• Title/Summary/Keyword: bounds

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Sharing Error Allowances for the Analysis of Approximation Schemes (근사접근법 분석을 위한 오차허용치의 분배방법)

  • Kim, Joon-Mo;Goo, Eun-Hee
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.46 no.5
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    • pp.1-7
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    • 2009
  • When constructing various mobile networks including sensor networks, the problem of finding the layout or graph to interconnect the terminals or nodes of the network may come up. Providing a common scheme that can be applied to the kind of problems, and formulating the bounds of the run time and the result of the algorithm from the scheme, one may evaluate precisely the plan of constructing analogous network systems. This paper, dealing with EMST(Euclidean Minimum Spanning Tree) that represents such problems, provides the scheme for constructing EMST by parallel processing over distributed environments, and the ground for determining the maximum difference of the layout or the graph produced from the scheme: the difference from EMST. In addition, it provides the upper bound of the run time of the algorithm from the scheme.

A Study of the Make-up Aesthetic Characteristics in Techno-Cyber Fashion (테크노-사이버 패션에서의 메이크업의 미적 특성)

  • Chung Kwi-Sook;Cho Kyoung-Hee
    • Journal of the Korean Society of Costume
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    • v.54 no.7
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    • pp.63-78
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    • 2004
  • The purpose of this study examines the characteristics of the Techno-Cyber fashion in modern fashion, and especially, how the make-up in the Techno-Cyber fashion is expressed artistically, and finally how much the make-up has its aesthetic value and significance. This study has its meaning in studying the relationship between the Techno-Cyber fashion and the make-up. Further more, the study has its significance in that it is possible to consider the interaction of the make-up by the fashion trend. The way of the study is to analyze its features that are shown in the documents of the inside and outside of the country. the study precedent, the technical journal, and the fashion picture. And also the study refers to the related contents in the searching for internet. The aesthetic characteristics of the expressed make-up is shown with the various aesthetic styles, as follows : First, the future-oriented characteristics is shown as the expression of the metallic make-up that emphasizes the glitter and glossy texture, and of the transparent make-up that emphasizes the simplicity of the body. Second, the surrealistic characteristics is expressed to the collage make-up that expresses the unexpected character with the introduction of the special materials and the position changing and the graphic make-up that destroys the standardized form. Third, the anti-cultural characteristics is expressed to the Cyber-Punk make-up that expresses the destructive and challenging image. Finally, the compromise characteristics is shown in the Ethno make-up combined the concept of the ethnic with the high technology and the Androgynous make-up which destroys the bounds of the sex.

Optimal Design of Reinforced Concrete Frames using Sensitivity Analysis (설계민감도를 이용한 철근콘크리트 뼈대구조의 최적화)

  • Byun, Keun Joo;Choi, Hong Shik
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.9 no.1
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    • pp.33-40
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    • 1989
  • In the design of reinforced concrete framed structures, which consist of various design variables, the objective and the constraint functions are formulated in complicated forms. Usually iterative methods have been used to optimize the design variables. In this paper, multilevel formulation is adopted, and design variables are selected in reduced numbers at each level, to reduce the iterative cycle and to accelerate the convergence rate. At level 1, elastic analysis is performed to get the upper and lower bounds of the redistributed design moments due to inelastic behavior of the frame. Then the design moments are taken as design variables and optimized at level 2, and the sizing variables are optimized at level 3. The optimization of redistributed moments is performed using the design sensitivity obtained at the level 2, and force approximation technique is used to reflect the variation of design variables in the lower level to the upper level. The design variables are selected in reduced numbers at each level, and the optimization formulation is simplified effectively. A cost function is taken as the objective function, and the constraints of the stress of the structures are derived from BSI CP 110 following limit state theory. Numerical examples are included to prove the effectiveness of the developed algorithm.

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Analyzing the Status of Students' Learning on Mathematics Related Contents of Animal Resources Curriculum in Agricultural High School (농업계 특성화고 동물자원과 전공 교과목에 제시된 수학 관련 내용 및 이에 대한 학생들의 학습 실태 분석)

  • Cho, Eun Ah;Do, Jonghoon;Park, Yun Beom
    • Journal of the Korean School Mathematics Society
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    • v.20 no.2
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    • pp.77-89
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    • 2017
  • Although it is not necessary to have much mathematical knowledge in Major Courses of Animal Resources curriculums in agricultural high school, the function of mathematics class has a much effect on Major Courses. Therefore, we extracted the mathematics contents included in Major Courses of Animal Resources curriculums in agricultural high school, and also evaluated students' understanding according to the description method in textbooks of Major Courses. Furthermore, we analyzed students' preference about the description method in textbooks related to the Major Courses. As a result, it turns out that the level of mathematics contents of Animal Resources major curriculums does not break bounds of middle school level. Furthermore, many students are not able to solve the middle school level of problems. It is also shown that the most preferred description method in textbooks of Animal Resources major curriculums is the sentence-equation mixed type. In this study, we propose to reconstruct the mathematics contents with basic knowledge needed to complete the Major Courses in order that students can complete them more easily, and furthermore, to choose the description method in textbooks of Major Courses as sentence-equation mixed type and detailed explanation about terms should be included into the bargain.

