• International Journal of Concrete Structures and Materials
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• v.7 no.4
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• pp.319-332
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• 2013

The purpose of this study was to investigate the design comparison of totally prefabricated bridge substructure system. Prefabricated bridge substructure systems are a relatively new and versatile alternative in substructure design that can offer numerous benefits. The system can reduce the work load at a construction site and can result in shorter construction periods. The prefabricated bridge substructures are designed by the methods of Korea Highway Bridge Code (KHBD) and load and resistance factor design (AASHTO-LRFD). For the design, the KHBD with DB-24 and DL-24 live loads is used. This study evaluates the design method of KHBD (2005) and AASHTO-LRFD (2007) for totally prefabricated bridge substructure systems. The computer program, reinforced concrete analysis in higher evaluation system technology was used for the analysis of reinforced concrete structures. A bonded tendon element is used based on the finite element method, and can represent the interaction between the tendon and concrete of a prestressed concrete member. A joint element is used in order to predict the inelastic behaviors of segmental joints. This study documents the design comparison of totally prefabricated bridge substructure and presents conclusions and design recommendations based on the analytical findings.

• Earthquakes and Structures
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• v.9 no.3
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• pp.455-480
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• 2015

In the last decade, displacement-based (DB) methods have become established design procedures for reinforced concrete (RC) structures. They use strain and displacement measures as seismic performance control parameters. As for other simplified seismic design methods, it is of great interest to prove if they are usually conservative in respect to more refined, nonlinear, time history analyses, and can estimate design parameters with acceptable accuracy. In this paper, the current Direct Displacement-Based Design (DDBD) procedure is evaluated for designing simple single degree of freedom (SDOF) systems with specific reference to simply supported RC bridge piers. Using different formulations proposed in literature for the equivalent viscous damping and spectrum reduction factor, a parametric study is carried out on a comprehensive set of SDOF systems, and an average error chart of the method is derived allowing prediction of the expected error for an ample range of design cases. Following the chart, it can be observed that, for the design of actual RC bridge piers, underestimation errors of the DDBD method are very low, while the overestimation range of the simplified displacement-based procedure is strongly dependent on design ductility.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.31 no.3
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• pp.287-295
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• 1995

fishing boat is a specialized vessel which is intended to perform certain well defined tasks. Its size, deck-layout, carrying capacity and equipment are all related to its function in carrying out its planned operations. Therefore the process of fishing boat design is inherently combined with optimization of the design variables called the economic optimization criteria. Optimization then is a process in which minimum value of weight or cost is established through evaluation of consecutive designs in which one or more design parameters are varied. This paper is to study the basic-design of Stow-net fishing vessel in the Mok-Po region. The main task is developed the preliminary design model of engineering economic system in order to use optimization techniques from operation research the design problem needs to be expressed in terms of objective function and numerous constrains like : speed, fish hold capacity, fishing range, displacement and weight, ratio of main dimensions, etc. The objective function represents the criterion which is NPV such as the ratio of revene/cost. When using computers of limited capacity like P/C, the developed basic-design model of the economic optimization procedure must be simplified to V, Cb, L/B, Dv, Db and less than 15 constraint equations. The main conclusions of this study have attempted to show that economic considerations are essential in Stow-net fishing vessel basic design and operations, and that techno-economic evaluation is an important tool for the design of Stow-net fishing vessel in 69ton and 79ton.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.7
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• pp.4849-4854
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• 2015

It has been often occurred for the outside components(BU, SVaC, DB) of UM71c AF track circuits to be broken down caused by some pieces of falling ice in the winter time or by infrastructure repairing equipments while facility maintenance works since 2004, opening of Kyeongbu High Speed Rail Express. In this paper, we proposed that we could move the outside components of UM71c track circuit out of wayside from present place. Then we can assure that the life time of those components would be extended. So we simulated the electrical characteristics by changing cable length using MATLAB Simulinks and we designed the compensation capacitor. Also, we obtained the same results as those of simulation by field demonstration test on site. The design specifications obtained from this field verification test could be applied in the absent section of track circuit, if only have a little more intensified research to compensate changed electrical characteristics and to redesign inner impedance of the track circuit.

