• Title/Summary/Keyword: Complex Linkage

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The Effect of Prior Financial Performance on Organizational Reputation and Earnings Management

  • HUYNH, Quang Linh;NGUYEN, Nguyen Van
    • The Journal of Asian Finance, Economics and Business
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    • v.6 no.4
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    • pp.75-81
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    • 2019
  • The paper aims to investigate the linkage among prior financial performance, organizational reputation and earnings quality. Firstly, it examines the influence of prior financial performance on organizational reputation and on earnings quality. Secondly, this research explores the moderating role that prior financial performance plays in the causal relationship from organizational reputation to earnings quality. Thirdly, the mediating role of organizational reputation in the effect of prior financial performance on earnings quality is analyzed. The empirical findings show that, prior financial performance positively affects both earnings quality and organizational reputation that in turn partly mediates the causal connection from prior financial performance to earnings quality; whereas prior financial performance imposes a positive moderation in the influence of organizational reputation on earnings quality. This research is expected to provide scholars and practitioners with a thorough understanding of the complex link among prior financial performance, organizational reputation and earnings quality. That helps them to deliver good decisions on the investment of suitable resources in maintaining and enhancing their organizational reputation, which assures a higher quality of reported earnings that in turn improves involved stakeholders' confidence in their firm. This likely leads the firms to gain better performance in the future.

A Study on Adaptive Load Torque Observer for Robust Precision Position Control of BLDC Motor (적응제어형 외란 관측기를 이요한 BLDC 전동기의 정밀위치제어에 대한 연구)

  • 고종선;윤성구
    • Proceedings of the KIPE Conference
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    • 1999.07a
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    • pp.4-9
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    • 1999
  • A new control method for precision robust position control of a brushless DC (BLDC) motor using asymptotically stable adaptive load torque observer is presented in the paper. Precision position control is obtained for the BLDC motor system approximately linearized using the field-orientation method Recently, many of these drive systems use BLDC motors to avoid backlashe. However, the disadvantages of the motor are high cost and complex control because of nonlinear characteristics. Also, the load torque disturbance directly affects the motor shaft. The application of the load torque observer is published in [1] using fixed gain. However, the motor flux linkage is not exactly known for a load torque observer. There is the problem of uncertainty to obtain very high precision position control. Therefore a model reference adaptive observer is considered to overcome the problem of unknown parameter and torque disturbance in this paper. The system stability analysis is carried out using Lyapunov stability theorem. As a result, asymptotically stable observe gain can be obtained without affecting the overall system response. The load disturbance detected by the asymptotically stable adaptive observer is compensated by feedforwarding the equivalent current which gives fast response. The experimenta results are presented in the paper.

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Flat-type 와이퍼 블레이드의 내구 신뢰성 향상을 위한 연구

  • Jeong, Won-Seon;Seo, Yeong-Gyo;Kim, Hong-Jin;Jeong, Do-Hyeon
    • Proceedings of the Korean Reliability Society Conference
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    • 2011.06a
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    • pp.107-113
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    • 2011
  • The windshield wiper consists of 4 parts: a blade, an arm, a linkage and a motor. The wiper blade makes contact with the windshield and is designed to be operated normally at an angle of 30~50 degrees to the front glass. If the contact pressure between the wiper blade and windshield surface is too high, noise and wear of the rubber will result. On the other hand, if the contact pressure is too low, the performance will do badly, since foreign substances such as dust and stains will not be removed well. The pressure and friction of the wiper blade has a great influence on its effectiveness in cleaning the front window. This is due to the contact of the rubber with the window. This paper presents the dynamic analysis method to estimate the performance of the flat type blade of the wiper system. The blade has a nonlinear characteristic since the rubber is an incompressible hyper-elastic and visco-elastic material. Thus, Structural dynamic analysis using a complex contact model for the blade is performed to find the characteristics of the blade. The flexible multi-body dynamic model is verified by the comparison between test and analysis result. Also, the optimization using the central composite design table is performed.

