• 한국군사과학기술학회지
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• 제25권6호
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• pp.553-560
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• 2022

This study investigates improvement of torsional strength of special wrench for K-series self-propelled howitzer power-pack maintenance. In order to maintain the power-pack, special wrench is one of the essential tools for assembling/disassemblimg the engine and transmission. However, failures(plastic deformation, fracture phenomenon and etc.) have been frequently reported even though special wrench was used within recommended standard torque range. Therefore, in this study, finite element analysis using ABAQUS was performed and modification of design parameters have been proposed. Prototypes based on the proposed parameters were manufactured and torsional experiment(torque about 130 % of recommend maximum torque) validated the newly proposed design parameters. Special wrench based on this study is applied to mass production and currently used for the maintenance.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집(한일합동학술편); 한국과학기술대학, 충남; 16-17 Oct. 1987
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• pp.932-938
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• 1987

The dynamic equations of robotic manipulators can be derived from either Newton-Euler equation or Lagrangian equation. Model parameters which appear in the resulting dynamic equation are the nonlinear functions of both the inertial parameters and the geometric parameters of robotic manipulators. The identification of the model parameters is important for advanced robot control. In the previous methods for the identification of the model parameters, the geometric parameters are required to be predetermined, or the robotic manipulators are required to follow some special motions. In this paper, we propose an approach to the identification of the model parameters, in which prior knowledge of the geometric parameters is not necessary. We show that the estimation equation for the model parameters can be formulated in an upper block triangular form. Utilizing the special structures, we obtain a simplified least-square estimation algorithm for the model parameter identification. To illustrate the practical use of our method, a 4DOF SCARA robot is examined.

• Journal of applied mathematics & informatics
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• 제36권5_6호
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• pp.541-553
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• 2018

We introduce q-special numbers and polynomials with q-exponential distribution. From these numbers and polynomials we derive some properties and identites. We also find approximated zeros of q-special polynomials and investigate property of two parameters ${\lambda}$, q.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.520-520
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• 2006

• Journal of the Korean Data and Information Science Society
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• 제18권4호
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• pp.963-972
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• 2007

When a control chart signals that a special cause is present, process engineers must initiate a search for and an identification of the special cause. Knowing the time of the process change could lead to identify the special cause more quickly, and to take the appropriate actions immediately to improve quality. In this paper, we propose the maximum likelihood estimator (MLE) for the process change point when a control chart is used in monitoring the parameters of a process in which the observations can be modeled as a first-order autoregressive(AR(1)) process plus an additional random error.

• 대한수학회논문집
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• 제37권1호
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• pp.207-212
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• 2022

In this paper, an interesting integral involving the Ī-function of one variable introduced by Rathie has been derived. Since Ī-function is a very generalized function of one variable and includes as special cases many of the known functions appearing in the literature, a number of integrals can be obtained by reducing the Ī function of one variable to simpler special functions by suitably specializing the parameters. A few special cases of our main results are also discussed.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 추계종합학술대회 논문집(1)
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• pp.357-360
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• 2000

This paper describes a parameter extraction method for HBT(Heterojunction Bipolar Transistor) equivalent circuit model without measurements of special test structures or numerical optimizations. Instead, all equivalent circuit parameters are calculated analytically from small-signal S-parameters measured under different bias conditions. These values being extracted from the cutoff mode can be used to extract intrinsic parameters at the active mode. This method yields a deviation of about 1.3 % between the measured and modeled S-parameters.

• Steel and Composite Structures
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• 제11권4호
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• pp.273-290
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• 2011

In current ductility-based earthquake-resistant design, the estimation of design forces continues to be carried out with the application of response modification factors on elastic design spectra. It is well-known that the response modification factor (R) takes into account the force reduction, strength, redundancy, and damping of structural systems. The key components of the response modification factor (R) are force reduction ($R_{\mu}$) and strength ($R_S$) factors. However, the response modification and strength factors for structural systems presented in design codes were based on professional judgment and experiences. A numerical study has been accomplished to evaluate force reduction, strength, and response modification factors for special steel moment resisting frames. A total of 72 prototype steel frames were designed based on the recommendations given in the AISC Seismic Provisions and UBC Codes. Number of stories, soil profiles, seismic zone factors, framing systems, and failure mechanisms were considered as the design parameters that influence the response. The effects of the design parameters on force reduction ($R_{\mu}$), strength ($R_S$), and response modification (R) factors were studied. Based on the analysis results, these factors for special steel moment resisting frames are evaluated.

• 시큐리티연구
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• 제45호
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• pp.87-106
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• 2015

이 연구에서는 특수경비원의 조직 내 의사소통이 직무만족과 직무몰입에 영향을 미치는데 있어서의 대인관계 능력의 매개효과를 살펴보기 위해 교육시설 공항 교통시설에서 근무하고 있는 특수경비원을 대상으로 2015년 9월 20일부터 2015년 10월 20일까지 설문조사를 실시하였다. 연구의 분석 결과는 다음과 같이 나타났다. 대인관계 능력 매개 효과 분석모형도는 포화모형도이며, 직무만족(직무몰입)에 대한 대인관계 능력의 매개 효과 분석 결과를 살펴보면, 대인관계와 의사소통의 수준이 높을수록 직무만족(직무몰입) 수준이 높게 나타났으며, 또한 대인관계에서 의사소통 수준이 높을수록 대인관계 수준도 높게 나타났다. SMC에서는 직무만족이 23.9%, 직무몰입이 11.6%, 대인관계는 19.3% 설명한다. 또한, 직무몰입에 대한 대인관계 능력의 매개 효과 분석의 결과는 의사소통이 직무만족(직무몰입)에 미치는 영향에 대인관계가 매개효과가 존재함을 확인할 수 있다. 의사소통이 대인관계에 미치는 직접효과는 통계적 유의도가 나타났다. 이 연구의 결과를 종합해 보면, 특수경비원의 조직 내 의사소통이 직무만족과 직무몰입에 영향을 미치는데 대인관계 능력의 매개 효과가 있는 것으로 나타났다.

• Journal of international Conference on Electrical Machines and Systems
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• 제1권2호
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• pp.18-22
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• 2012

This paper presents a method and the experimental measurement system for the determination of Jiles-Atherton model parameters of the 30ZH120 electrical steel sheet. The paper utilizes Epstein Square devices to proceed with the experiment and measurement on a group of hysteresis loops of some certain transformers which use the 30ZH120 electrical steel sheet under two different lap ways. The approach relies on the simulated annealing optimization method in order to minimize the error between the measured and modeled hysteresis curves and yield the best five Jiles-Atherton model parameters. A convenient program, based on the Simulink platform, that can identify the J-A model parameters automatically from the experimental saturated hysteresis loop which is used to model the nonlinear characteristics of the electrical steel sheet, is developed. Research shows that the simulated annealing optimization method gets satisfactory results.