• Title/Summary/Keyword: Level Set method

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OD matrix estimation using link use proportion sample data as additional information (표본링크이용비를 추가정보로 이용한 OD 행렬 추정)

  • 백승걸;김현명;신동호
    • Journal of Korean Society of Transportation
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    • v.20 no.4
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    • pp.83-93
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    • 2002
  • To improve the performance of estimation, the research that uses additional information addition to traffic count and target OD with additional survey cost have been studied. The purpose of this paper is to improve the performance of OD estimation by reducing the feasible solutions with cost-efficiently additional information addition to traffic counts and target OD. For this purpose, we Propose the OD estimation method with sample link use proportion as additional information. That is, we obtain the relationship between OD trip and link flow from sample link use proportion that is high reliable information with roadside survey, not from the traffic assignment of target OD. Therefore, this paper proposes OD estimation algorithm in which the conservation of link flow rule under the path-based non-equilibrium traffic assignment concept. Numerical result with test network shows that it is possible to improve the performance of OD estimation where the precision of additional data is low, since sample link use Proportion represented the information showing the relationship between OD trip and link flow. And this method shows the robust performance of estimation where traffic count or OD trip be changed, since this method did not largely affected by the error of target OD and the one of traffic count. In addition to, we also propose that we must set the level of data precision by considering the level of other information precision, because "precision problem between information" is generated when we use additional information like sample link use proportion etc. And we Propose that the method using traffic count as basic information must obtain the link flow to certain level in order to high the applicability of additional information. Finally, we propose that additional information on link have a optimal counting location problem. Expecially by Precision of information side it is possible that optimal survey location problem of sample link use proportion have a much impact on the performance of OD estimation rather than optimal counting location problem of link flow.

Analysis of the Value Relevance on International Financial Reporting Standards Fair Value in China (중국의 국제기업회계기준 공정가치의 가치 관련성 분석)

  • Kim, Dong-Il
    • Journal of Digital Convergence
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    • v.12 no.9
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    • pp.75-81
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    • 2014
  • This study is analyzed using the Shanghai stock market and Shenzhen stock market data in order to analyze the usefulness of accounting information to appear from the introduction of international accounting standards in China. Summarized the relevant previous researches for objective study approach, studied the hypothesis based on the empirical analysis and set a hypothesis as adjusting the stuffs to fix in this research model. In this study, Analyzed the hypothesis to input of detailed variables for analyzing the value relevance between periods before fair value and after fair value. Also, in this hypothesis study, analyzed and estimated to affect the quality of information the acceptant period when compare with acceptant periods and before periods of fair value. These results suggested that impact the net asset value per share and earnings per share of the company because the value of the relationship had statistically significant at the level of relevance. Therefore, in the future studies about fair value assessment, will be expected that usefulness of the enterprise value evaluation method enable to discuss it such as critical sucess factors.

Effects of Fatigue Induction on Ground Reaction Force Components, Postural Stability, and Vertical Jump Performance in Taekwondo Athletes

  • Hyun, Seung-Hyun;Kim, Young-Pyo;Ryew, Che-Cheong
    • Korean Journal of Applied Biomechanics
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    • v.26 no.2
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    • pp.143-151
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    • 2016
  • Objective: The purpose of this study was to investigate the effect of fatigue induction on ground reaction force (GRF) components, postural stability, and vertical jump performance in Taekwondo athletes. Method: Ten Taekwondo athletes (5 men, 5 women; mean age, $22.30{\pm}2.62years$; mean height, $174.21{\pm}9.20cm$; mean body weight, $67.28{\pm}12.56kg$) participated in this study. Fatigue was induced by a short period of strenuous exercise performed on a motorized treadmill. The analyzed variables included vertical jump performance, static stability (mediolateral [ML], center of pressure [COP], anteroposterior [AP] COP, ${\Delta}COPx$, ${\Delta}COPy$, and COP area), postural stability index values (ML stability index [MLSI], AP stability index [APSI], vertical stability index [VSI], dynamic postural stability index [DPSI]), and GRF components (ML force, AP force, peak vertical force [PVF], and loading rate). To analyze the variables measured in this study, PASW version 22.0 was used to calculate the mean and standard deviation, while a paired t-test was used to evaluate the pre- versus post-fatigue results. Pearson's correlation coefficients among variables were also analyzed. The statistical significance level was set at ${\alpha}$ = .05. Results: Vertical jump performance decreased significantly after the induction of fatigue, while AP COP, ${\Delta}COPx$, COP area, APSI, VSI, and DPSI increased significantly. PVF and loading rate increased significantly after the induction of fatigue, while the postural stability variables (AP COP, ${\Delta}COPy$, COP area, APSI, VSI, DPSI) were similarly correlated with GRF components (PVF, loading rate) after fatigue was achieved (r = .600, $R^2$ = 37%). Conclusion: These results suggest that the induction of fatigue can decrease postural stability and exercise performance of Taekwondo athletes during training and competition sessions.