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A Study on methodology of physical Fabrication & reorganization of Epidermis in Space Design - Focused on reorganization of Epidermis, Fabrication - (공간디자인에서 디지털 표피 재 조직화, 물리적 구현 방법 연구 - 표피 재 조직화, 가공 중심으로 -)

  • Park, Jeong-Joo
    • Korean Institute of Interior Design Journal
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    • v.17 no.2
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    • pp.150-161
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    • 2008
  • It requires more close cooperation process and mediator for smooth communication in this industry structure where design and engineers are separated. The database of design integrates separate system and helps connection between organizations. The application category is utilized variously from formation to operation. Architectures addressed in this content as Frank Gehry and Nox are making differentiated design on the base of 3d digital methodology and using it widely from generation to fabrication. Especially they got to be free from the generative limit as it became available to analyse, digital surface organization, and realize the complex system form. Now more integrated and delicate works got to be affordable owing to various kinds of improved CNC, RP(rapid-prototype) machines, and architecture hardwares. With a linkage of software now at their disposal, architects can create a digital model of a building and all of its design elements, and in turn use this 3d information to construct actual building components using machines driven by CNC and other advanced manufacturing techniques. Digital technologies are enabling a direct correlation between what design and construction, thus bringing to the forefront the issue of the significance of information, the production, communication, application, and control of digital information in the industrial system. The central requirement is the clear, reliable, and consistent exchange of information among all parties involved in creating a given project.

Heuristic Algorithm for Selecting Mutually Dependent Qualify Improvement Alternatives of Multi-Stage Manufacturing Process (다단계제조공정의 품질개선을 위한 종속대안선택 근사해법)

  • 조남호
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.11 no.18
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    • pp.7-15
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    • 1988
  • This study is concerned with selecting mutually dependent quality improvement alternatives with resource constraints. These qualify improvement alternatives art different fro the tradition at alternatives which are independent from each other. In other words, selection of any improvement alternative requires other related specific improvement. Also the overall product quality in a multi stage manufacturing process is characterized by a complex multiplication method rather than a simple addition method which dose not allow to solve a linear knapsack problem despite its popularity in the traditional study. This study suggests a non-linear integer programming model for selecting mutually dependent quality improvement alternatives in multi-stage manufacturing process. In order to apply the model to selecting alternatives. This study also suggests a heuristic mode1 based on a dynamic programming model which is more practical than the non-linear integer programming model. The logic of the heuristic model enables 1) to estimate improvement effectiveness values on all improvement alternatives specifically defined for this study. 2) to arrange the effectiveness values in a descending order, and 3) to select the best one among the alternatives based on their forward and backward linkage relationships. This process repeats to selects other best alternatives within the resource constraints. This process is presented in a Computer programming in Appendix A. Alsc a numerical example of model application is presented in Chapter 4.

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Experimental Results of Adaptive Load Torque Observer and Robust Precision Position Control of PMSM (PMSM의 정밀 Robust 위치 제어 및 적응형 외란 관측기 적용 연구)

  • Go, Jong-Seon;Yun, Seong-Gu
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.49 no.3
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    • pp.117-123
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    • 2000
  • A new control method for precision robust position control of a PMSM (Permanent Magnet Synchronous Motor) using asymptotically stable adaptive load torque observer is presented in the paper. Precision position control is obtained for the PMSM system approximately linearized using the field-orientation method. Recently, many of these drive systems use the PMSM to avoid backlashes. However, the disadvantages of the motor are high cost and complex control because of nonlinear characteristics. Also, the load torque disturbance directly affects the motor shaft. The application of the load torque observer is published in [1] using fixed gain. However, the motor flux linkage is not exactly known for a load torque observer. There is the problem of uncertainty to obtain very high precision position control. Therefore, a model reference adaptive observer is considered to overcome the problem of unknown parameter and torque disturbance in this paper. The system stability analysis is carried out using Lyapunov stability theorem. As a result, asymptotically stable observer gain can be obtained without affecting the overall system response. The load disturbance detected by the asymptotically stable adaptive observer is compensated by feedforwarding the equivalent current which gives fast response. The experimental results are presented in the paper using DSP TMS320c31.

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A Study of Advanced Spherical Motor for Improvement of Multi-DOF Motion

  • Park, Hyun-Jong;Cho, Su-Yeon;Ahn, Han-Woong;Lee, Ho-Jun;Won, Sung-Hong;Lee, Ju
    • Journal of Electrical Engineering and Technology
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    • v.7 no.6
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    • pp.926-931
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    • 2012
  • Since robot industry growing, the machine that could move with multi-DOF has been studied in many industrial fields. Spherical motor is one of the multi-DOF machine that doesn't need gear for multi-DOF motion. Unlike conventional motor, spherical motor can not only rotate on the shaft axis (rotating motion), but tilt the shaft with 2-DOF motion (positioning motion). In the typical type of spherical motor, one coil took part in positioning motion and rotating motion at the same time. As the result, the control algorithm was complex. To solve this problem, this study proposed a novel type of coil on the stator. The coils were separated for positioning motion and rotating motion. Thus the linkage flux of rotating coil didn't be affected the positioning angle. In this paper, comparing the back-EMF of typical and novel type was conducted and the driving experiment was carried out as the positioning angle. From the experiment result, the performance of proposed spherical motor could be verified.

