• Title/Summary/Keyword: 절대 안정

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Empirical Study of the Long-Term Memory Effect of the KOSPI200 Earning rate volatility (KOSPI200 수익률 변동성의 장기기억과정탐색)

  • Choi, Sang-Kyu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.12
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    • pp.7018-7024
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    • 2014
  • This study examined the squared returns and absolute returns of KOSPI 200 with GPH (Geweke and Porter-Hudak, 1983) estimators. GPH was estimated by the long-term memory preserving time series parameter d in linear regression. This called the GPH estimator, which depends on a bandwidth m. m was decided by confirming the stable section of the point estimate by validating the track of the GPH estimator according to the value of m. The result suggests that by satisfying 0< d <0.5, the squared returns and absolute returns of KOPI 200 retains long-term memory.

Variable Step Size Adaptive Algorithm using Instantaneous Absolute Value Based on System Generator (시스템 제너레이터 환경에서 순시 절대값을 이용한 가변스텝사이즈 적응알고리즘)

  • Lee, Chae-Wook;Ryu, Jeong-Tak
    • Journal of Korea Society of Industrial Information Systems
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    • v.21 no.3
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    • pp.1-6
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    • 2016
  • As the convergence speed of time domain adaptive algorithm on the LMS(Least Mean Square) becomes slow when eigen value distribution width is spread, So variable step size algorithm is used widely. But it needs a lot of calculation load. In this paper we consider new algorithm, which can reduce calculations and improve convergence speed, uses instantaneous absolute value of average noise signal adapting the exponential function. For the performance of proposed algorithm is tested and simulated to system generator. As the result we show the variable step size adaptive algorithm in proportion to instantaneous absolute value is more stable and efficient than others.

Case Studies for the Stress Measurements on the Shotcrete Tunnel Lining (터널에서의 숏크리트 응력 측정 사례 연구)

  • Kim, Hak Joon;Kim, Mi-Ran
    • The Journal of Engineering Geology
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    • v.24 no.1
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    • pp.81-89
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    • 2014
  • Stress measurements of shotcrete lining were performed to evaluate the stability of the primary lining and to determine the thickness and the construction timing of the secondary lining. The current situation of stress measurements of shotcrete and problems related to judging the safety of shotcrete linings are presented, based on the results of several case studies. An improved method of performing stress measurements on shotcrete lining is also presented. In evaluating the safety of shotcrete lining, the use of absolute values of measured stresses would improve the reliability of the measurements.

The study for grading of the mudflat by birds (조류에 의한 갯벌의 등급화 연구)

  • Lee, Ki Sup;Kim, Mi Ran;Lee, Si Wan;Lee, Han Soo
    • Journal of Wetlands Research
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    • v.6 no.1
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    • pp.105-115
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    • 2004
  • This study was carried out to grade and evaluate the intertidal mudflat by birds. The mudflat was graded by two methods such as the scoring and ranking. First, for the scoring of the mudflat, five factors were estimated; population size, the number of protected species, the individuals of protected birds, the number of species(or subspecies) over 1% level of the survival population, and 1% level of the domestic population. After scoring of these five factors, the grade was scored by total. Second, for the ranking, six factors were estimated; population size, the density of birds, the index of species diversity, species richness, species evenness, and population stability. After ranking of these six factors, the grade was relatively ranked. Five grade by scoring was the important mudflat for the value of international preservation, and the most mudflats of the estuary gained V grade. The higher grades by ranking were the mudflats of Nakdonggang and Mankyunggang river estuaries. And the inner mudflats were more valuable than the outer mudflats in Mankyunggang & Dongjingang river estuaries. The grading of the mudflat by birds can be used for estimating and appointing of the important mudflats, and suggested the objective of criteria for the effective preservation and management.