Effects of Joint Mobilization on Foot Pressure, Ankle Moment, and Vertical Ground Reaction Force in Subjects with Ankle Instability

  • Yoon, Na Mi;Seo, Yeon Soon;Kang, Yang-Hoon
    • Korean Journal of Applied Biomechanics
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    • v.26 no.2
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    • pp.153-159
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    • 2016
  • Objective: The purpose of this study was to investigate the effects of joint mobilization on foot pressure, ankle moment, and vertical ground reaction force in subjects with ankle instability. Method: Twenty male subjects (age, $25.38{\pm}3.62yr$; height, $170.92{\pm}5.41cm$; weight, $60.74{\pm}9.63kg$; body mass index (BMI), $19.20{\pm}1.67kg/m^2$) participated and underwent ankle joint mobilization. Weight-bearing distribution, ankle dorsi/plantar flexion moment, and vertical ground reaction force were measured using a GPS 400 and a VICON Motion System (Oxford, UK), and subsequently analyzed. SPSS 20.0 for Windows was used for data processing and paired t-tests were used to compare pre- and post-mobilization measurements. The significance level was set at ${\alpha}$ = .05. Results: The results indicated changes in weight-bearing, ankle dorsi/plantar flexion moment, and vertical ground reaction force. The findings showed changes in weight-bearing distribution on the left (pre $29.51{\pm}6.31kg$, post $29.57{\pm}5.02kg$) and right foot (pre $32.40{\pm}6.30kg$, post $31.18{\pm}5.47kg$). There were significant differences in dorsi/plantar flexion moment (p < .01), and there were significant increases in vertical ground reaction forces at initial stance (Fz1) and terminal stance (Fz2, p < .05). Additionally, there was a significant reduction in vertical ground reaction force at midstance (Fz2, p < .001). Conclusion: Joint mobilization appears to alter weight-bearing distribution in subjects with ankle instability, with resultant improvements in stability.

Fisheries resources management of crucian carp based on assessment of fish stock and potential yield in the mid-upper system of Seomjin River

  • Ryu, Hui Seong;Jang, Sung Hyun;Lee, Jung Ho;Lee, Jung Joon
    • Journal of Ecology and Environment
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    • v.37 no.4
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    • pp.209-216
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    • 2014
  • This study was undertaken to suggest an effective fisheries resources management system by using stock assessment and potential yield analyses of crucian carp population in the mid-upper system of the Seomjin River. Fieldwork was conducted seasonally from 2008 to 2009 in the mid-upper system of the Seomjin River. The stock assessment was carried out by the swept area method and the potential yield was estimated by improved fisheries resource potential estimation system based on the Allowable Biological Catch. Also, the yield-per-recruit analysis was used to review the efficient management implication of the resource, Carassius auratus. As a result, the age at first capture ($t_c$) was estimated as 1.468 year, converted body length (BL) was 10.8 cm. Meaning the current fishing intensities, the instantaneous coefficient of fishing mortality (F) was $0.067year^{-1}$, and the yield-per-recruit analysis showed that the current yield per recruit was estimated to be 15.999 g with F and $t_c$. The instantaneous rate of fishing mortality that provides for Allowable Biological Catch ($F_{ABC}$) based on the current $t_c$ and F was estimated as $0.618year^{-1}$. Therefore, the optimum fishing intensities could be achieved at the higher fishing intensity for Carassius auratus. The calculated annual stock of C. auratus was estimated as 7,608 kg, and the potential yield was estimated as 343 kg with $t_c$ and F at the fixed current level. Using yield-per-recruit analysis, if F and $t_c$ were set at $0.618year^{-1}$ and 2 year, the yield per recruit and total allowable catch would be predicted to increase to 62 g and 2,531 kg by about 3.9 times and 7.3 times, respectively.

