• International Journal of Precision Engineering and Manufacturing
• /
• v.1 no.2
• /
• pp.67-75
• /
• 2000

virtual computer numerical control(VCNC) arises from the concept that one can experience pseudo-real machining with a computer-numerically-controlled(CNC) machine before actually cutting an object. To achieve accurate VCNC, it is important to determine abnormal behavior, such as chatter, before cutting. Detecting chatter requires an understanding of the dynamic cutting force model. In general, the cutting process is a closed loop system the consists of structural and cutting dynamic. Machining instability, namely chatter, results from the interaction between these two dynamics. Several previous reports have predicted stability for a single path, using a simple cutting force model without run out and penetration effects. This study considers both tool run out and penetration effects, using experimental modal analysis, to obtain predictions that are more accurate. The machining stability during a corner cut, which is a typical transient cut, was assessed from an evaluation of the cutting configurations at the corner.

• Journal of the Korean Society for Precision Engineering
• /
• v.6 no.4
• /
• pp.126-135
• /
• 1989

In this study, in order to perform dynamic design of machine tools reasonably and effectively, a method was formulated to be applicable to the structures connected by joints having elasticity and damping by using substructure synthesis method. And to analyze chatter-free performance, a 3 dimensional cutting dynamics theory was used. Computer program package for the dynamic design of machine tools was developed by combining those and spplied to improvement of performance of NC lathe. Also, the optimization in the structural modifications of machine tool substructure was studied by evaluating the effects of the substructural modifications on total system performance.

• Journal of Preventive Medicine and Public Health
• /
• v.20 no.1 s.21
• /
• pp.40-48
• /
• 1987

In this paper strategic planning is applied for effective management to improve hospital income. Though community hospital has been set up for improving the health status of community, it must be trying to increase income for continuing with referral hospital in the community. The most useful tool of management to do this purpose is thought of strategic planning. Therefore this paper developed strategic planning a typical community hospital, which for it presenting the strategic planning process and developing the simulation model for evaluation of strategic alternatives. In the result it is represented that admission rate is the most sensitive to hospital operating income among the important variables in the model. And simulation by changing the parameter could estimate the yearly hospital income in the response of alternatives. This strategic planning simulation model has had constraints as number of date but also significance such as evaluating the alternatives by quantitative model and at first applying the hospital in our country.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2004.09a
• /
• pp.307-311
• /
• 2004

The unsaturated zone is a significant pathway of the surface contaminant movement and is a highly heterogeneous medium. Therefore, there are limitations in applying conventional convection-dispersion equation(CDE). Artificial neural network(ANN) is considered to be a versatile tool for approximating complex functions. For evaluating the applicability of ANN, numerical tests using ANN were conducted with training set generated by HYDRUS-2D which is based on CDE. The results represent that ANN can estimate the solute transport and the choice of network parameters and generation of training set patterns are important for efficient estimation.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2004.10a
• /
• pp.156-161
• /
• 2004

The application of solar energy, in the field of alternative energy, was on the increase tendency. In the case of advanced nations, through continuous R&D, solar hot water heater with high efficiency has been used for the house and the industrial process on business, advanced nations were reached up the experimental stage of solar generation system. But, the actual circumstance of the domestic has been not accomplished the popularization of solar hot water heater and the settlement of it which is the fundamental stage of the solar energy usage. This trouble, the domestic was flooded with small enterprise for producing solar hot water heater, was caused by the popularization and the production without verification of performance. To supply the monitoring program for evaluating solar hot water heater, this research was purpose to improve the technical development of the enterprise for producing solar-heat hot-water-boiler and served as an aid for the enlargement and the popularization on solar energy.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.13 no.1
• /
• pp.28-34
• /
• 2004

In this study, new way of evaluating manufacturing cost Is organized and applied. In real manufacturing circumstances, tolerances of parts and assemblies are closely related to the cost. Several researches have been tried to identify the relations and set models. Moreover tolerances have influences on the maintenance of the manufacturing facilities. However Past researches have not considered the processing cost for the failed products. Therefore maintenance costs are represented as stochastic expressions, which include reliability of assembly and facilities. The stochastic nature of the maintenance cost is modeled and solved using Markov chain approach. Results show that this approach gives reliable estimations with remarkable computing time reduction.

• Journal of the Korean Society for information Management
• /
• v.20 no.1
• /
• pp.321-339
• /
• 2003

This article surveyed the current situation of domestic R&D information system and investigated the possibility of knowledge-transformation for KMS. Four major requirements of the transformation were analyzed by applying evaluation index tool which was integrated and refined from the existed indices. and a process-oriented project approach was suggested with some practical implications for development of KMS.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.13 no.2
• /
• pp.9-16
• /
• 2004

Because a generated heat during grinding operation makes a serious deformation on a ground surface as a convex form, a real depth of cut in deformed zone has larger than an ideal depth of cut. Consequently, the ground surface has a geometric error as a concave form after cooling the workpiece. In this study, the force and the geometric error of surface grinding were examined. From evaluating magnitude and mode of the geometric error according to grinding conditions, an optimal grinding condition was proposed to minimize the geometric error. In addiction the relationship between the geometric error and the grinding force was found out. Due to least square regression it was able to predict the geometric error by using the grinding force.

• Journal of Korean Society for Quality Management
• /
• v.27 no.2
• /
• pp.251-262
• /
• 1999

In the automated manufacturing systems, the problem regarding how to make production activities flexible is even more important and critical than that regarding how to product large quantities, and the more flexible, if possible, the manufacturing system is, the more competitiveness and profitable factors it gets. This research, therefore, concentrated on establishing the flexibility and evaluating performance on the manufacturing system, operational flexibility is considered because of enabling the manufacturing system to get both the improvement of production rate and the adaptive ability of environment changes. For it, we used the analytical tool, GSPNs, which is a kind of timed Petri-Nets. GSPNs is competent enough to consider practical situations just like operation priorities, machine failure, randomness, concurrency and so on. Through the GSPNs analysis, it is confirmed that in the manufacturing system with operational flexibility is compatible with the traditional performances such as production rate or mean waiting time.

• Food Science and Biotechnology
• /
• v.18 no.2
• /
• pp.279-293
• /
• 2009

Quantitative risk assessments are related to implementing hazard analysis and critical control points (HACCP) by its potential involvement in identifying critical control points (CCPs), validating critical limits at a CCP, enabling rational designs of new processes, and products to meet required level of safety, and evaluating processing operations for verification procedures. The quantitative risk assessment is becoming a standard research tool which provides useful predictions and analyses on microbial risks and, thus, a valuable aid in implementing a HACCP system. This paper provides a review of microbial modeling in quantitative risk assessments, which can be applied to HACCP systems.