• Tunnel and Underground Space
• /
• v.11 no.2
• /
• pp.182-189
• /
• 2001

Rockmass properties have great influence on blasting performance so that it cannot be overemphasized to analyze rockmass properties and to perform blast design based on them. Up to the present, however blast design is performed either considering only uniaxial compressive strength of intact rock or using RMR classification as a blast ability classification scheme. In this paper Ashby's approach is adopted to evaluate blast index. In addition. rockmass classification for the blast design based on joint survey results and pattern design procedure are added to Ashby's original approach. With this extended approach, blastability can be classified considering joint properties and objectiveness of evaluated blast index can be confirmed. This approach is anticipated to enhance the tunnel blast design by considering joint properties and classifying the rockmass for blast design.

• International Journal of Control, Automation, and Systems
• /
• v.5 no.6
• /
• pp.691-700
• /
• 2007

This paper proposes a simple but effective design method of PID control using a numerical optimization method. In order to achieve both stability and performance, gain and phase margins and performance indices of step response directly compose of the cost function. Hence, the proposed approach is a multiobjective optimization problem. The main effectiveness of this approach results from the strong capability of the used optimization method. A one-dimensional example concerning gain margin illustrates the practical applicability of the optimization method. The present approach has many degrees of freedom in controller design by only adjusting related weight constants. The attained PID controller is compared with Wang#s and Ho#s methods, IAE, and ISE for a high-order process, and the simulation result for various design targets shows that the proposed approach achieves desired time-domain performance with a guarantee of frequency-domain stability.

• Proceedings of the KSME Conference
• /
• 2007.05a
• /
• pp.1760-1765
• /
• 2007

This paper shows a derating design approach for LED reliability improvement. The LED is widely used in display devices or circuits. The main failure of interest is defined as 100% reduction of the light output intensity of LED resulting from corrosion due to stresses, i.e. temperature and humidity. The lifetime is varied according to the stress levels under where the LED operates so that correlation of the lifetime to these stress levels over time is modeled through accelerated life testings. A derating design approach to accomplish a required reliability level of LED is proposed to determine adequate the stress levels. In the approach, $B_{10}$ life, Failure rate, Sensitivity Analysis of LED are used as a reliability metric.

• Industrial Engineering and Management Systems
• /
• v.7 no.3
• /
• pp.266-287
• /
• 2008

To manage collaborative negotiation in software system design, we have built a socio-technical argument-based negotiation management approach by integrating a Socio-technical Co-construction Process (STCP) with an Argument-based Negotiation Process (ABNP). This paper reviews relevant research work and presents each step of this approach. The STCP provides rich contextual information of technical decisions and social interactions in a system design process. The ABNP provides STCP with a negotiation management and conflict resolution strategy by guiding software engineers to generate, exchange and evaluate their argument claims in negotiation activities. In addition, this paper describes a prototype system which implements this new approach using the advanced Web-based software technologies with the goal of demonstrating how to systematically enhance the negotiation management capabilities in a dynamic socio-technical framework.

• Journal of Distribution Science
• /
• v.12 no.5
• /
• pp.93-107
• /
• 2014

Purpose - The pool of entrepreneurs with progressive qualities such as creativity and innovation was considered concurrently with such factors as work and capital that stimulate economic development and growth. This study aims to present a model to support the development of a strategic approach for achieving an overall academic entrepreneurship system in Iran. Research design, data, and methodology - The research design of this study is based on applied research because of its objectives, using principles and techniques formulated for basic research to solve operational and real organizational issues. This design also drives the method used, describing and interpreting the findings. Secondary data (library research) was used for this study's data collection. Because of this research's essential characteristics, no hypothesis is launched, and no research setting, questionnaire design, population or population sampling, validity or reliability tests, or statistical analysis are needed. Results and Conclusions - The model is created using a strategic approach acting in an octal setting comprising social, cultural, legal, economic, political, technological, competitive, and natural environments to present a conceptual framework for future studies.

• Korean Journal of Computational Design and Engineering
• /
• v.6 no.4
• /
• pp.254-262
• /
• 2001

It is not possible to exchange parametric information of CAD (Computer Aided Design) models based on the current version of STEP (Standard leer the Exchange of Product model data). The design intent can be lost during the STEP transfer of CAD models. The ISO Parametrics Group has proposed the SMCH (Solid Model Construction History) schema in June 2000 that includes structures fur exchange of parametric information. This paper proposes the macro parametric approach that is intended to provide capabilities to transfer parametric information. In this approach, CAD models are exchanged in the form of macro files. The macro file contains user commands which are used in the modeling phase. To exchange CAD models using the macro parametric approach, modeling commands of commercial CAD systems are analyzed. Those commands are classified by the grouping method suggested by Bill Anderson. As a neutral file format, a standard modeling commands set has been defined. Mapping relations between the standard modeling commands set and the native modeling commands set of commercial CAD systems are defined.

• International Journal of CAD/CAM
• /
• v.2 no.1
• /
• pp.13-21
• /
• 2002

It is not possible to exchange parametric information of CAD models based on the current version of STEP. The design intent can be lost during the STEP transfer of CAD models. The Parametrics Group of ISO/TC184/SC4 has proposed the SMCH schema, which includes constructs for exchange of parametric information. This paper proposes a macro-parametric approach that is intended to provide capabilities to transfer parametric information including design intents. In this approach, CAD models are exchanged in the form of macro files. The macro file contains the history of user commands, which are used in the modeling phase. To exchange CAD models using the macro-parametric approach, the modeling commands of several commercial CAD systems are analyzed. Those commands are classified and a set of standard modeling commands has been defined. Mapping relations between the standard modeling commands and the native modeling commands of commercial CAD systems are defined. The scope of the current version is limited to parts modeling, not assemblies.

• Journal of Industrial Technology
• /
• v.24 no.A
• /
• pp.205-214
• /
• 2004

Static reliability models are introduced to analyze the armor stability of rubble-mound breakwaters. Contrasted to the deterministic model, reliability models can estimate the probability of failure directly and calculate the influence of each design variables quantitatively. Thus, it can be possible to design armor units of the rubble-mound breakwaters rationally. In this study FMA(First-order Mean-value Approach), FDA(First-order Design-value Approach) and AFDA(Approximate Full Distribution Approach) of Level II approach of static reliability methods are used to analyze the armor stability of rubble mound breakwaters. The limitations and applications of each approach are studied straight-forwardly.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 1999.10a
• /
• pp.452-457
• /
• 1999

The recent control system has been changed into the type of PLC(Programmable Logic Controller) control. Up to now, systematic approach of PLC programming or control logic design is not suggested. In this study, the design process of the control logic is systematized and concrete process in each step is suggested. This systematized approach lead developer to be convenient to implement control system. When some error is occurred in the system, this approach enable the developer to analyze the reason of error rapidly and the system is amended according to systematic information of the analysis. The example of control system implementation following this approach is introduced.

• Journal of Institute of Control, Robotics and Systems
• /
• v.7 no.12
• /
• pp.1031-1035
• /
• 2001

In this paper, a robust recursive control approach for nonlinear system, which is based on Lyapunov stability, is proposed. The proposed method can apply to extended systems including cascaded systems and the stability is guaranteed in the sense of Lyapunov. The recursive design procedure so called “robust recursive control approach” is used to find a stabilizing robust controller and simultaneously estimate the uncertainty parameters. First, a nonlinear model with uncertainties whose bounds are unknown is derived. Then, unknown bounds of uncertainties are estimated. By using these estimates, the stabilizing robust controller is updated at each step. This approach is applied to the pitch autopilot design of a nonlinear missile system and simulation results indicate good performance.