• Journal of Korean Institute of Industrial Engineers
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• v.36 no.4
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• pp.243-247
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• 2010

Every products, which made by mass production, is not identical in their size but have variations in some intervals specified by tolerance dimensions. Tolerances play major role in standardization of part and its quality, and also make a huge impact on manufacturing cost. The optimal condition for tolerances is giving the values as loose as possible for low production cost while satisfying quality specification, which usually demand tight control of tolerances. Tolerance analysis is necessary to get an optimal solution for this conflict situation. This paper have studied tolerance analysis for universal joint assembly of vehicle steering system and tried to find useful results of the study for product design and quality control.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.1
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• pp.92-99
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• 2004

With the advent of computers, CAD systems are widely used for various design practice. Complexity of CAD systems and difficulty of exchanging data among different CAD systems, however, do not allow efficient use as desired. In addition, to follow variety of designers' need, CAD activities should be customized. This article proposed a methodology fer developing an intelligent CAD system and the sate-of-the-art technologies described fur customizing CAD systems using API (Application Programming Interface). A basic platform is proposed and a useful application system is implemented to enable a parametric design by directly inputting numerical values on a CAD model. Based on this application, we developed a system that makes it possible to share part family data between SolidEdge and Pro/Engineer. The proposed concept on intelligent CAD systems facilitates integration of external systems such as CAE tools and promotes the use of CAD for both engineering designers and analysts.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.633-637
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• 1995

Numerical calculation tool for forging of gear-like components based on kinematically admissible velocity fields for upper bound method applicable to various deformation features of workpiece in forging processes were suggested. Each one of them deals with unidirectional flow of metal on dies, such as external involute spur gear, sequare spline, internal serrations. A complex calcuation tool of gear-like component forging process was built up by combining these kinematically velocity fields. In this paper, the workpiece with both external and internal teeth is divided into two parts. The deformation of each part is analyzed simultaneously using numerical calculation tool form combined kinematically admissible velocity field. The experimental set-up was installed in a 200 ton hydraulic press. As a result, each kinematically admissible velocity field could be combined with other and the calculated solution are useful to predict the capacity of forging equipment.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.17 no.1
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• pp.13-22
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• 2014

Esophageal pH monitoring is considered the gold standard for the diagnosis of gastroesophageal reflux disease because of the normal ranges across the pediatric age range. However, this method can only detect acid reflux. Multichannel intraluminal impedance-pH (MII-pH) monitoring has recently been used for the detection of bolus reflux in infants and children. This method allows for the detection of liquid, gas or mixed reflux in addition to acid, weakly acidic or weakly alkaline reflux. MII-pH monitoring can record the direction of flow and the height of reflux, which are useful parameters to identify an association between symptoms and reflux. However, the technique is limited by its high cost and the lack of normative data of MII-pH in the pediatric population. Despite certain limitations, MII-pH monitoring will become more common and gradually replace pH monitoring in the future, because pH monitoring is part of MII-pH.

• Journal of Korean Society of Transportation
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• v.11 no.2
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• pp.63-84
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• 1993

The main purpose of this paper is to develop a route guidance system which is a part of the intelligent vehicle-highway system and to apply to a real world in order to evaluate usefulness of the system. To this end, significant literature review works with regard to vehicle navigation and route guidance systems were conducted and have provided an important information about state-of-the-art systems developed and tested by the advanced countries. A geographic information system, called INTGIS, was used to find the shortest path in a given road network. Three scenarios to find minimum path were simulated and observed : 1) with-constraint on intersections and road segments, 2) without-constraint on intersections and road segments, and 3) via several stops from origin to destination. Based on a series of experiments, the results indicate that the route guidance system developed in this research is very useful to inform drivers on highway and arterial the traffic informations such as congestion and incident.

• Transactions of Materials Processing
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• v.3 no.4
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• pp.454-467
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• 1994

The drawbead restraining forces for the various radius of drawbead and die corner are analyzed by the belt theory, and they are compared with the experimental results. During this procedure, the drawing angles are also varied from $0^{\circ}$ to $60^{\circ}$, and the near part of the drawed die corner are divided into fur steps for the theoretical analysis. The stress distributions through the sheet thickness for these steps are also suggested theoretically. The wide range of experimental data of the drawing forces and strain distributions for the various dimension and blank holding forces are presented. It is concluded that the theoretical assumption for the restraining force analysis is very useful from the comparison with the experimental results.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1998.04a
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• pp.704-709
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• 1998

An automated calibration system of sound level meters was developed and tested. As a standard sound source, the speaker unit(Forstex FE208) cabineted by 440 * 390 * 490 mm$^{3}$(LHW) volume wood box was adopted. Including this source, the driving part was found out to have a good linearity of sound pressure output vs AC input. We use the Hybrid-Bisect, /Newton-Raphson method modified by the linearity as searching algorithm. Personal computer and program do the control, measurements, and calculations and finally do the accumulation of useful data and results. Several trials of automatic calibration using this developed system give reliable results.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.6
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• pp.241-247
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• 1999

This study presents the structural analysis of car a seat frame by the finite element method. The load-deformation characteristics of seat frame are simulated according to the test requirements by FMVSS. Three dimensional modeling technique is applied to the components of the seat frame. The shell, solid , gap and rigid elements are employed to model the car seat frame assembly. Numerical results show that the recliner and kunckle plate are identified as the possible weak part of frame, and the results are well consistent with the experimental static load test. The current analysis model can provide useful informations to design a new car seat and can reduce the overall design cost and time.

• Korean Management Science Review
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• v.12 no.2
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• pp.165-188
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• 1995

The conversion processes from traditional job shops to cellular manufacturing systems can be viewed as an aggregation of cause-and-effect relationships among many strategic, managerial, and technical variables. Therefore, management needs to fully understand these interacting variables and possible relationships between the variables to successfully convert their plants to cellular manufacturing systems. The purpose of this study is to assist such management's needs in part. The objectives of this research are i) investigating contingency variables that may affect the conversion processes and outcomes to cellular manufacturing systems and ii) examining relationships between the variables and the conversion processes and outcomes. In this paper, particularly three categories of variables are examined: product, process routing, and process technology / facilities characteristics. Literature review and the mail survey method are used. The results are compared and synthesized with the findings of previous studies for useful discussions. Some previous arguments and propositions are empirically supported.

• Advances in concrete construction
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• v.1 no.2
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• pp.187-200
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• 2013

The damage level in structures (global scale), elements (intermediate scale) and sections (local scale) can be evaluated using a single parameter called the "Damage Index". Part of the damage attributed to the local scale relates to the damage sustained by the materials of which the section is made. This study investigates the damage of concrete subjected to monotonic compressive loading using four different damage models - one proposed here for the first time and three other well-known models. The analytical results show that the proposed model is promising yet simple and effective for evaluating the damage of concrete. The proposed damage model of concrete with its promising characteristics indicated, appears to be a useful tool in the damage assessment of structures made of concrete.