• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.10a
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• pp.7-11
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• 2008

The fluorescent lamp is one of a discharge lane that is used by electric discharge to transfer from electrical energy to light The fluorescent lamp needs a ballast stabilizer when turn it on because it has negative resistance. Characters of electric discharge and transformed characters of ballast stabilizer are connected closely. Therefore, bring out best design directive that consider economical efficiency and term of a application is very important for both characters matching. In this case, we will team to develop tester and functions for expression for recognizing the end of fluorescent lamp life to solve fire problem and losing efficiency of light when a fluorescent lamp goes the end of the expected its life span.

• Structural Engineering and Mechanics
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• v.41 no.2
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• pp.231-242
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• 2012

This research work aims to develop an optimal design using Finite Element (FE) and Genetic Algorithm (GA) methods to replace the traditional concrete and timber material by a Synthetic Polyurethane fibre glass composite material in railway sleepers. The conventional timber railway sleeper technology is associated with several technical problems related to its durability and ability to resist cutting and abrading action of the bearing plate. The use of pre-stress concrete sleeper in railway industry has many disadvantages related to the concrete material behaviour to resist dynamic stress that may lead to a significant mechanical damage with feasible fissures and cracks. Scientific researchers have recently developed a new composite material such as Glass Fibre Reinforced Polyurethane (GFRP) foam to replace the conventional one. The mechanical properties of these materials are reliable enough to help solving structural problems such as durability, light weight, long life span (50-60 years), less water absorption, provide electric insulation, excellent resistance of fatigue and ability to recycle. This paper suggests appropriate sleeper design to reduce the volume of the material. The design optimization shows that the sleeper length is more sensitive to the loading type than the other parameters.

• Korean Institute of Interior Design Journal
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• v.17 no.6
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• pp.152-160
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• 2008

The Cases of advanced nations which have advanced welfare policy, they have headed for the deinstitutionalization and the protection of the local society. So they have expanded and improved the various policies and welfare facilities to be able to keep daily life on the base of local area. Many problems have been caused by rising the average life span of the elderly in Korea now. Under the tendency, there have been many alternative proposals to solve the problems. One of those proposals, the deinstitutionalization theory that is rated the ideal way, is the community-based care than the care in facilities for the elderly. It shows that the most ideal facility for the care is Daycare center and that it matters the system of spatial construction and standard of the facilities. Under the undetailed Korean standard of facility design, it is very important that system of spatial construction to correspond to the needs of the users and standard of the facilities are prepared from the point of view of the standard design of the domestic facilities for the elderly. The study of the book grasps the regional present situation of the domestic Daycare center and surveys the tendency of the stay and features of occupation of the user there through some case, and aims to have a thorough grip of the spatial scale by the user's behavior. It is to utilize for a proposal for preparation of the space scale, and an institution standard corresponding to user's needs in a Daycare center.

• Archives of design research
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• v.6 no.1
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• pp.23-46
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• 1993

The development of technology in modern industrial world which grows and changes every day is shortening the cycle of life span of products, so there is a flood of products around us. It is enough to say that this phenomenon leads to further emphasis on the aspect of design for human being. It is not a new fact that to design for the rational function and the modeling from to make a combination and to satisfy consumers' desire is a short cut to gain competitive superiority in developing new products for MIS security. Therefore the design which plays a leading role in the activity of creating more convenient, more aesthetic, and more econemical products is called 'NEW CORPORATE WEAPON'. The amount of effort made for developing products is different in each company, but recently the plan to develope new products and its process arouse more interest. This thesis purports to improve objective understanding about the development of design by investigating products development research and the process of analysis and designing as a case study on developing a domestic supersonic humidifier. This thesis consists of five chapters in all. In chapter one as a preface, the purpose the method and the scope of the study is described. Chapter two contains my effort to grasp the background of study on the design and the basic structure of supersonic humidifier. Chapter three is an examination into the present conditions of supersonic humidifier used in domestic and foreign area, and the shape of design. In chapter four, a guide for the development of design is established. The idea sketch based on a fundamental shape and the drawing are added to this. In chapter five on the basis of the result of analysis in the preceding research I describe the development of design of products on the premise that marketing gives proof for them but the products oriented by manufacturer are not included in this case. In this thesis, I try to recognize the process of the develpment of design and the importance of the plan for design in developing products by examining an investigative and analytic study on the design of products.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1740-1743
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• 2007

