• Korean Journal of Construction Engineering and Management
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• v.20 no.6
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• pp.11-22
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• 2019

Current construction project processes pose difficulties for construction management as inefficient communication between project participants seldom accurately reflects the needs of the owner. To solve this problem, lean construction-based Integrated Project Delivery (IPD), which facilitates cooperation and builds trust through the formation of horizontal relationships among participants, is becoming increasingly popular. However, although lean construction-based IPD improves productivity in the construction industry, few studies have focused specifically on developing effective methods that maximize the benefits gained from lean construction-based IPD. This study therefore analyzed success factors for lean construction-based IPD projects by analyzing prior studies to identify factors that support IPD success. Application methods were analyzed and an example of how they are actually used in the field was examined through an in-depth single case analysis. The findings of this research can be applied to support lean construction-based IPD projects in Korea, improving their efficiency and boosting owner satisfaction.

• Design & Manufacturing
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• v.13 no.3
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• pp.35-40
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• 2019

As the consumer market in the cosmetic, vehicle manufacturing and aerospace industries grows, the demand for manufacturing industries using on injection mold technology. Also, such manufacturing technology of metal machining is expensive, and the shape is limited. Cosmetic cushion fact products are divided into outer relevant to the exterior of the product and inner containers containing the actual contents. In the case of the inner container, it needs to be combined with the upper and lower cases. As environmental regulations are strengthened internationally, the use of a large number of component parts can result in significant losses in recycling and economics. Therefore, this study aims to perform injection molding analysis through injection molding simulation to develop a cushion fact container that can be recycled through the unification of products and materials using polypropylene to cope with environmental regulations. In the case of injection molding conditions, Injection Time(sec): 4.5, Cooling Time(sec): 13, Resin Temperature($^{\circ}C$): 240, and Pressure(MPa): 30 were determined. The results of injection molding simulation according to the two design methods were compared with the sync mark which shows the problem of filling and injection molding.

• Journal of Digital Convergence
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• v.17 no.10
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• pp.439-446
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• 2019

Feminism on the theme of gender equality is emerging as an important issue in the overall Korean culture. Feminism is not only a level of claiming or advocating women's rights, but an essential subject of gaze and thought, not a distorted, artificially portrayed image of women distorted or typified in a story created by men in the past It is a film that explores the problem of the individual's life in society fundamentally. Jun Koeun's movie' 'micro-habitat'(2018) 'expresses a feminist theme that shows a strong self - selection and transcendental thinking in male - oriented stereotypes and inequal social structure. The film, which focuses on the public insight into society and the enhancement of the ideal human being from the viewpoint that the public film should lead the educated enlightenment character that raises the broad insight into the world and lead the mature social culture, I think it will play a big role.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.148-148
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• 2018

Land subsidence caused by excessive groundwater pumping is a serious hydro-geological hazard. The spatial variability in land use, unbalanced groundwater extraction and aquifer characteristics are the key factors which make the problem more difficult to monitor using conventional methods. This study uses the European Space Agency (ESA) Sentinel satellites to investigate and monitor land subsidence varying with different land covers and groundwater use in the arid Quetta valley, Pakistan. The Persistent Scattering Differential Interferometry of Synthetic Aperture Radar (PS-DInSAR) method was used to develop 28 subsidence interferograms of the study area for the period between 16 Oct 2014 and 06 Oct 2016 using ESA's Sentinel-1 SAR data. The uncertainty of DInSAR result is first minimized by removing the dynamic effect caused by atmospheric factors and then filtered using the radar Amplitude Dispersion Index (ADI) to select only the stable pixels. Finally the subsidence maps were generated by spatially interpolating the land subsidence at the stable pixels, the comparison of DInSAR subsidence with GPS readings showed an R 2 of 0.94 and mean absolute error of $5.7{\pm}4.1mm$. The subsidence maps were also analysed for the effect of aquifer type and 4 land covers which were derived from Sentienl-2 multispectral images. The analysis show that during the two year period, the study area experienced highly non-linear land subsidence ranging from 10 to 280 mm. The subsidence at different land covers was significantly different from each other except between the urban and barren land. The barren land and seasonally cultivated area show minor to moderate subsidence while the orchard and urban area with high groundwater extraction rate showed excessive amount of land subsidence. Moreover, the land subsidence and groundwater drawdown was found to be linearly proportional to each other.

• Journal of Korea Port Economic Association
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• v.22 no.3
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• pp.23-41
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• 2006

The objective of this study is to discuss damage to cargo caused by shipper's Liability. an analysis of the excepted perils of the carriers and the scope of marine insurance coverage reveals that the excepted perils of the carrier are covered by the most part by marine insurance. however damage to cargo caused by shipper's fault remains uncovered. Damage to cargo by insufficient packing is caused by the cargo owner's error or negligence, thus both the underwriter and the marine carrier are exmpted from responsibility. but a problem aries from the fact that there is no objective standard for full packaging. In order to solve these problems, it is required to specify the method of packaging for certain goods when making an individual agreement, so that the owner can be exmpted from responsibility for packaging conformed to the pertinent article.