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Molecular Discrimination of Dinoflagellates Cochlodinium Polykrikoides Margalef, Gyrodinium Impudicum Fraga et Bravo and Gymnodinium Catenatum Graham using RAPD-PCR Method (RAPD-PCR 방법을 이용한 Cochlodinium polykrikoides Gyrodinium impudicum, Gymnodinium catenatum의 분자생물학적 진단)

  • Cho, Eun-Seob
    • Journal of Life Science
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    • v.13 no.5
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    • pp.651-657
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    • 2003
  • Randomly amplified polymorphic DNA (RAPD) analysis was used to study genetic relationships among C. polykrikoides, G. impudicum and G. catenatum, which possess similar morphological features. Four of 12 primers were selected and 59 amplification products ranged from 0.2 kb to 3.0 kb. The number of polymorphic products in C. polykrikoides, G. impudicum and G. catenatum was 16 (27.1%), 8 (13.5%), and 16 (27.1%), respectively, while 17 were monomorphic. Number of species-specific bounds was 26 (44.0%), 34 (57.6%), 26 (44.0%) in C. polykrikoides, G. impudicum and G. catenatum, respectively. The genetic similarity between C. polykrikoides and G. impudicum/G. catenatum was 0.83, whereas G. impudicum and G. catenatum was 0.78. Our results suggest that C. polykrikoides, G. impudicum and G. catenatum are extremely different on the basis of RAPD analysis, despite similarity based on their morphology. The RAPD technique appears to be efficient in detecting genetic variation in these dinoflagellates.

Optimal Design Of Multisite Batch-Storage Network under Scenario Based Demand Uncertainty (다수의 공장을 포함하는 불확실한 수요예측하의 회분식 공정-저장조 망의 최적설계)

  • 이경범;이의수;이인범
    • Journal of Institute of Control, Robotics and Systems
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    • v.10 no.6
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    • pp.537-544
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    • 2004
  • An effective methodology is reported for determining the optimal lot size of batch processing and storage networks which include uncertain demand forecasting. We assume that any given storage unit can store one material type which can be purchased from suppliers, internally produced, infernally consumed, transported to or from other sites and/or sold to customers. We further assume that a storage unit is connected to all processing and transportation stages that consume/produce or move the material to which that storage unit is dedicated. Each processing stage transforms a set of feedstock materials or intermediates into a set of products with constant conversion factors. A batch transportation process can transfer one material or multiple materials at once between sites. The objective for optimization is to minimize the probability averaged total cost composed of raw material procurement, processing setup, transportation setup and inventory holding costs as well as the capital costs of processing stages and storage units. A novel production and inventory analysis formulation, the PSW(Periodic Square Wave) model, provides useful expressions for the upper/lower bounds and average level of the storage inventory. The expressions for the Kuhn-Tucker conditions of the optimization problem can be reduced to two sub-problems. The first yields analytical solutions for determining lot sires while the second is a separable concave minimization network flow subproblem whose solution yields the average material flow rates through the networks for the given demand forecast scenario. The result of this study will contribute to the optimal design and operation of the global supply chain.

Indirect Kalman Filter based Sensor Fusion for Error Compensation of Low-Cost Inertial Sensors and Its Application to Attitude and Position Determination of Small Flying robot (저가 관성센서의 오차보상을 위한 간접형 칼만필터 기반 센서융합과 소형 비행로봇의 자세 및 위치결정)

  • Park, Mun-Soo;Hong, Suk-Kyo
    • Journal of Institute of Control, Robotics and Systems
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    • v.13 no.7
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    • pp.637-648
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    • 2007
  • This paper presents a sensor fusion method based on indirect Kalman filter(IKF) for error compensation of low-cost inertial sensors and its application to the determination of attitude and position of small flying robots. First, the analysis of the measurement error characteristics to zero input is performed, focusing on the bias due to the temperature variation, to derive a simple nonlinear bias model of low-cost inertial sensors. Moreover, from the experimental results that the coefficients of this bias model possess non-deterministic (stochastic) uncertainties, the bias of low-cost inertial sensors is characterized as consisting of both deterministic and stochastic bias terms. Then, IKF is derived to improve long term stability dominated by the stochastic bias error, fusing low-cost inertial sensor measurements compensated by the deterministic bias model with non-inertial sensor measurement. In addition, in case of using intermittent non-inertial sensor measurements due to the unreliable data link, the upper and lower bounds of the state estimation error covariance matrix of discrete-time IKF are analyzed by solving stochastic algebraic Riccati equation and it is shown that they are dependant on the throughput of the data link and sampling period. To evaluate the performance of proposed method, experimental results of IKF for the attitude determination of a small flying robot are presented in comparison with that of extended Kaman filter which compensates only deterministic bias error model.