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Total Management System for Earth Retaining Structures Using Observational Method (지반굴착 흙막이공의 정보화시공 종합관리 시스템)

  • 오정환;조철현;김기웅;백영식
    • Journal of the Korean Geotechnical Society
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    • v.18 no.2
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    • pp.51-64
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    • 2002
  • Observational results of ground movement during the construction were very different from those predicted during the analysis of design step because of the uncertainty of the numerical analysis modelling, the soil parameter, and the condition of a construction field, etc., however accurately numerical analysis method was applied for prediction of ground movement per the excavation step. Therefore, the management system through the construction field measurement should be achieved for grasping the situation during the excavation. Until now, the measurement system restricted by 'Absolute Value Management system'analyzing only the stability of present step has been executed. So, it was difficult to expect the prediction of ground movement fur the next excavation step. In this situation, this study developed 'The Management system TOMAS-EXCAV'consisted of 'Absolute value management system'analyzing the stability of present step and 'Prediction management system'expecting the ground movement of next excavation step and analyzing the stability of next excavation step by 'Back Analysis'. TOMAS-EXCAV could be applied to all the uncertainty of earth retaining structures analysis by connecting 'Forward analysis program'and 'Back analysis program'and optimizing the main design variables using SQP-MMFD optimization method through measurement results. The applicability of TOMAS-EXCAV was confirmed by back analysis selecting two earth retains construction fields.

Isolation and Characterization of Cyclodextrin Glycosyl Transferase Producing Alkalophilic Bacillus sp. (Cyclodextrin glycosyltransferase를 생산하는 호알칼리성 Bacillus속 미생물)

  • 유주현;정용준;이정수
    • Microbiology and Biotechnology Letters
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    • v.17 no.2
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    • pp.148-153
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    • 1989
  • A strain of alkalophilic Bacillus sp. YC-335 has been isolated from soil. The strain was capable of producing large amount of cyclodextrin glycosyl transferase (CGTase) in the culture broth. The preferable medium composition has been determined to be as follows : 1.5% soluble starch, 5% corn steep liquor, 0.1% $K_2$HPO$_4$, 0.02%mgSO$_4$.7$H_2O$, 1% CaCO$_3$and 1% Na$_2$CO$_3$(pH 10.3). The highest enzyme production was observed after 48 hours of cultivation at 31$^{\circ}C$. The optimum pH and temperature for the activity of crude enzyme were 6.0 and 5$0^{\circ}C$, respectively. The enzyme was stable between pH 5 and 9, and upto 5$0^{\circ}C$. The enzyme converted starch into $\alpha$-, $\beta$- and ${\gamma}$-CD in the relative amounts of 1:10:1.5, respectively.

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Influence of Weak Ground Ahead of the Tunnel Face on 3D-displacement and Face Extrusion (막장전방의 연약층이 터널 3차원변위 및 막장 수평변위에 미치는 영향)

  • Jeon, Je-Sung
    • Journal of the Korean Geotechnical Society
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    • v.19 no.6
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    • pp.189-206
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    • 2003
  • During tunnel excavation in urban area a systematic monitoring is important for the purpose of determination of support type and quantity, as well as for the control of stability of both surface structures and the tunnel itself due to the frequently, and in many cases, abruptly changing ground condition. In Austria absolute displacement monitoring methods have replaced relative displacement measurements by geodetic methods to a large extent. Prompt detection of weak ground ahead of the tunnel face as well as better adjustment of excavation and support to the geotechnical conditions is possible with the help of the improved methods of data evaluation on sites. Deformation response of the ground to excavation starts ahead of the tunnel face, therefore, the deformation and state of the tunnel advance core is the key factor of the whole deformation process after excavation. In other words, the rigidity and state of the advance core play a determining role in the stability of both surface structures and the tunnel itself. This paper presents the results from detailed three-dimensional numerical studies, exploring vertical displacements, vector orientations and extrusions on tunnel face during the progressive advancement for the shallow tunnel in various geotechnical conditions.