• Smart Structures and Systems
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• v.18 no.3
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• pp.569-584
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• 2016

This paper presents a method for stochastic modelling of fatigue crack growth and optimising inspection and maintenance strategy for the structural members of steel bridges. The fatigue crack evolution is considered as a stochastic process with uncertainties, and the Gamma process is adopted to simulate the propagation of fatigue crack in steel bridge members. From the stochastic modelling for fatigue crack growth, the probability of failure caused by fatigue is predicted over the service life of steel bridge members. The remaining fatigue life of steel bridge members is determined by comparing the fatigue crack length with its predetermined threshold. Furthermore, the probability of detection is adopted to consider the uncertainties in detecting fatigue crack by using existing damage detection techniques. A multi-objective optimisation problem is proposed and solved by a genetic algorithm to determine the optimised inspection and maintenance strategy for the fatigue affected steel bridge members. The optimised strategy is achieved by minimizing the life-cycle cost, including the inspection, maintenance and failure costs, and maximizing the service life after necessary intervention. The number of intervention during the service life is also taken into account to investigate the relationship between the service life and the cost for maintenance. The results from numerical examples show that the proposed method can provide a useful approach for cost-effective inspection and maintenance strategy for fatigue affected steel bridges.

• Structural Engineering and Mechanics
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• v.57 no.5
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• pp.837-859
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• 2016

An efficient shear deformation theory is developed for wave propagation analysis of an infinite functionally graded plate in the presence of thermal environments. By dividing the transverse displacement into bending and shear parts, the number of unknowns and governing equations of the present theory is reduced, and hence, makes it simple to use. The thermal effects and temperature-dependent material properties are both taken into account. The temperature field is assumed to be a uniform distribution over the plate surface and varied in the thickness direction only. Material properties are assumed to be temperature-dependent, and graded in the thickness direction according to a simple power law distribution in terms of the volume fractions of the constituents. The governing equations of the wave propagation in the functionally graded plate are derived by employing the Hamilton's principle and the physical neutral surface concept. There is no stretching.bending coupling effect in the neutral surface-based formulation, and consequently, the governing equations and boundary conditions of functionally graded plates based on neutral surface have the simple forms as those of isotropic plates. The analytic dispersion relation of the functionally graded plate is obtained by solving an eigenvalue problem. The effects of the volume fraction distributions and temperature on wave propagation of functionally graded plate are discussed in detail. It can be concluded that the present theory is not only accurate but also simple in predicting the wave propagation characteristics in the functionally graded plate. The results carried out can be used in the ultrasonic inspection techniques and structural health monitoring.

• Journal of the Korea Society for Simulation
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• v.29 no.3
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• pp.19-25
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• 2020

The field farming machine is difficult to develop due to its heavy slopes, tough roads and unformatted cultivation by growing crops. In particular, harvesting is a major problem in rural areas in Republic of Korea where aging is accelerated with work requiring a lot of time and manpower. This study seeks to analyze the dynamic characteristics of hot pepper harvester developed to replace manpower, reduce working hours and mechanize harvesting operations. To analyze the dynamic characteristics of a hot pepper harvester, the dynamic program Recurdyn was used and all analysis were performed as case of an empty vehicle. Based on the results, this study can suggest dynamic safety range of multi-purpose driving platform with hot pepper harvester.

• Journal of the Society of Naval Architects of Korea
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• v.30 no.3
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• pp.29-40
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• 1993

The fundamental characteristics of nonlinear free-surface waves generated by a shallowly submerged 3-dimensional hydrofoil are investigated. The fluid is assumed inviscid, incompressible and its motion irrotational. The surface tension on the free-surface is neglected. The hydrofoil is represented by a horseshoe vortex system whose shape is assumed fixed. Also the strengths of vortices are assumed given. The exact problem for the wave potential due to the horseshoe vortex system is formulated by the variational principle based on the classical Hamilton's principle. The localized finite element method is used in the numerical computations. In order to increase the numerical efficiency, an intermediate nonlinear-to-linear transition buffer subdomain for a smooth matching is introduced between the fully nonlinear computation subdomain and the truncated linear infinite subdomain. Also used is the modal analysis to reduce the computation tome drastically. The effect of inflow velocity, submergence depth of the hydrofoil and the shape of circulation distribution on the wave profiles are thoroughly examined. Especially it was possible to investigate the nonlinear influence of the free vortex on the free vortex. The nonlinear free-surface effect on the induced forces on the hydrofoil is also investigated.

• Korean Journal of Bronchoesophagology
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• v.15 no.1
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• pp.28-34
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• 2009

Background and Objectives: Foreign bodies of upper aerodigestive tract are common problem for primary care physicians. Delayed diagnosis or failure of removal might cause fatal problemsand complications. Therefore proper diagnosis and management is imperative. In this study, we described clinical features of upper aerodigestive tract foreign body, and analyzed efficacy of different management modality. Materials and Methods: 250 cases of foreign bodies in the esophagus and trachea, between Jan. 1998 through Jan. 2009 has been retrospectively analyzed. A total of 24 cases and 226 cases had been found each as airway foreign bodies and esophageal foreign bodies. The clinical features are described and treatment outcomes, prognosis, and rate of complications of each management modality have been compared. Results: In airway foreign bodies, ventilating bronchoscopy yielded better results, 19 success out of 19 trials than fiberoptic bronchoscopy, 3 success out of 5 trials. Hospitalization days after removal of foreign body didn't show difference between two treatment modalities, although patients who had ventilating bronchoscopy had gone through general anesthesia. And there was no complication after removal of foreign body. In esophageal foreign bodies, rigid esophagoscope yielded better results, 99% of successful removal rate, compared to the EGD, only 78% of successful removal rate. There was no difference of hospitalization days between two modalities. And complication rate was even low in patients who had done rigid esophagoscopic foreign body removal. Conclusion: In upper aerodigestivetract foreign body. Rapid diagnosis and successful foreign body removal is important. Removal by rigid scope(ventilating bronchoscope, rigid esophagoscope) revealed less failure in both airway and esophageal foreign bodies.