Simulation of the Reduction of Force Ripples of the Permanent Magnet Linear Synchronous Motor

  • Chung, Koon-Seok;Zhu, Yu-Wu;Lee, In-Jae;Lee, Kwon-Soon;Cho, Yun-Hyun
    • Journal of Electrical Engineering and Technology
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    • v.2 no.2
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    • pp.208-215
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    • 2007
  • The significant drawback of the permanent magnet linear synchronous motor (PMLSM) is force ripples, which are generated by the distortion of the stator flux linkage distributions, cogging forces caused by the interaction of the permanent magnet and the iron core and the end effects. This will deteriorate the performance of the drive system in high precision applications. The PMLSM and its parasitic effects are analyzed and modeled using the complex state-variable approach. To minimize the force ripple and realize the high precision control, the components of force ripples are extracted first and then compensated by injecting the instantaneous current to counteract the force ripples. And this method of the PMLSM system is realized by the field oriented control method. In order to verify the validity of this proposed method, the system simulations are carried out and the results are analyzed. The effectiveness of the proposed force ripples reduction method can be seen according to the comparison between the compensation and non-compensation cases.

Design and Implementation of JPP(JNI Preprocessor) (JPP(JNI 전처리기)의 설계 및 구현)

  • Lee, Chang-Hwan;O, Se-Man
    • The KIPS Transactions:PartA
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    • v.9A no.1
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    • pp.129-136
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    • 2002
  • JNI is a linkage method to other languages such as C/C++ which enables the Java to do the platform-dependent specific tasks and also, it can be used to reuse the existing libraries and programs. However, the complex and difficult steps are required to use JNI and it is Inconvenient to manipulate Java source and C/C++ source separately. We design and implement the JPP (Java Preprocessor) that enables the Java source and C/C++ source to handle in a same source file and reduces the required steps so as to use JNI easily.

Structural Analysis of Water Soluble Lignin-Carbohydrate Complex(LCC) Isolated from Korean Camellia Mistletoe(Pseudixus japonicus Hayata) (한국산 동백나무겨우살이에서 추출한 수용성 리그닌-탄수화물 복합체의 구조분석)

  • Choi, Joon-Weon;Ahn, Won-Yung
    • Journal of the Korean Wood Science and Technology
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    • v.25 no.3
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    • pp.1-7
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    • 1997
  • 한국산 동백나무겨우살이(Pseudixus japonicus Hayata)에 존재하는 수용성 리그닌-탄수화물 복합체를 구성하는 다당류의 구조를 밝히고 리그닌 성분과 다당류의 결합양식을 구명하고자, 냉 온수 추출한 수용성 리그닌-탄수화물 복합체(M-LCC-WE)를 DEAE Sephadex A-50로 중성분획(M-LCC-N)과 산성분획(M-LCC-A), 나머지분획(M-LCC-R)으로 세분화한 후 M-LCC-N과 M-LCC-A에 대하여 메틸화, 아세틸화, 그리고 DDQ 산화반응을 실시하였다. M-LCC-N을 구성하는 다당류는 ($1{\rightarrow}4$) 글리코시드결합의 arabinan과 ($1{\rightarrow}4$)나 ($1{\rightarrow}6$) 글리코시드결합의 galactan과 glucan으로 M-LCC-A의 다당류는 ($1{\rightarrow}4$) 글리코시드결합의 arabinan과 ($1{\rightarrow}6$) 글리코시드결합의 galactan이 다당류 주성분으로 밝혀졌으며 galacturonic acid가 결합되어 있기 때문에 산성적 성질을 나타내고 있었다. 또한 M-LCC-A에서는 galacturonic acid 의 carboxyl 그룹이 리그닌의 ${\alpha}$-와 ${\gamma}$-위치에서 ester결합이 존재함이 확인되었다.

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