• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.8
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• pp.667-673
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• 2014

In a smart shipyard area, it is possible to integrate a variety of ship modules from separate sites into a final ship construction by using mobile applications. In this paper, we proposed the LTE femtocell network configuration which is applicable to sub shipyard, the traffic exchange method with shipyard headquarter and offload method to separate the general traffic. We defined the mode change in a femtocell gateway for supporting offload for general traffic between the main server in shipyard headquarter and sub shipyard, the offload data managements and message definition. We check the transmitted/received message flow in the wireless link, and consider the performance of the proposed method using state the transition diagram. It is expected that our results can improve the productivity within a smart shipyard by mobile communications and LTE femtocell network.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.4
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• pp.1683-1691
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• 2013

Concrete surface grinding is frequently used for flatness of concrete surface, concrete pavement rehabilitation, and adhesiveness in pavement construction. The procedure is, however, labor intensive and has a hazardous work condition. Also, the productivity and the quality of concrete surface grinding highly depend on the skills of worker. Thus, the development of remote controlled concrete surface grinding equipment is necessary to prevent the environmental pollution and to protect the workers from hazardous work condition. However, it is difficult to evaluate the grinded surface objectively in a remote controlled system. Also, The machine vision system developed in this study takes the images of grinded surface with the network camera for image processing. Then, by representing the quality test results to the integrated program of the remote control station, the quality control system is constructed. The machine vision algorithm means the image processing algorithm of grinded concrete surface and this paper presents the objective quality control standard of grinded concrete surface through the application of the suggested algorithm.

• Explosives and Blasting
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• v.33 no.3
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• pp.14-20
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• 2015

Tunnel blasting that plays the most important role in the construction of a drill & blast tunnel, shows a big difference in operation time according to various factors such as rock mass quality, tunnel dimension, machine performance, and the skill level of tunnel crews. This paper analyzes the differences between the time calculated by the standard of estimate and actual operation time based upon field investigations on blasting operation time in three tunnels of Korea. The result shows that actual blasting time is generally about 8%~16% less than the standard of estimate in cases that normal operations are performed. If the time delayed by unforeseen situations is included, however, it is presumed that the number of cases that actual operation time exceeds the standard of estimate are considerable. This study aims to help make a judgement over the appropriacy of the standard of estimate through continuous investigations on actual operation time, as well as improve the productivity of tunnel excavation.

• IE interfaces
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• v.21 no.3
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• pp.322-332
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• 2008

Digital Virtual Manufacturing is a technology to facilitate effective product developments and agile productions by digital model representing the physical and logical schema and the behavior of real manufacturing system, and it includes product, resources, processes and plant. For successful applications of this technology, a digital virtual factory as a well-designed and integrated environment is essential. In this research, we constructed a sophisticated digital virtual factory of a Korean automotive company's press shop. For efficient constructions of a digital virtual factory useful to kinematic simulations and visualizations, we analyzed entire business process and detailed activities of press engineering. Also, we evaluated geometries, structures, characteristics and motions of a plant and machines in press shop. The geometric model and related data of a virtual press shop are built and managed by a modeling standard defined in this paper. The virtual manufacturing simulation of press machines is conducted to evaluate kinematic motions, cycle time and locations of components using geometric models and related data. It's for interference checks and productivity improvements. We expect that this virtual press shop helps us to achieve great savings in time and cost in many manufacturing preparation activities in the new car development process of automotive companies.

• The Journal of the Korea Contents Association
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• v.6 no.2
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• pp.75-83
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• 2006

The Aircraft Development Department operated a Technical Document Management System that was effectively managed using a database management system for the management of the technical information created by a research and development phase of an aircraft and managed a technical information of a research and development varied by the project on a lot of the aircraft development program. While managing the user management and technical information project, it caused some problems on the workflow of the Work Memo and a search of some technical information, etc. As result, we developed the web-based Integrated Technical Information System(ITIS) which be able to totally manage the Technical Document Management System varied by program. According to the construction and operation of this system, we can access by program using user account and privilege and dramatically increased the productivity of a research and development because of performing the workflow of the Work Memo and some search of technical information by the integrated screen of the ITIS.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2002.11a
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• pp.155-159
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• 2002

