• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.4
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• pp.1-6
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• 2016

As manufacturing industries become globalized, product design affects every area of organization. The design sets the goals for a number of different departments, so if it fails to effectively communicate these goals, the entire organization is less efficient. In addition, To communicate clearly, the design must represent a product that meets its technical specification. GD&T (Geometric Dimensioning and Tolerancing) is one of the most important factors, which has an effect on efficiency of manufacture system, in designing products. However, most of designers in different industries are prone to ignore the importance of GD&T. To analyse the importance of GD&T compliance with international standards for design drawing, a comparison analysis of the difference between two methods, composite profile control and multiple single segment profile control, is performed on three different cases and suggests how it used to be more suitable. Composite profile tolerance is specified by a dual feature control frame that has one profile symbol specified with two lines of tolerance information. Whereas a multiple single segment profile control is when two or more single segment profile callouts are used to define the location and/or orientation and/or size and/or form of a part feature. In this study, the following results will be provided : a clear definition and an obvious difference of the tolerance zone, datums and datums sequence and minimization of tolerances. On this study, composite profile tolerance and multiple single segment profile tolerance were discussed. Next steps of research will consist on reaching more accurate results for profile control. Further research will be focused on dealing with the remaining 14 symbols of GD&T.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.2
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• pp.94-102
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• 2020

Precast concrete segment arch system has an economic and construct ability that combined with advantage of precast concrete and arch behavior. A precast concrete segment arch system with outrigger is consisted of segmented precast panels, a steel outrigger rib, and V-strip to connect precast panels with a steel outrigger rib and cast-in-place anchors in precast panels to connect V-strip should have sufficient pull-out capacity to form its arch shape by site lifting for assembled precast panels and outriggers. However, it is difficult to secure its embedment depth due to the relatively shallow thickness of precast panel. It can be also occurred that flexure deformation of precast panels caused by its pull-out behaviors. In this study, pull-out capacity of cast-in-place anchor was examined for construction of precast concrete segment arch system with outriggers. Therefore, a total of 24 precast panel specimens were fabricated to examine pull-out capacities of cast-in-place anchor in precast panels, and installation depth of anchors, diameter of anchors and wire mesh effects for the precast panel were examined. From this pull-out tests, its pull-out capacities and failure modes were evaluated and the type of the cast-in-place anchor applicable to the precast concrete segment panel arch system with outriggers was determined from comparison of the design specification values.

• 시스템엔지니어링워크숍
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• s.6
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• pp.126-129
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• 2005

Systems engineering requirement verification model developmetn for High Speed Railway systems in progress is a national large system development program that is not only large-size and complex but also multi-disciplinary in nature. For the High Speed Railway TEP development, verification requirements that could verify system function, performance, and constraint, should be derived from SSS(system Segment specification). Hereafter, this could be referred to as verification requirements. System engineering process establishes traceability between verification requirements and system requirements. These tasks could be accomplished by the schema. using computer-aided Systems Engineering tool(CORE), High Speed Railway program can become a database and other system related to High Speed Railway program will be developed effectively and efficiently.

• Journal of the Korean Society of Systems Engineering
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• v.2 no.2
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• pp.33-38
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• 2006

It is well known that efficient management and thorough implementation of stakeholder requirements is vital for a successful development of a large-scale and complex system. Equally important is to make sure that all the requirements be correctly realized in the developed system. For the purpose, verification requirements are derived with traceability from the system requirements. This paper discusses a step by step process for constructing the requirements verification model which includes : 1) the schema modeling both requirements and their traceability; 2) the template documenting the verification requirements; 3) the verification model constructed from the schema; and 4) the test and evaluation plan that can be printed automatically.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.653-656
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• 2004

This paper outlines the three main fieldbus type standards: Foundation Fieldbus; WorldFIP; and the Profibus, each of which have great advantages over traditional instrumentation networking technology. The paper shows, using their specification, how they improve traditional control and data acquisition methods. By analysing the main robust, how the can be used to distribute data around the control system, provided increased diagnostic information, are easy to implement, fault confinement, and move simple control operations from the main controller to the local environment. This will help to segment industrial plants into zones which can control themselves. The main control will then be responsibility high-level control. and interzone communications.

• Aerospace Engineering and Technology
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• v.8 no.1
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• pp.187-196
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• 2009

Synthetic Aperture Radar(SAR) satellite system for broad-area imaging has RF systems including SAR radiating a high power, data link system transmitting the acquired image data from the SAR, TC&R(Telemetry, Command, and Ranging) to communicate with a ground segment to control a satellite. Each system transmits RF signal having various frequencies and radiates a high power, RS(Radiated Susceptibility) specification should be verified at an electronic unit mounted in satellite. RF interference can be happened because of non-linearity of a RF system. Therefore, we manufactured a structure model installed antennas which have a similar pattern with a real antenna, the effect by RF interference is analyzed and verified.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.12B
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• pp.1435-1443
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• 2009

In this paper, an energy harvesting sensor network system is modeled and simulated by using the DEVS (Discrete Event System Specification) formalism. The system is composed of a sink (master) node, which is battery or mains powered, and a set of sensor (slave) nodes, each of which harvests ambient energy and converts it into electrical energy. For simulation, (i) the behavior of energy harvesting and storing circuits of the slave node is partitioned into a set of piecewise continuous segments and then each segment is represented as a discrete state; (ii) the interaction among the master node and components of the slave node is investigated preciously; and (iii) the investigated result is modeled and simulated by using the DEVS formalism.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.12
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• pp.66-72
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• 2011

In Japan, the specification for digital terrestrial television broadcasting systems has been approved for employing a transmission scheme for ISDB-T, which can accommodate HDTV service and portable mobile reception by adapting segmentation of frequency. In this paper, we have developed 3.5 inch mobile TV according to One-Seg system and presented the results of our development. In addition, we introduce two diversity schemes to compensate the defect that signal is interrupted when the portable TV is moving fast. In order to achieve a reliable communication in One-Seg system, we introduce STD(space time diversity) which uses more than 2 antennas at TX and cooperative reception diversity which utilizes signal-exchanging between different mobile terminals. And, its performance enhancements to reception reliability of previous system are evaluated by computer simulations.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3A
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• pp.383-390
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• 2008

A Precast Prefabricated Bridge Column using steel tube and prestressing bar was proposed for the application of precast method on substructure. A column specimen designed by the proposed bridge column system was made and performed a quasi-static test. The failure mode appeared to be a flexural failure and there is no damage on column segment connection. And it is good use of the self-centering ability by prestressing force. Test results showed that a column specimen satisfy the earthquake specification, and the structural stability was verified. Nonlinear finite element analysis was performed and compared with the test results. Force-displacement relation and location of crack from the analysis results were compared with the test results and it agreed well. The quantitative analysis was also performed by a parametric study using this modeling technique.