• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.5
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• pp.1392-1400
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• 1996

The need of companies shorten the design-to-manufacturing process for new products with improved quality in cost effective manner places increasing demends on engineers to simulate the performance characteristics of a design before it is built of a prototype is developed. For theses demands CAE(Computer-Aided Engineering) offers engineers not only giving confidence of their design but also eliminating potential errors due totesting prototypes in small numbers. This paper present the method to predict the fatigue life using dynamics simulation and FEA(Finite Element Analysis) for construciton equipment in the computer before building prototype. The dynamicsimulatio is to get the load-time history corresponding to the maneuvering and driving of the construction equipment. The FEA is to build a model of the structure and then analyse to define the local stress response to applied loadings using linear static analysis.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.19 no.6
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• pp.889-894
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• 2010

Conventional shrink-fit tool holders have positive features, such as high accuracy, high strength, high stiffness and low sensitivity to centrifugal forces, but they require heavy investments for heating and cooling equipment. Generally the heating equipment has to heat the tool holder up to $200{\sim}300^{\circ}C$ for tool changes. This paper introduces a novel shrink-fit tool holder that is able to unclamp a tool at $40{\sim}50^{\circ}C$. This feature makes it possible to switch between the clamped and unclamped states by using a simple device, which has lower power, smaller size and lower cost than the heating equipment of the conventional shrink-fit tool holders. The proposed shrink-fit tool holder is able to expand its tool hole by using the shape memory alloys which are integrated in the tool holder body. Performances of the SMA shrink-fit tool holder were evaluated experimentally. The experimental results confirm that the proposed tool holder is feasible in aspects of clamping/unclamping operations, clamping force and repeatability of tool setup.

• Proceedings of the Membrane Society of Korea Conference
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• 1996.06a
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• pp.121-147
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• 1996

Since 1980, the water quality of ultra-pure water has been rapidly improved, and presently ultra-pore water producing equipment for 64Mbit is in operation. Table 1 shows the degree of integration of DRM and required water quality exlmple. The requirements of the ultra-pure water for 64Mbit are resistivity: 18.2 MQ/cm or higher, number of particulates: 1 pc/ml or less (0.05 $\mu$m or larger). bacteria count: 0.1 pc/l or less. TOC (Total Organic Carbon, index of organic snbstance) : 1ppb or less, dissolved oxygen: 5ppb or less, silica: 0.5ppb or less, heavy metal ions: 5ppb or less. The effect of metals on the silicon wafer has been well known, and recently it has been reported that the existence of organic substance in ultra-pure water is closely related to the device defect, drawing attention. It is reported that if organic substance sticks to the natural oxidation film, the oxide film remaims on the organic substance attachment in the hydrofluoric acid treatment (removal of natural oxidation film). The organic substance forms film on the silicon wafer, and harmful elements such as metals and N.P.S., components contained in the organic substance and the bad effect due to the generatinn of silicon carbide cannot be forgotten. In order to remove various impurities in raw water, many technological develoments (membrane, ion exchange, TOC removal, piping material, microanalysis, etc.) have been made with ultra-pure water producing equipment and put to practical use. In this paper, technologies put to practical use in recent ultra-pure vater producing equimeut are introduced.

• Journal of the Society of Naval Architects of Korea
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• v.42 no.5 s.143
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• pp.499-505
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• 2005

Underwater explosion shock response analysis of a nonlinear double resiliently mounted equipment on a MIL-S-901D Large floating Shock Platform(LFSP) was carried out using LS-DYNA3D/USA. As a nonlinear double resiliently mounted equipment, real main engine module of naval ship was considered, where the engine, bearing, and base frame including sound enclosure were treated as rigid bodies with six degrees of freedom. The nonlinear effects of resilient mounts on its shock response characteristics were examined, and the usefulness of our suggested method was also confirmed comparing with calculation results by the equipment maker.

• Korean Journal of Construction Engineering and Management
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• v.13 no.4
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• pp.100-109
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• 2012

Large road construction projects are typically partitioned into sections that are then contracted individually to contractors. Each section requires using similar heavy equipment including excavators, dump trucks and pavers, which constitute the highest cost. Normally the equipment is not shared between them, as each contractor wishes to have their equipment readily available. However, such practices result in very low utilization of these equipment. The goal of this research is to develop a programmatic resource sharing system in which contractors can share equipment depending on the changing needs of a multi-sectioned road project. This paper introduces the results of a survey performed to investigate how contractors currently manage the supply and demand of equipment and the equipment that are practical for sharing across a project. More importantly, the paper describes a set of metrics (DPR, nDPR, SDI) needed to quantify the amount of supply/demand variance occurring in each section. The metrics were used on an actual road construction project, and the results show that each section suffers from an imbalance between its monthly planned and actual utilization of equipment. The results also indicate that the sharing of the equipment can lead to potentially large savings as equipment requirements can be met within a project as to short leasing from outside vendors.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.911-916
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• 1991

Spent nuclear fuel is highly radioactive and requires remote operation due to radiation exposure. Motors which have been used in the highly radioactive environments are a DC type because of their easy implementation on control system. However there are some problems such as mechanical maintenance of brush and commutator, high cost, and heavy material control. AC servo motors are applied and tested on fuzzy and conventional control algorithms. Fuzzy logic controls of AC servo give adequate control accuracy and power for spent fuel handling in radioactive environments.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1999.10c
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• pp.569-574
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• 1999

In Soft ground of south-western coast of our country necessity of marine indutrial complex and container facility has been remarkable. Site construction for habor facility is one of the most urgent problems. Consolidation of dredged fill has become important task. In addition, volume change of dredged fill should be examined carefully. This study dealt with consolidation of dredged fill by PCDDF and in order to secure trafficability of heavy equipment for surface treatment should be studied.

• Proceedings of the Korea Information Processing Society Conference
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• 2018.10a
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• pp.981-983
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• 2018

건설 중장비용 멀티미디어 시스템을 위한 스마트 제어기술은 고객의 스마트폰을 이용하여 오디오 업그레이드 및 스마트 음원 재생, 오디오의 액정 표시 장치 및 제어 판넬의 기능을 수행한다.

• Journal of Aerospace System Engineering
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• v.15 no.6
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• pp.66-71
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• 2021

With the exception of some large domestic airlines with adequate maintenance capability, most low-cost and small airlines do not have the facilities, equipment/tools, or manpower to perform periodic inspections over "C check." They are repaired according to maintenance programs specified by manufacturers. The outsourcing (domestic or overseas) of maintenance contracts is thus crucial to achieve good quality service at low cost, and these contracts therefore need to be signed with a full understanding of what is to be expected. This study aims to determine the requirements to be considered prior to finalizing such contracts.

• Journal of Industrial Convergence
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• v.7 no.1
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• pp.33-43
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• 2009

The purpose of this study was to analysis to jobs inducing the Musculoskeletal Disorders(MD) and improve the working environment. The case study was conducted at S company where makes radiator case of heavy profile equipment. Most of works are plating and welding. Bending and welding are works which induce MD. The adjustable workstation and fatigue prevention mat were recommended for the welding and bending. A standing posture was recommended for the welding.