Wire ropes are used in a myriad of various industrial applications such as elevator, mine hoist, construction machinery, lift, and suspension bridge. Especially, wire rope of crane is important component to container transfer. If it happens wire rope failures in operating, it may lead to safety accident, economic power loss by productivity decline, competitive power decline of container terminal and so on. To solve this problem, we developed wire rope fault detecting system as a portable instrument, and this system is consisted of 3 parts that fault detecting part using hall sensor, permanent magnets and analog unit, and digital signal processing part using data acquisition card, monitoring part using wavelet transform, denoising method. In this paper, a wire rope is scanned by this system after makes several broken parts on the surface of wire rope artificially. All detected signal has external noise or disturbance according to circumstances. So, we applied to discrete wavelet transform to extract a signal from noisy data that was used filter. In practical applications of denoising, it is shown that wavelet pursue it with little information loss and smooth signal display. It is verified that the detecting system by denoising has good efficiency for inspecting faults of wire ropes in service. As a result, by developing this system, container terminal could reduce expense because of extension of wire ropes exchange period and could competitive power. Also, this system is possible to apply in several fields like that elevator, lift and so on.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.2
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• pp.250-263
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• 2001

The up and down speed of heddle frames that produce woven cloth by insertion of weft yarns between warp yarns has been increased recently much for productivity improvement, which induces higher inertial stresses and vibrations in the heddle frame. the heddle frame is required to reduce its mass because the heddle frame contributes the major portion of the stresses in the heddle frames during accelerating and decelerating. Conventional aluminum heddle frames have fatigue life of around 5 months at 550rpm due to their low fatigue flexural strength as well as low bending stiffness. In this work, since carbon/epoxy composite materials have high specific fatigue strength(S/p), high specific modulus(E/p), high damping capacity and sandwich construction results in lower deflections and higher buckling resistance, the sandwich structure composed of carbon/epoxy composite skins and polyurethane foam were employed for the high-speed heddle frame. The design map for the sandwich beams was accomplished to determine the optimum thickness and the stacking sequences for the heddle frames. Also the effects of the number of ribs on the stress of the heddle frame were investigated by FEM analyses. Finally, the high-speed heddle frames were manufactured with sandwich structures and the static and dynamic properties of the aluminum and the composite heddle frames were tested and compared with each other.

• The KIPS Transactions:PartD
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• v.10D no.1
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• pp.101-108
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• 2003

Construction of automated terminal it urgently demanded to gain the foundation of hub-port in north east Asia. Therefore we suggest an adequate operating system layout of automated terminal in Korea. In this paper the aim of automated terminal operating system is satisfied. four basic models are divided according to moving course of export and import cargo of each automated equipments, several input data are changed and analyzed dynamically by Trial and Error method, and then an optimized operating system model is selected, and designed for yard operating system layout on the basis of the selected model. Particularly, the productivity of automated port is up to the kind of automated equipments. However, because expense and present work process must be considered actually. In order to prevent confusion of the work, the method to optimize the present work and substitute prevent equipments and automated equipments was designed. It is a premise that ail the yard equipments described in this paper must be automatic except quay crane.

• Journal of KIISE:Computing Practices and Letters
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• v.7 no.1
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• pp.38-47
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• 2001

PDM is an integrated solution for managing various kinds of document and information for a whole life~cycle of product management. PDM system spans a huge and complex area and requires so many efforts and budgets for development. A framework has been considered a promising way to improve productivity by reusing the software architecture, not just one part of the design or just source code. This was the reaSon why we developed PDM (Product Data Management) framework. Framework can reduce the time and efforts to develop a new PDM application. However, it also requires supporting environment since a framework is a big set of classes where their interactions are so complex. With this supporting environment, it is easy to understand the framework at a glance and easy to identify what hot spots to be refined to meet new requirements. In this paper, a new framework-supporting reuse environment based on the meta-repository was constructed for easy and convenient reuse.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.989-992
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• 2008

In this paper, we are presenting a case that integrates ultra high strength concrete(150MPa) with surface-exposed concrete. Ahead of the field application, we carried out laboratory experiment and B/P Test for a basic property of concrete(slump flow, air content, 50cm flow time, elapse time change and compression strength) and productivity. The next, we conducted Mock-up Test using simulation specimen to evaluate infilling, surface-finishing and hydration heat of concrete. We had satisfactory results for a basic property and hydration heat of concrete. However at the time of field application, it was occurred rupture of formwork because of high lateral pressure of concrete, and then formwork was reinforced and case-in-place time was adjusted. And regardless of low and high frequency vibration, it occurred to surface-pockmark. In case that applies ultra high strength concrete to surface-exposed concrete, we estimate that it is important of systematic management and improvement of construction.