In this study, two types of fatigue tests were conducted. First, cyclic bending tests were performed using the micro-bending tester. A four-point bending test method was adopted, because it induces uniform stress fields within a loading span. Second, thermal fatigue tests were conducted using a pseudo power cycling machine which was newly developed for a realistic testing condition. The pseudo-power cycling method makes up for the weak points in a power cycling and a chamber cycling method. Two compositions of solder are tested in all test condition, one is lead-free solder (95.5Sn4.0Ag0.5Cu) and the other is eutectic lead-contained solder (63Sn37Pb). In the cyclic bending test, the solder that exhibits a good reliability can be reversed depending on the load conditions. The lead-contained solders have a longer fatigue life in the region where the applied load is high. On the contrary, the lead-free solder sustained more cyclic loads in the small load region. A similar trend was detected at the thermal cycling test. A three-dimensional finite element analysis model was constructed. A finite element analysis using ABAQUS was performed to extract the applied stress and strain in the solder joints. A constitutive model which includes both creep and plasticity was employed. Thermal fatigue was occurred due to the creep. And plastic deformation is main damage for bending failure. From the inelastic energy dissipation per cycle versus fatigue life curve, it can be found that the bending fatigue life is longer than the thermal fatigue life.

• Journal of The Korea Institute of Healthcare Architecture
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• v.5 no.9
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• pp.25-36
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• 1999

Today, a standard of living by the development of economy and science-technology is rapidly changing, and the average life span of the people has been lengthened by the improvement of medical services. As a result, the aging population has increased, and the Korea is likely to the aging society in 2020. However, the quality of the residential care facilities for the eldery stands for an elementery stage. Under such circumstance, the purpose of this study is to suggest the design guidelines to improve the quality of housing through the case studies of the spatial composition of the residential care facilities for the elderly people.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.788-789
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• 2011

A comprehensive thermo-electromagnetic model has been developed to estimate temperature and electromagnetic distribution in an three-phase induction motor under steady state operation. Electromagnetic modeling enables us to predict thermal dissipation rates by eddy-current loss and copper loss in induction motors. Non-uniform temperature distributions are investigated to account for the strong effect of local temperature build-up on the motor performance and expected life-span. For more accurate thermal modeling purpose, Heat loss mapping method, which is matched up with electromagnetic losses and volumetric heat source, is developed and performed analysis. Heat loss mapping method can be greatly used as a design or diagnostic tool for three-phase induction motors with complex structural electromagnetic fields.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.123-128
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• 1999

Recently, as a performance based design concept is introduced, assurance of expected performances on serviceability and safety in the whole span of life is exactly requested. So, quantitative assessments about durability related properties of concrete in early-age long term are come to necessary, Especially in early age, deterioration which affects long-term durability performance can be occurred by hydration heat and shrinkage, so development of reasonable hydration heat model which can simulate early age behavior is necessary. The micor-pore structure formation property also affects shrinkage behavior in early age and carbonations and chloride ion penetration characteristic in long term, So, for the quantitative assessment on durability performance of concrete, modelings of early age concrete based on hydration process and micor-pore structure formation characteristics are important. In this paper, a micromechanics based hydration heat evolution model is adopted and a quantitative model which can simulate micro-pore structure development is also verified with experimental results. The models can be used effectively to simulate the early-age behavior of concrete composed of different mix proportions.

• Computers and Concrete
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• v.19 no.3
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• pp.305-313
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• 2017

A robust finite element based reinforced concrete bridge deck corrosion initiation model is applied for time-dependent probabilistic sensitivity analysis. The model is focused on uncertainties in the governing parameters that include variation of high performance concrete (HPC) diffusion coefficients, concrete cover depth, surface chloride concentration, holidays in reinforcements, coatings and critical chloride threshold level in several steel reinforcements. The corrosion initiation risk is expressed in the form of probability over intended life span of the bridge deck. Conducted study shows the time-dependent sensitivity analysis to evaluate the significance of governing parameters on chloride ingress rate, various steel reinforcement protection and the corrosion initiation likelihood. Results from this probabilistic analysis provide better insight into the effect of input parameters variation on the estimate of the corrosion initiation risk for the design of concrete structures in harsh chloride environments.

• Journal of Auto-vehicle Safety Association
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• v.12 no.3
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• pp.27-33
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• 2020

In this paper, the process of predicting efficient durability performance for vibration durability test of automobile parts using vibration test load on automobile fuel tank is presented. First of all, the common standard load that can be applied to the initial development process of the automobile was used for the fuel tank and the vulnerability of the fuel tank to the vibration fatigue load was identified through frequency response analysis. In addition, the vulnerability of the fuel tank was re-enacted through vibration durability test results, and the scale factor was applied to the standard load. In order to predict the vibration durability performance required for detailed design, vibration fatigue analysis was performed on the developed vehicle with the frequency of vibration severity equivalent to the durability test, and the vulnerability and life span of the fuel tank were identified through the process of applying weights to these selected standard loads, thereby reducing the test time of the development vehicle.