• Title/Summary/Keyword: 역구조 결함

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Experimental study on new artificial reef for hydraulic stability (해조류 이식형 인공어초의 수리적 안정성에 관한 실험적 검토)

  • Shin, Bum-Shick;Chung, Hyun-Joon;Kim, Kyu-Han
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.1
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    • pp.555-560
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    • 2014
  • In Korea, quantitative growth rate of artificial reef construction is supposed to reach the peak point therefore, new approach is needed to the point of artificial reefs business. Functional reefs like shellfish reefs, recreational reefs, seaweed reefs as well as fish reefs are beneficial alternatives. This study conducted hydraulic testing to assess the stability of new types of artificial reefs (ARs) constructed to promote the growth of shellfish and seaweed. The results of this study revealed that some dimensionless design parameters affected the stability of new types of artificial reef under various wave and water depth conditions in the fixed bed condition. The findings also highlight the importance of hydraulic experiments in solving problems that have emerged in the design and construction of artificial reefs.

A Study of the relationship of Empowerment Leader Behavior and directed of individual and organization OCB (임파워먼트 리더 행위와 개인 및 조직지향 조직시민행동의 관계에 관한 연구)

  • Ku, Seung-Deug;Lee, Sun-Kyu;Kang, Eun-Gu
    • Journal of Digital Convergence
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    • v.15 no.11
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    • pp.155-165
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    • 2017
  • This study divides organizational citizenship behaviors into two dimensions, organizational and individual, in order to clarify the out-role behaviors of organizational members more specifically. In addition, we selected Empowering leadership as an input factor that can lead to organizational citizenship behavior and examined the mediating role of trust. To accomplish this purpose, the authors conducted a survey of employees in manufacturing companies in the Daegu-Gyeongbuk region and the hypothesis was verified through structural equations model. The results of the study are as follows. Empowering leadership has a significant positive impact on OCB-O and OCB-I. Also, Trust has been found to partial mediate effect the relationship between empowering leadership and OCB_O and OCB_I. The results of this study will be specific guidelines for inducing organizational citizenship behavior in organizations, and will further expand the scope of research into organizational citizenship behavior.

Using the On-Package Memory of Manycore Processor for Improving Performance of MPI Intra-Node Communication (MPI 노드 내 통신 성능 향상을 위한 매니코어 프로세서의 온-패키지 메모리 활용)

  • Cho, Joong-Yeon;Jin, Hyun-Wook;Nam, Dukyun
    • Journal of KIISE
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    • v.44 no.2
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    • pp.124-131
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    • 2017
  • The emerging next-generation manycore processors for high-performance computing are equipped with a high-bandwidth on-package memory along with the traditional host memory. The Multi-Channel DRAM (MCDRAM), for example, is the on-package memory of the Intel Xeon Phi Knights Landing (KNL) processor, and theoretically provides a four-times-higher bandwidth than the conventional DDR4 memory. In this paper, we suggest a mechanism to exploit MCDRAM for improving the performance of MPI intra-node communication. The experiment results show that the MPI intra-node communication performance can be improved by up to 272 % compared with the case where the DDR4 is utilized. Moreover, we analyze not only the performance impact of different MCDRAM-utilization mechanisms, but also that of core affinity for processes.

Angular Kinematic Analysis of Forehand Drive and Smash in Table Tennis (탁구 포핸드 드라이브와 스매시의 각운동학 분석)

  • Son, Won-Il
    • Korean Journal of Applied Biomechanics
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    • v.18 no.1
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    • pp.11-19
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    • 2008
  • This study was conducted with 8 male table tennis players who won national competitions. Of the subjects, 4 used a racket of penholder grip and 4 used one of shake hand grip, and all of them were right.handers. We analyzed three-dimensional angular characteristics such as angular component, swing trajectory and swing posture related to the racket swing motions of forehand drive and smash in table tennis, and drew conclusions as follows. Racket angle(p<.05) and racket swing angle(p<.01) were significantly different between the two motions. In smash, the back swing posture maintained the racket angle large by holding the racket upright and made the racket swing angle small for high ball speed. In addition, the height of the racket head in back swing posture was also significantly different between the two motions. In phg on impact, the open angle of the long axis of the racket was significantly different between the two motions. This shows that impact was applied a bit behind for giving top spin to the ball. In the back swing of drive, the gradient of the upper body was slightly larger in shg than in phg probably because of the structural difference of the racket grip in the neutral posture.

Analyses of Patterns of Spins with Insole Foot-Pressure Distribution during a Figure Skating (Flying Sit Spin과 Flying Camel Spin 시 규정자세에 따른 족저압력패턴의 연구)

  • Yoo, Kyoung-Seok
    • Korean Journal of Applied Biomechanics
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    • v.18 no.1
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    • pp.159-168
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    • 2008
  • The purpose of this study was to analyze the variables of plantar pressure distribution, the COG between Flying Sit Spin(FSS) and Flying Camel Spin(FCS) during a Figure Skating. In order to investigate the two types of spin mechanism in the Korea national of elite women Figure skaters(N=4), this study investigated the phase time, CA(contact area), MF(maximum force) Mean Force, and PP(peak pressure) Mean Force. The data was collected using PEDAR Mobile System which is the pressure distribution measuring devices. The obtained conclusions were as follow: During the two types of spins(FSS and FCS), the FCS is higher than the FSS on the MF(20%BW), PP(20%BW) variables during P4 phase, but the FSS is larger than the FCS in the CA, MF, and PP during P1, P2, P3 phase. Consequently, depend on the COP and the COG locations about the vertical ground reaction vector, the FCS comparatively excelled control of speed feedback than the FSS in the P4 phase.