Comparison of Morphological Characters and Stable Isotopes of Seeds between Wild Simulated Ginseng and Cultivated Field Ginseng (국내 산양삼과 인삼 종자의 형태적 형질과 안정성 동위원소 비교)

  • Choi, Myoung Sub;Kim, Sunhee;Park, Chan Ryul;Kim, Namyoung;Shin, Jinsub
    • Journal of Korean Society of Forest Science
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    • v.97 no.4
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    • pp.357-362
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    • 2008
  • We compared the morphological characters and stable isotopes of seeds of wild simulated ginseng with those of cultivated field ginseng. Seeds were collected from ten areas for wild simulated ginseng and two areas for cultivated field ginseng. The length, width, thickness and number of seeds per gram were measured and the ratio of stable isotopes of carbon and nitrogen was analysed as well. There was a overlapping variation of morphological characters and the ratio of stable isotope of the wild simulated ginseng among study areas. In Geumsan area, compared with the seed of cultivated field ginseng, the seed of wild simulated ginseng was significantly small and light, and the ${\delta}^{15}N$(‰) of wild simulated ginseng was lower than that of cultivated field ginseng. However, it is somewhat impossible to compare the regional variation of the unique value of ${\delta}^{15}N$(‰) among study areas of wild simulated ginseng. We can suggest the value of ${\delta}^{15}N$(‰) can be used as detection factor for cultivation regime like chemical fertilization and organic farming.

Changes of bite force and occlusal contacts after stabilization splint therapy (교합안정장치 사용후 교합력 및 교합접촉의 변화양상에 관한 연구)

  • Park, Hyung-Soo;Kim, Kwang-Won;Yoon, Young-Jooh
    • The korean journal of orthodontics
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    • v.30 no.1 s.78
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    • pp.91-99
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    • 2000
  • This study was done to identify the changes of bite force and occlusal contact between before and after stabilization splint therapy. 16 female patients, accepted for orthodontic treatment at the Department of Orthodontics, College of Dentistry, Chosun University, were selected as the sample of this investigation. For comparisons, the samples of 16 were divided into just before stabilization splint, 1 month after stabilization splint, 2 months after stabilization splint, and 3 months after stabilization splint and used the T-scan system to identify the bite force and occlusal contact changes for each group. Statistical analysis of the data was carried out ANOVA tests, and Turkey tests using $SPSS/PC^+$. The results were as follows : 1. Bite force change from just before treatment to 1 month after stabilization splint therapy was statistical significantly decreased (P<0.05). 2. Bite force changes from 1 to 3 months after stabilization splint therapy showed no statistical significance (p>0.05). 3. The changes of anterior occlusal contacts showed no statistical significance regardless of the wearing periods of stabilization splint (P>0.05). 4. The changes of posterior occlusal contacts from just before treatment to 1 month after stabilization splint therapy was statistical significantly decreased (P<0.05). 5. The changes of posterior occlusal contacts Outing 1 to 3 months after stabilization splint therapy showed no statistical significance (P>0.05). 6. Posterior teeth rather than anterior teeth were more influenced by the changes of the number of occlusal contacts. To sum up above results, we may respect to capturing and stabilizing centric relation Position just 1 month after stabilization splint therapy.

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Effect of Bed Side Exercising on Back Pain and Bleeding Complications after Transcatheter Arterial Chemoembolization (간동맥 화학색전술 후 절대안정기간 동안의 침상운동요법이 요통과 출혈합병증에 미치는 효과)

  • Nam, Sun Hee;Kim, Young-Ju
    • Korean Journal of Adult Nursing
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    • v.25 no.4
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    • pp.400-408
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    • 2013
  • Purpose: This study was conducted to examine the effects of bed side exercising on back pain and bleeding during absolute bed rest in patients who had received transcatheter arterial chemoembolization (TACE). Methods: A nonequivalent control group pretest-posttest design was used. A total 46 patients were sampled from a gastrointestinal unit of a urban general hospital in Seoul. The control group received 8 hours of bed rest and conservative care. The experimental group received 8 hours of bed rest and bed side exercising every one hour from the time having absolute bed rest for 3 hours after TACE. Results: The experimental group with bed side exercising experienced significantly less back pain compared to the control group. There was no significant difference in the incidence of bleeding complications between two groups. Conclusion: The results indicate that a bed side exercising is associated with a reduction of back pain and with no increased risk of bleeding complications in patients after TACE.