The Effects of Fowler's Position Change on Back Pain and Discomfort of the Patients Following Percutaneous Coronary Intervention (경피적 관상동맥중재술 후 반좌위 체위변경이 환자의 요통과 불편감에 미치는 효과)

  • Nam, So-Young;ChoiKwon, Smi
    • Perspectives in Nursing Science
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    • v.7 no.1
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    • pp.55-64
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    • 2010
  • Purpose: The purpose of this study was to examine the effects of position change from supine to Fowler's on back pain and discomfort in patients who remained on bed rest after undergoing PCIs with a vascular closure device. Methods: Data was collected from 35 inpatients who were hospitalized in coronary-care unit to perform PCIs with a vascular closure device at S hospital in Seoul from December, 2006 to May, 2007. Back pain, discomfort, presence and grade of bleeding and hematoma from femoral arterial puncture site and blood pressure/pulse rate were measured prior to, 10 minutes, 1 hour and 2 hours after position change. Data was analyzed with descriptive statistics, $x^2$ tests and t-tests using SPSS/WIN 12.0 for Windows program. The level of significance (${\alpha}$) was set at 0.05 for this study. Results: We found that there was no significant difference in back pain and discomfort in 10 minutes after position change between the two groups. However, the experimental group reported significantly less back pain and discomfort than the control group in 1 hour (p<.01, respectively) and 2 hour (p<.01, respectively) after position change. There was no significant difference in the presence and grade of bleeding and hematoma at the puncture site, blood pressure, and pulse rate in 10 minutes, 1hour and 2hours after position change between the two groups. Conclusion: Fowler's position change after PCIs in, therefore, safe and effective method of reducing back pain and physical discomfort without causing additional bleeding and changes in blood pressure and pulse rate.

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The Comparative Study of the First Ladies' Fashion Style from a Perspective of Modernism and Postmodernism - Centering around Jacqueline Kennedy and Michelle Obama - (모더니즘과 포스트모더니즘 관점에서 본 퍼스트레이디 패션 스타일 비교연구 - 재클린 케네디와 미셸 오바마를 중심으로 -)

  • Lee, Misuk
    • Journal of the Korean Society of Costume
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    • v.63 no.8
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    • pp.14-26
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    • 2013
  • The purpose of this study is to compare and analyze Jacqueline Kennedy and Michelle Obama's fashion style from a perspective of modernism and postmodernism. The method utilized in this study was first, to examine the properties of modernism and postmodernism. Next, we explored the types of role performance of the first ladies and the application of their fashion as an aid to their roles through the precedents of the research concerning modernism and postmodernism. The results of the study are as follows. First, there was a trend of formalism and anti-formalism. Jacqueline Kennedy made her public appearances wearing a formal dress in order to express the first lady's authoritarian figure of restrained elegance. The fashion of the first lady aspired to formalism. Meanwhile, Michelle Obama followed more of a free style by eschewing the typical formality of the first lady. She created diverse styles utilizing a variety of items, which were not interrupted by form or by using heterogeneous items. Second, there is a trend of elitism and populism. While Jacqueline Kennedy preferred only haute couture designers' costume in order to show the prestige and dignity of the upper class, Michelle Obama patronized unknown designers' clothing or mid-level casual brand goods that the public favors in order to interact with the public through her fashion. Third, while modernism regards totality or unity to be important, postmodernism puts an emphasis on the eclecticism by pursuing complexity and diversity through the deconstruction of an indigenous genre. In case of Jacqueline Kennedy, this tendency featured monotone clothing color, which presented a unified full set dress that excluded decoration. Michelle Obama, in contrast, mixed and matched formal dresses and a casual cardigan or felicitously mixed luxury brand or low to middle priced brand goods.

