• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.2
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• pp.101-105
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• 2016

The basic characteristics of glass are highly fragile and brittle consequences the ultimate purpose of glass manufacturing is to make a transparent glass with complex shape. In order to solve this problem, mechanical properties of glass can be increased by crystallization of its amorphous glass. However, glass-ceramics has become opaque through crystallization process due to the distracted interface of glass by precipitated particles. This study has been investigated thermal processing conditions of LAS transparent glass-ceramic by using DTA (differential thermal analysis), in order to control size of precipitated particle and then fabricate transparent glass-ceramic. DTA indicated that crystallization peak area was declined with increased nucleation temperature. Subsequently, we have been established optimum temperature for crystallization depending on the nucleation temperature. The transmission and thermal expansion were measured after crystallization, and the size of precipitated particle was identified in range of 20~100 nm by FE-SEM. In addition, by setting the optimized crystallization condition, with high transmission and low thermal expansion glass was synthesized through this experiment.

• Journal of the Korea Concrete Institute
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• v.13 no.3
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• pp.228-236
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• 2001

Even though numerous researches have been performed for the prediction of thermal stresses in mass concrete structures by both analytical and experimental means, the limitations exist for both approaches. In analytical approach, the fundamental limitation is derived from the difficulty of predicting concrete properties such as modulus of elasticity, coefficient of thermal expansion, etc.. In experimental approach, there are many uncertainties related to in-situ conditions, because a majority of researches have focused on measuring thermal stresses in actual and simulated structures. In this research, an experimental device measuring thermal stresses directly in a laboratory setting is developed. The equipment is located in a temperature chamber that follows the temperature history previously obtained from temperature distribution analysis. Thermal strains are measured continuously by a strain gauge in the device and the corresponding thermal stresses are calculated simply by force equilibrium condition. For the verification of the developed device, a traditional experiment measuring thermal strains from embedded strain gauges is performed simultaneously. The results show that the thermal strain values measured by the newly developed device agree well with the results from the benchmark experiment.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.2
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• pp.70-77
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• 2012

The Ladle Furnace Slag, about 20% of the electric arc furnace slag, has high content of free CaO and free MgO, which generates the expansion collapse by hydration reaction. Although many researchers have been endeavoring to recycle the EAF reducing slag in construction fields, there is not found the effective recycling method up to now. However, the LFS(Ladle Furnace Slag) contains mineral composition of the system of calcium aluminate with high-reactivity. Therefore, it is possible to developed the quick setting property and the high strength at the early age by the rapid cooling. This study aimed to check the reactive minerals and predict the reactivity with water on the LFS discharged from different steel product plants. The test results show that many types of LFS has hydration reactivity and can use in construction field as a inorganic binder with the rapid setting property.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2006.05a
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• pp.95-108
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• 2006

Because of rapid expansion of third party logistics, fierce competition in the transportation industry, and the diversification and globalization of transportation channels, an effective transportation planning by means of multimodal transport is badly needed. Accordingly, this study aims to suggest an optimal transport algorithm for the multimodal transport in the international logistics. Cargoes and stopovers can be changed numerously according to the change of transportation modes, thus being a NP-hard problem. As a solution for this problem, first of all, we have applied a pruning algorithm to simplify it, suggesting a heuristic algorithm for constrained shortest path problem to find out a feasible area with an effective time range and effective cost range, which has been applied to the Label Setting Algorithm, consequently leading to multiple Pareto optimal solutions. Also, in order to test the efficiency of the algorithm for constrained shortest path problem, this paper has applied it to the actual transportation path from Busan port of Korea to Rotterdam port of Netherlands.

• The Journal of Sustainable Design and Educational Environment Research
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• v.13 no.1
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• pp.15-23
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• 2014

With introduction of amended educational curriculum in 2007, optimizing project of educational environment to accomplish its purposes and goals includes expanding educational facilities and supplying eco-friendly school facilities. However, while the focus of optimizing project of educational environment is quality improvement of educational facilities, aging of these facilities built at th times of quantitative expansion and its management become serious problems. Higher concerns on studies and jobs on management of building caused by serious aging of facilities, management cost of building becomes a very crucial issue. Therefore, this study aims to analyze environment improvement budget of school facilities through building and using data warehouse, by investigating and analyzing the current status of environment improvement budget of school facilities and its cost through questionnaire and interview surveys on officers who are in charge of environment improvement budget of school facilities in educational administrations. This study thus analyzed environment improving budget of school facilities by using data warehouse technology collecting related data to the topic and setting levels by region, school class, establishment year, school facility types and others.

