-Tae
    • Journal of the military operations research society of Korea
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    • v.15 no.1
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    • pp.14-27
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    • 1989
  • This paper deals with the mission effectiveness of an airfleet, Airfleet operating system consists of a finite number of units performing the several mission types. Earlier works for the mission effectiveness of a fleet is limited to only one mission type and computer simulation approaches. The mission effectiveness. model of a fleet is constructed by three attributes - the mission readiness of the units, the mission reliability and capability of units. The environmental conditions and human factors affecting the mission success are considered together. The solution of the model is obtained by analytical technique. Especially, AOS is considered a closed queueing network with a finite number of units and a single job class. And then, the mission readiness of the units is found by the mean value analysis. The model would be a useful tool to readily evaluate mission effectiveness of a airfleet as it is and provide a criterion for determining the optimal operating policy.

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