• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.5A
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• pp.255-266
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• 2012

Main cable of a suspension bridge is the important member which shows the overall structure integrity at bridge completion. Configuration of main cable is a free hanging state at cable erection completion and is different from that at bridge completion supporting the dead loads such as hanger, girder, and so on. Accordingly, the configuration control under cable erection is considerably significant because the configuration at cable erection completion has direct influence on that at bridge completion. That is performed by sag adjustments at center, side span and tension adjustments at anchor span. The former needs the sag sensitivity which represents the control quantity of strand length corresponding to that of sag. The latter requires the tension sensitivity which shows the change of strand tension according to that of strand temperature. In this study, the fundamental equations of cable were derived with the assumption of either catenary or parabola shape, the differential-related equations using chain rule on horizontal tension were drawn from those and finally the estimation methods of the sag / tension sensitivity were proposed from both those. The nonlinear numerical analysis flow charts of sag sensitivity based on the catenary equations were proposed and the sag sensitivities grounded on the differential-related equations were compared with the results using them for various parameters of sag change. Also, considering the combinations of sag change parameters, the calculation method of the final variation for the cable sag was suggested. For the real suspension bridge under construction with PPWS method, the sag/tension sensitivity were estimated considering the construction conditions like the change of PPWS length, PPWS temperature, bridge span, etc.. We hope that this study will be a systematic guideline for the configuration control under main cable erection and improved highly by field verification in the real bridge site.

• Journal of the Korean Society of Propulsion Engineers
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• v.3 no.2
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• pp.82-91
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• 1999

Projectile shapes of the superdetonative ram accelerator have great effects on shock structures, detonation wave formation, and ram acceleration characteristics. In this study, cone-cylinder-cone, a baseline projectile configuration of the superdetonative combustion mode, double-cone configurations and power-law shape, have been numerically investigated to analyze the effect of the front/rear configuration changes, on the flow field around the projectile, detonation wave formation process, and projectile acceleration characteristics. Hence, a ram projectile configuration with conspicuously improved acceleration characteristics has been proposed by adjusting the double cone angle and height. The results provide useful information for the ram accelerator design optimization study.

• The Transactions of the Korea Information Processing Society
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• v.4 no.11
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• pp.2745-2755
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• 1997

Many large-scale enterprises have developed software systems to build management information system for their business. However, it is hard to maintain share ability of data, compatibility of operation methedology, and interoperability among subsystems when the development project progresses since each distributed team prepares a development plan for its subsystem and must have poor communication problem among those teams. We must apply software configuration management to the whole life cycle of the software system in order to solve those Problems. We need a model and a repository in order to execute configuration management on configuration products like document, data, and source code which are generated through the life cycle of software development. In this paper, we suggest a model for configuration change control where cross- referencing among life cycle Phases and data-sharing are highlighted, and define ER model to use IRDS(Information Resource Dictionary system) and IRD schemas.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.1
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• pp.55-63
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• 2016

New materials and shapes for a humidifying element were developed which outperformed the widely used crisscross glass wool Glasdek media design. The new material consists of 50% cellulose and 50% PET. The parallel channel configuration was devised to reduce excessive pressure loss caused by the reduced height (from 7.0 mm to 5.0 mm) of the crisscross configuration. For the same crisscross configuration, the humidification efficiency of the cellulose/PET element was 26% higher than that of the glass wool element. For the same cellulose/PET material, humidification efficiency of the parallel channel configuration was 14% higher than that of the crisscross configuration. As for the pressure drops, the cellulose/PET element was 2-52% higher than those of the glass wool element. For the same cellulose/PET material, the pressure drop of the parallel channel configuration was 14% higher than that of the crisscross configuration. Data were compared against the predictions from existing correlations and those by the proposed model.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.25 no.2
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• pp.63-68
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• 2017

In the present study, a wind tunnel test for a rotor-blade configuration was conducted to investigate a basic aerodynamic performance and a effect of the cross wind. The diameter of the configuration was 1.46 m and the test was carried out for both a clean and a tripped configurations. The boundary layer for the trip configuration was simulated by zig-zag tape and the test performed on constant-velocity and constant-rotational modes. It was shown that the test result for the tripped configuration reduces the maximum power coefficient by 9.4% ~ 12.1% compared to the clean one. Within $5^{\circ}$ of the flow angle, there is no significant loss of power, however, the coefficient is reduced by 5.3% ~ 36.7% in the range of $10^{\circ}{\sim}30^{\circ}$.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.231-232
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• 2016

Configuration Management (CM) is a process of identifying and documenting the characteristics of a Structures, Systems and Components (SSCs), and of ensuring that changes to these characteristics are properly assessed, approved, issued, implemented and verified. There are requirement management, change control, facility configuration information management for CM activities. In order to improve safety of Nuclear Power Plant(NPP), it is necessary to manage change item systematically. Existing CM concept is focused on the NPP in operation. On the other hand, NPP under construction is difficult to efficiently manage the change because of different change process from varoius stake-holders. This research considers method of consolidation change process for NPP to ensure that approved changes are accurately reflected in the design requirements, facility configuration information, and the physical configuration.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.25 no.3
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• pp.115-122
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• 2017

To achieve designed quality and reliability from R&D to force integration, an establishment of precise and distinct specifications and standards are required. However, the recent process of R&D standardization on defense acquisition system, has brought plenty of corrections on specifications and standards that may cause not only difficulties to production line and retardation to the military forces, but also a degradation of provided weapon systems. Therefore, a technical review should be performed by the developer, the producer, and the client, establishing the standard that include mass production requirements as well as clients' requirements. This paper propose a specified solution on process of R&D standardization, by applying a substantial FCA(Functional Configuration Audit) and PCA(Physical Configuration Audit) which implies participation of related agencies. By the improved PCA, 2,023 corrections on 74 types of QAR(Quality Assurance Requirement)s and 12,715 corrections on drawings are identified.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.10
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• pp.2217-2223
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• 2012

As smartphone users are over 20 million, companies, which offer cloud computing services, try to support various mobile devices. If so, users can use the same cloud computing service using mobile devices, as sharing document. When user share the work, there are problem in configuration management, data confidentiality and integrity. In this paper, we propose a method that cloud computing users share document efficiently, edit encrypted docuements, and manage configuration based on homomorphic encryption, which integrity is verifiable.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.9
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• pp.9-15
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• 2005

This paper describes the test carried out on an experimental study of fuselage drag and stability characteristics of a helicopter configuration and the test techniques developed for the testing and the lessons learned in the Agency for Defense Development Low Speed Wind Tunnel(ADD-LSWT). The main objective of this test is to determine the drag and stability characteristics of helicopter configurations according to the various configuration changes. The fuselage model with a highly modular structure is a representation of 1:8 scale of the external contour of the conceptual design helicopter configuration with rotating main rotor hub including blade stubs capable of rotating up to 500 rpm. The test results are compared with the available similar data and fair to good agreement is obtained.

• The Journal of Society for e-Business Studies
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• v.2 no.2
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• pp.1-30
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• 1997

In this research, the concept of CM (configuration management) is introduced for proper applications to the life-cycle product data management. In addition, the activities for CM - CM management and planning, configuration identification, configuration control, configuration status accounting, and configuration verification and audit - are described in detail. For the management of distributed configuration data among governments, prime contractors, and subcontractors, development environments and functions for the configuration management information system (CMIS) are proposed.