• Journal of the Korea Furniture Society
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• v.20 no.1
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• pp.82-94
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• 2009

In this study, I suggest dyed-Glued laminated woods by using birch woods which are relatively cheaper than others. Since the dyed-Glued laminated woods which have the various colors to satisfy people's tastes and the dignified grains in the old woods enable us to product freely, these can provide us with stability of supply through replacing rare materials. The making wooden furniture designed with dyed-Glued laminated woods has these following characteristics. (1) This method which uses various colored woods can fulfill consumers' tastes through dyeing wooden plates, instead of using domestic woods which have limited colors-white, yellow and black. (2) Gathering wooden plates made by setting them into various frames enables us to get in large quantities of the materials with good grains, which we can only take from old woods. (3) Producing culture products using various colors and grains has enabled us to satisfy consumers and to create pro-environmental pieces. In conclusion, this study can be an alternative idea to forest resources which have been decreasing, and be an application method of using cheaper birch woods as well. Gathering and dyeing wooden plates might bring about the economic effect and be of much help to the expansion as furniture materials as well as interior ones.

• Journal of Korean society of Dental Hygiene
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• v.19 no.6
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• pp.907-918
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• 2019

Objectives: This qualitative research was conducted to clearly find and clinically understand dental hygienists' work experience in order to lay the legal foundation for their work range and safe execution. Methods: From March 1 to April 30, 2019, seven study participants were selected and participated in-depth interviews. Phenomenological research methodology was applied for intensive analysis. Results: They performed jobs that required no professionalism, such as dental assistance, except for scaling. Dental hygienists, nurses' aids, and dental technicians performed the same jobs regardless of difficulty level and legal work range. Dental hygienists failed to accurately recognize their legal work range. Since there was the wide gap between their legal work range and actual work range, it was necessary to expand the work range in line with actual conditions. Conclusions: Given the results, it is necessary to conduct in-depth discussions within the dental circle to make dental hygienists' work execution in line with reality by improving and discussing a legal system for job assignment and expansion of workers. Therefore, it is required to form a plan for the many jobs dental hygienists executed in a clinical setting.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.1065-1072
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• 2010

The excavation site in the new city of inchon songdo is distributed with soft reclaimed soil and marine deposit. So, the general ground anchor is not applied to this layer of soft ground as the earth retaining support system, because of settlement. And then, Jacket pack anchor which is newly developed in order to increasing the pullout resistance by certain grout bulb formation and expansion effect in soft ground is applied to this site instead of the general ground anchor. Though the maximum horizontal displacement shows about 30mm~100mm (The maximum horizontal displacement/excavation depth$\fallingdotseq$0.32~1.0%) according to excavation sequence, generally excavation work finished stably. Also, load cell after setting shows almost increasing trend with increasing horizontal displacement. It means that the settlement of Jacket pack anchor in soft ground is good. From the result of this case, we knew that Jacket pack anchor was able to use the earth retaining support system in soft ground. Using Jacket pack anchor in soft ground, The allowance of the horizontal displacement is applied more than general value considering soil factors.

• The KIPS Transactions:PartD
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• v.10D no.5
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• pp.753-762
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• 2003

Many Methodologies have proposed for component retrieval. Among them, thesaurus concept has introduced for similar component retrieval. This paper classified classes by concept according to inheritance relation for efficient retrieval of component, and applied fuzzy logic to thesaurus method and constructed object-oriented thesaurus. Proposed method could express category between concepts automatically, and calculate fuzzy degree between classes by comparing matching and mismatching degree to each class and category and construct thesaurus. Component retrieval is that using classes of component, candidate components are retrieved according to priority order using fuzzy similarity. Also, we improved retrieval performance by thesaurus greatly, setting critical of most suitable through simulation.

• Archives of Plastic Surgery
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• v.45 no.5
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• pp.484-489
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• 2018

Large and ptotic breast reconstruction in patients who are not candidates for a transverse rectus abdominalis myocutaneous flap and revision surgery for the contralateral breast remains challenging. We developed a novel breast reconstruction technique using a latissimus dorsi myocutaneous (LD m-c) flap set at the posterior aspect of the reconstructed breast, combined with an anatomical silicone breast implant (SBI), following tissue expander surgery. We performed the proposed technique in four patients, in whom the weight of the resected tissue during mastectomy was >500 g and the depth of the inframammary fold (IMF) was >3 cm. After over-expansion of the lower portion of the skin envelope by a tissue expander, the LD m-c flap was transferred to cover the lower portion of the breast defect and to achieve a ptotic contour, with the skin paddle set at the posterior aspect of the reconstructed breast. An SBI was then placed in the rest of the breast defect after setting the LD m-c flap. No major complications were observed during the follow-up period. The proposed technique resulted in symmetrical and aesthetically satisfactory breasts with deep IMFs, which allowed proper fitting of the brassiere, following large and ptotic breast reconstruction.