Distributions of Hydrogeological Variables and Flow Field on GIS Digital Map (GIS 수치지도를 이용한 수리지질학적 변수와 지하수 유동의 분포)

  • Lee, Cheo K.
    • Journal of the Korean Association of Geographic Information Studies
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    • v.2 no.2
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    • pp.45-58
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    • 1999
  • Digital map is utilized for an effective display of the distributions of the hydrogeological variables such as water table height(hydraulic head) and log-transmissivity(lnT) in north Pohang, KyungBug. Specifically the geostatistical method kriging is used to construct the distributions in an unconfined aquifer from a finite set of measured data. The experimental variograms for both the head and lnT suggest spherical models with nugget of 0 and range of 6km. The kriged results by using these variograms show that the head decreases primarily from the west to the east with a large peak in the north-western part and lnT is at the maximum level in the central part with outwardly decreasing trend. The constructed delineation is also used to calculate the flow field in the region. Finite differences with second order consistency are used to calculate the fluxes in the east(x) and north(y) across a vertical cross-section of unit width and height equal to the thickness of the wet zone in the aquifer. It is demonstrated that the flow is dominantly in the east with diverging trend on the eastern hillside of the water table peak. A few convergent spots also appear.

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Estimation of Pollution Contribution TMDL Unit Watershed in Han-River according to hydrological characteristic using Flow Duration Curve (유량지속곡선을 이용한 수문특성별 한강수계 총량관리 단위유역의 오염기여도 추정)

  • Kim, Dong Young;Yoon, Chun Gyeong;Rhee, Han Pil;Choi, Jae Ho;Hwang, Ha Sun
    • Journal of Korean Society on Water Environment
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    • v.35 no.6
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    • pp.497-509
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    • 2019
  • After the Total Maximum Daily Loads(TMDLs) was applied, it became beyond the limit of concentration management. However, it does not adequately reflect the characteristics of various watersheds, and causes problems with local governments because of the standard flow set. Thus, in this study, the Han River system is organized into four groups in estimating the Pollution Contribution by applying the Flow Duration Curve(FDC) created by the daily flow of data from the HSPF. And the method of this study is expected to be valuable as basic data for the TMDLs. As a result, Group I contains the main watersheds with no large hydraulic structures and tributary watersheds. There is no specificity in the FDC and the Pollution Contribution is estimated as rainfall runoff. Group II contains watersheds near the city where the FDC is maintained above a certain level during the Low Flow Conditions and the Pollution Contribution is estimated as the discharge flow of large scale point pollution facilities. Group III contains the main watersheds in which the large hydraulic structures are installed and FDC is curved in the Low Flow Conditions. So the Pollution Contribution is estimated as the water quality of the large hydraulic structures. Group IV contains the upstream in mainstream watersheds in which the large hydraulic structures are installed and the FDC is disabled before the Low Flow Conditions. As the flow is concentrated in the High Flow Conditions, the non-point pollution sources are estimated as the Pollution Contribution.

Determination of In-focus Criteria In Image Processing Method for Particle Size Measurement (입경측정을 위한 영상처리기법에서 입자 초점면 존재 판단 기준의 설정)

  • Koh, Kwang Uoong;Kim, Joo Youn;Lee, Sang Yong
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.23 no.3
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    • pp.398-407
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    • 1999
  • In the present image processing technique, the concept of the gradient indicator(GI) has been introduced to find out the depth-of-field in sizing large particles ranging from $30{\mu}m$ to $30{\mu}m$ where using of the concept of the normalized contrast value(VC) is not appropriate. The gradient indicator is defined as the ratio of the local value to the maximum possible value of the gray-level gradient in an image frame. The gradient indicator decreases with the increases of the particle size and the distance from the exact focal plane. A particle is considered to be in focus when the value of the gradient indicator at its image boundary stays above a critical value. This critical gradient indicator($GI_{critical}$) is defined as the maximum gradient indicator($GI_{max}$) subtracted by a constant ${\Delta}GI$ which is to account for the particle-size effect. In the present ca.so, the value of ${\Delta}GI$ was set to 0.28 to keep the standard deviation of the measured particles mostly within 0.1. It was also confirmed that, to find the depth-of-field for small particles(${\leq}30{\mu}m$) with the same measurement accuracy, tho concept of the critical normalized contrast($VC_{critical}$) is applicable with 85% of the maximum normalized contrast value($VC_{max}$). Finally, the depth-of-field was checked for the size range between $10{\mu}m$ and $300{\mu}m$ when the both in-focus criteria ($GI_{critical}$ and $VC_{critical}$) were adopted. The change of the depth-of-field with the particle size shows good linearity in both the VC-applicable and the GI-applicable ranges with a reasonable accuracy.