• Journal of the Korean Operations Research and Management Science Society
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• v.17 no.1
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• pp.117-117
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• 1992

Pubilc utility industries including the electric utility industry are facing a new stream of privatization com-petition with the private sector and deregulation. The necewssity to solve now and in the future power supply and demand problems has been increasing through the sophisticated generation expansion plan(GEP) approach con-sidering not only KEPCo's supply-side resources but also outside resources such as non-utility generation(NUG) demand-side management (DSM). Under the environmental situation in the current electric utility industry a new approach is needed to acquire multiple resources competitively. This study presents the development of a modified electric generation expansion analysis system(EGEAS) model with avoided cost based on the existing EGEAS model which is a dynamic program to develope an optimal generation expansion plan for the electric utility. We are trying to find optimal GEP in Korea's case using our modified model and observe the difference for the level of reliabilities such as the reserve margin(RM) loss of load probability(LOLP) and expected unserved energy percent(EUEP) between the existing EGEAS model and our model. In addition we are trying to calculate avoided cost for NUG resources which is a criterion to evaluate herem and test possibility of connection calculation of avoided cost with GEP implementation using our modified model. The results of our case study are as follows. First we were able to find that the generation expansion plan and reliability measures were largely influenced by capacity size and loading status of NUG resources, Second we were able to find that avoided cost which are criteria to evaluate NUG resources could be calculated by using our modified EGEAS model with avoided cost. We also note that avoided costs were calculated by our model in connection with generation expansion plans.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.03a
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• pp.513-520
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• 1999

20 million tons of coal ash has been produced in Korea annually. This causes the environmental problems and the cost of land for ash pond. However the amount of coal ash for recycling is small because of the low level of recycling technology and the ignorance. As the coal ash has the significant engineering properties, it can be utilized as soft ground stabilizer, backfill materials and so forth. The purpose of this paper is to summarize some of the recycling methods of coal ash. One is structural backfill materials, the other is flowable fill. Optimal mixture ratio(fly ash : bottom ash) is determined for structural backfill materials and the model test is performed. The model test accompanied with physical tests were executed for identifying that the flowable fly ash can be used as fill materials such as trench back filling.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.8
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• pp.37-44
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• 2008

Nowadays, the increasing global competition forces manufacturer to reduce the cost and time for implementation of manufacturing system. The AR(augmented reality) technology as a new human-machine interface introduces a noteworthy perspective for a new manufacturing system design. Using AR technology, a physically existing production environment can be superimposed with virtual planning objects. Therefore, the planning tasks can be validated without modeling the surrounding environment of the production domain during short process planning time. In this paper, we introduce the construction of AR browser and determine the optimal environment parameters for field application of AR system through lots of tests. And, many methods such as multi-marker coordinate system, division of virtual objects and so on, are proposed in order to solve the problems suggested from initial field test. Based on these tests and results, the test-bed of C/Pad assembly system is configured and robot program for C/Pad assembly is generated based on AR system.

• Transactions of Materials Processing
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• v.23 no.2
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• pp.110-115
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• 2014

Low cycle fatigue characteristics are very important in the development of automobile suspension parts. Fatigue properties using the strain life approach are usually obtained from low cycle fatigue tests. However, low cycle fatigue testing requires a lot of time and cost. In the current study, an attempt to estimate low cycle fatigue properties of high strength steel sheet from tensile test and tensile simulations is performed. In addition, low cycle fatigue testing was conducted to compare the fatigue properties obtained from tensile testing and simulations. In conclusion, the results effectively predict the low cycle fatigue properties. However, some deviations still exist.

• KIEAE Journal
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• v.7 no.2
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• pp.71-76
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• 2007

For the many years the children's running noise has caused perpetual frictions between neighbors in apartment houses. For this reason the government established a regulation to reduce the floor impact noise, as a result almost all apartment houses have been enforced to use the floor structure with 210mm thickness concrete slab and 120mm thickness of floor heating system since July 2005. If do not want to apply this kind of system, a system which obtain the certification from the institution appointed by government must be applied. In this reason a lot of construction material companies and construction companies have been trying to develop the system with 180mm thickness concrete slab for the purpose of reducing the cost. To develop the optimized floor system, actual size test building were constructed and the materials related with reducing floor impact noise were composited and tested in the test building. Through this procedure the most effective system was found.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.78.1-78.1
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• 2010

Recently, as much supplied with new-renewable energy, as much invested in PV system. PV system consists of PV module, PCS and Monitering system, and also could be classified into the type and the capacity by installation method and cost etc. When various systems are installed in the field, it is needed to research for applying in the field and establish infrastructure in order to ensure stable efficiency and reliability. In this study, as the basic design of the demonstration test facility, it is designed the basic PV systems for each capacity to test each PCS. In addition, It is drew the climatic conditions such as insolation, temperature and the design parameters such as installation angle, shades for the local demonstration project and expected the generation of each PV system.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.3
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• pp.18-25
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• 1998

This paper performed stress analysis and bench test for the LOWER ARM of H' type which was improved on LOWER ARM with the section of H type. And we investigated the safety of the section of H' type. The results of this study are as follows ; The section of H' type satisfied the required safety factor and has the highest stress value on the B part of the LOWER ARM. And the magnitude is similar to the fatigue strength of the GCD45(300㎫). Hence, the H' type has an advantage to reduce the cost of production.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.15-218
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• 1999

Concrete is the most generous, universal main structural material. There is active study for processing quality, stable quality mangement. Especially, strength is basic factor of evaluating stability of concrete building. Regaining required strength and homogeneity is very important to get self-stability in building to evaluate another characteristic. Concrete strength is important to the quality management. But, result of hardened concrete's quality test is hardly reflected to works immediately. When required strength is not enough, it could bring out safe problem, economic and administrative cost. It is pointed out that problems from strength evaluation, so early evaluation of concrete quality is required. From the trend that accelerating high quality concrete development, improving the method of quality test and early evaluation measure is urgent project. Throughout this report, it is suggested the method with use of microwave to evaluate 28-days concrete strength.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.757-762
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• 2001

CFT concrete has high flowing, high strength and resistance to material separation to use skyscraper structure. It is considered that concrete could fill the lower part of Diaphragm up. This kinds of CFT concrete hardly apply to building below 20 stories. Using the common use strength concrete to building below 20 stories brings to reduce construction cost. This concrete is needed that valid fluidity and packing ability with unit cement content as common use strength concrete. Offering a fundamental data and proportioning in CFT concrete of below 20 stories, it is executed basic property test, analysis of proportioning and mock up test.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.9
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• pp.71-77
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• 2020

In recent years, as a consequence of the technological advancements in the automobile industry and changes in consumer demands, the reduction of noise inside vehicles rather than vehicle performance has increasingly become an important factor of interest. To date, most studies have focused on noise and vibration reduction techniques for the engine and drive system of vehicles. In this research, a comparative analysis for reducing the effect of vehicle seatbelts on the transient response is performed using the test of vehicle conditions and transient response analysis in accordance with seatbelt conditions. After the sensitivity analysis, the specifications for improvement were designed based on the transient response analysis. It was confirmed that the transient response characteristics were improved by the transient response analysis and vehicle conditions test. Through computer-aided engineering, the transient response characteristics of seatbelts were checked with less cost and time.