A Die-matching Method for 3D Memory Yield Enhancement considering Additional Faults during Bonding (3차원 메모리의 수율 증진을 위해 접합 공정에서 발생하는 추가 고장을 고려한 다이 매칭 방법)

  • Lee, Joo-Hwan;Park, Ki-Hyun;Kang, Sung-Ho
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.48 no.7
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    • pp.30-36
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    • 2011
  • Three-dimensional (3D) memories using through-silicon vias (TSVs) as vertical bus across memory layers are implemented by many semiconductor companies. 3D memories are composed of known-good-dies (KGDs). If additional faults are arisen during bonding, they should be repaired. In order to enhance the yield of 3D memories with inter-die redundancies, a die-matching method is needed to effectively stack memory dies in a 3D memory. In this paper, a new die-matching method is proposed for 3D memory yield enhancement with inter-die redundancies considering additional faults arisen during bonding. Three boundary-limited conditions are used in the proposed die-matching method; they set bounds to the search spaces for selecting memory dies to manufacture a 3D memory. Simulation results show that the proposed die-matching method can greatly enhance the 3D memory yield.

Modified parity space averaging approaches for online cross-calibration of redundant sensors in nuclear reactors

  • Kassim, Moath;Heo, Gyunyoung
    • Nuclear Engineering and Technology
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    • v.50 no.4
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    • pp.589-598
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    • 2018
  • To maintain safety and reliability of reactors, redundant sensors are usually used to measure critical variables and estimate their averaged time-dependency. Nonhealthy sensors can badly influence the estimation result of the process variable. Since online condition monitoring was introduced, the online cross-calibration method has been widely used to detect any anomaly of sensor readings among the redundant group. The cross-calibration method has four main averaging techniques: simple averaging, band averaging, weighted averaging, and parity space averaging (PSA). PSA is used to weigh redundant signals based on their error bounds and their band consistency. Using the consistency weighting factor (C), PSA assigns more weight to consistent signals that have shared bands, based on how many bands they share, and gives inconsistent signals of very low weight. In this article, three approaches are introduced for improving the PSA technique: the first is to add another consistency factor, so called trend consistency (TC), to include a consideration of the preserving of any characteristic edge that reflects the behavior of equipment/component measured by the process parameter; the second approach proposes replacing the error bound/accuracy based weighting factor ($W^a$) with a weighting factor based on the Euclidean distance ($W^d$), and the third approach proposes applying $W^d$, TC, and C, all together. Cold neutron source data sets of four redundant hydrogen pressure transmitters from a research reactor were used to perform the validation and verification. Results showed that the second and third modified approaches lead to reasonable improvement of the PSA technique. All approaches implemented in this study were similar in that they have the capability to (1) identify and isolate a drifted sensor that should undergo calibration, (2) identify a faulty sensor/s due to long and continuous missing data range, and (3) identify a healthy sensor.

Study on Wear of Journal Bearings during Start-up and Coast-down Cycles of a Motoring Engine - II. Analysis Results (모터링 엔진의 시동 사이클 및 시동 정지 사이클에서 저어널베어링의 마모 연구 - II. 해석 결과)

  • Chun, Sang Myung
    • Tribology and Lubricants
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    • v.31 no.3
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    • pp.125-140
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    • 2015
  • In this paper, we present the results of the wear analysis of journal bearings on a stripped-down single-cylinder engine during start-up and coast-down by motoring. We calculate journal bearing wear by using a modified specific wear rate considering the fractional film defect coefficient and load-sharing ratio for the asperity portion of a mixed elastohydrodynamic lubrication (EHL) regime coupled with previously presented graphical data of experimental lifetime linear wear in radial journal bearings. Based on the calculated wear depth, we obtain a new oil film thickness for every crank angle. By examination of the oil film thickness, we determine whether the oil film thickness at the wear scar region is in a mixed lubrication regime by comparing dimensionless oil film thickness, h/σ, to 3.0 at every crank angle. We present the lift-off speed and the crank angles involved with the wear calculation for bearings #1 and #2. The dimensionless oil film thickness, h/σ, illustrates whether the lubrication region between the two surfaces is still within the bounds of the mixed lubrication regime after scarring of the surface by wear. In addition, we present in tables the asperity contact pressure, the real minimum film thickness at the wear scar region, the modified specific wear rate, and the wear angle, α, for bearings #1 & #2. To show the real shape of the oil film at wear scar region, we depict the actual oil film thickness in graphs. We also tabulated the ranges of bearing angles related with wear scar. We present the wear volume for bearings #1 and #2 after one turn-on and turn-off of the engine ignition switch for five kinds of equivalent surface roughness. We show that the accumulated wear volume after a single turn-on and turn-off of an ignition switch normally increases with increasing surface roughness, with a few exceptions.