A Low Power Single-End IR-UWB CMOS Receiver for 3~5 GHz Band Application (3~5 GHz 광대역 저전력 Single-Ended IR-UWB CMOS 수신기)

  • Ha, Min-Cheol;Park, Byung-Jun;Park, Young-Jin;Eo, Yun-Seong
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.20 no.7
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    • pp.657-663
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    • 2009
  • A fully integrated single ended IR-UWB receiver is implemented using 0.18 ${\mu}m$ CMOS technology. The UWB receiver adopts the non-coherent architecture, which simplifies the RF architecture and reduces power consumption. The receiver consists of single-ended 2-stage LNAs, S2D, envelope detector, VGA, and comparator. The measured results show that sensitivity is -80.8 dBm at 1 Mbps and BER of $10^{-3}$. The receiver uses no external balun and the chip size is only $1.8{\times}0.9$ mm. The consumed current is very low with 13 mA at 1.8 V supply and the energy per bit performance is 23.4 nJ/bit.

Composite Right/Left Handed(CRLH) Transmission Line with Controllable Transmission Zeros (제어 가능한 전송 영점을 갖는 CRLH 전송 선로)

  • Lee, Ja-Hyeon;Kim, Kyoung-Keun;Lim, Yeong-Seog
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.21 no.6
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    • pp.583-590
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    • 2010
  • In this paper, a novel CRLH-TL unit cell with controllable transmission zeros was proposed. Proposed composite right/left handed transmission line(CRLH-TL) unit cell is implemented in the form of the metal-insulator-metal(MIM) capacitors, the microstrip stub inductors, and the co-planar waveguide(CPW) inductor. And this proposed CRLH-TL generates two transmission zeros in lower/upper passband by the effort of electromagnetic couplings between each MIM capacitors and microstrip stub inductors. Using this proposed CRLH-TL, broad bandpass filter for UWB system was designed and fabricated. The measured results reveal that the two transmission zeros are observed in lower/upper passband and the overall size of the filter, excluding the feed line is about 8 mm$\times$8 mm, less then $\lambda_g$/4 on electric size.

Cross-Sectional Velocity Variability and Tidal Exchanger in a Bay (만구를 통한 해수유출입과 만내수괴의 해수교환성)

  • 김종화
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.26 no.4
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    • pp.353-359
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    • 1990
  • Chinhae Bay, included small ports, is the region which the red tide phenomenon is occurred frequently in summer season. Field sampling of 4 cross-sections in the bay resulted in detailed informations on cross-sectional velocity distributions, salt concentrations and discharge during one consecutive tidal cycle in summer season, 1983. High velocity cores reoccur two times a semi-diurnal tidal cycle at the same cross-sectional location, lower layer, in Kadok Channel during the spring tide. The tidal exchange ratio was estimated by Eulerian method. The range of exchange ratios in central Kadok Channel are 9.3-17% at the spring tide and 16.9-21.8% at the neap tide. On the other hand, its range in Masan bay-mouth is 8.7% at the spring tide and 2.0% neap tide, respectively.

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Bayesian analysis of latent factor regression model (내재된 인자회귀모형의 베이지안 분석법)

  • Kyung, Minjung
    • The Korean Journal of Applied Statistics
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    • v.33 no.4
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    • pp.365-377
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    • 2020
  • We discuss latent factor regression when constructing a common structure inherent among explanatory variables to solve multicollinearity and use them as regressors to construct a linear model of a response variable. Bayesian estimation with LASSO prior of a large penalty parameter to construct a significant factor loading matrix of intrinsic interests among infinite latent structures. The estimated factor loading matrix with estimated other parameters can be inversely transformed into linear parameters of each explanatory variable and used as prediction models for new observations. We apply the proposed method to Product Service Management data of HBAT and observe that the proposed method constructs the same factors of general common factor analysis for the fixed number of factors. The calculated MSE of predicted values of Bayesian latent factor regression model is also smaller than the common factor regression model.

Optimal Parameters Estimation of Diffusion-Analogy Geomorphologic Instantaneous Unit Hydrograph Model (확산-유추 지형학적 순간단위도 모형의 최적매개변수 추정)

  • Kim, Joo-Cheol;Choi, Yong-Joon
    • Journal of Wetlands Research
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    • v.13 no.3
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    • pp.385-394
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    • 2011
  • In this study, optimal parameters of diffusion-analogy GIUH were calculated by separating channel and hillslope from drainage structures in the basin. Parameters of the model were composed of channel and hillslope, each velocity($u_c$, $u_h$) and diffusion coefficient($D_c$, $D_h$). Tanbu subwatershed in Bocheong river basin as a target basin was classified as 4th rivers by Strahler's ordering scheme. The optimization technique was applied to the SCE-UA, the estimated optimal parameters are as follows. $u_c$ : 0.589 m/s, $u_h$ : 0.021 m/s, $D_c$ : $34.469m^2/s$, $D_h$ : $0.1333m^2/s$. As a verification for the estimated parameters, the error of average peak flow was about 11 % and the error of peaktime was 0.3 hr. By examining the variability of parameters, the channel diffusion coefficient didn't have significant effect on hydrological response function. by considering these results, the model is expected to be simplified in the future.