• The Journal of Industrial Distribution & Business
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• v.8 no.2
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• pp.21-31
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• 2017

Purpose - The total amount of advanced Corporate Pension Insurance products exceed 148 trillion Korean Won at the end of 2016. For a firm with over 300 employees, when a bill on compulsion of introduction of Corporate Pension Insurance products, currently pending in court, is passed, Corporate Pension shall be an essential. The findings of the paper will provide a guideline for understanding on firm's attributes and its effects towards introduction of Corporate Pension Insurance products. Research design, data, and methodology - The data were collected using statistics of employer panel survey from Korea Labour Institute in 2013. The study analyses a sample survey on 1,775 outstanding enterprises and their HR department among whole corporations in Korea. For analysis of data, empirical testing by Logistic Regression was utilized. Results - As an outcome of empirical testing, variables on share of regular employees and the aged employees in over 50's generates a significant statistical meaning. It eventually gives a great impact on purchase of Corporate Pension scheme. Moreover, variables on corporate financial statement, current sales, current net income, total amount of the debts, labor cost per person also has a vital influence on introduction of Corporate Pension Insurance products. Lastly, variables on firm's labor relationship have no effect except for the execution or non-execution of HR consulting. Meanwhile, Variables affecting a choice on pension schemes types among firm's attributes are a share of regular employees, current net income, execution or non-execution of HR consulting etc. These variables represents a statistical implication. According to their each features, they prefer DB or DC plan. Conclusions - Introduction of corporate pension scheme is apposite to contemporary Korea's situation entering a hyper-aging society and firms with a high share of regular employees, the weight of aging, current sales, current net income and labor cost per person are exceedingly active in purchasing Corporate Pension Insurance products. However, after the introduction of corporate pension scheme, firms which has an implementation of consultation on human resource management, flexible benefits plan, job security and welfare system prefer DC plan whereas from financial perspective firms with high net income prefer DB plan.

• Journal of Korea Multimedia Society
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• v.14 no.3
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• pp.433-439
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• 2011

The positioning system based on wireless AP collects AP information distributed in the real world, stores it into database, and measures the position objects by comparing with searched AP information. The existing fingerprinting method is a probabilistic modeling method that acquires much of the data collected from one location upon database composition, and stores the average of the data for the sake of use it in positioning objects. Using the average value, however, may cause the probability of errors Such errors are fatal weaknesses for services based on the accurate position. This paper described the characteristics and problems of the previously used wireless AP positioning system, and proposed a method of using the AP DB and an MSS mechanism for outdoor positioning in order to solve the aforementioned problems. And the results obtained from experimental tests showed that the proposed method achieved very low error rate(27%) compared with the existing method.

• Journal of the Korean Institute of Gas
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• v.12 no.1
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• pp.13-18
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• 2008

Vibration velocity induced by earthquakes or external vibration sources is one of the integrity assessment indexes, and is also a representative value used to describe the amount of vibration because it is based on a proportional relationship with the damage scale. In this study, the vibration velocity criterion for structures is first examined. Then, based on the velocity criterion, an integrity assessment is performed. Burial condition is set up based on the "Highway and Local Road Design Criteria" with API 5L Gr. X65 pipeline(D=762 mm). The FE model considers DB-24 vehicle load as a time function with a varying velocity in the range of $20{\sim}160\;km/h$. Maximum vibration velocity occurs at v=80 km/h and decreases after v=80 km/h. The maximum vibration velocity of buried pipeline by DB-24 loads is about 0.034 cm/s. The velocity that occurs is in the range of allowable values for each vibration velocity criterion. The wave propagation velocity was identified based on attenuation law and the minimum value appears at vehicle velocity 80 km/h that has maximum vibration velocity.

• Proceedings of the Korea Contents Association Conference
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• 2005.11a
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• pp.433-437
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• 2005

Most research organizations, universities and enterprises manage the transaction informations (customer informations, account informations, transaction results and so on), which is a fundamental item in the part of buying and research capital expenditure for the execution of R&D project or relative works. But because they don't only manage transaction information systematically but also don't put to practical use as sharing knowledge, many researchers duplicate their operations and it is shown a drop in efficiency. Also there are many problems because useful informations are unapproachable in the side of research management. In this paper, we propose the database design, application plan and service method for joint utilize of transaction information. And we prove the proposed method by service which is operated within intranet system. The transaction information shared by the proposed method will be useful knowledge and a major factor of efficiency improvement in research management field.

• The KIPS Transactions:PartB
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• v.12B no.5 s.101
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• pp.595-606
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• 2005

The scale of game development are rapidly increasing as the blockbuster games which cost $7\~20$ billion won, often appear on the markets. The game mechanics which is concentrated on technological elements of the game, necessarily requires the management of quality. In this paper, we propose a computer simulator for the quality evaluation of game mechanics which can analyze the quality accurately and economically in the design phase. The proposed simulator provides Petri net[7,8] and Smalltalk[9] for convenient modeling. The simulator gives the realistic evaluation like play test because it uses the realistic data of gameplay environment such as player action-pattern, game world map, and item DB but the previous evaluation methods can not consider the realistic gameplay environment and can only cover a limited scope of evaluation. To prove good performance of the proposed simulator, we have 80 simulations for the quality evaluation of the game mechanics of Dungeon & Dragon[13,14] in a given world map. The simulation results show that the proposed simulator can evaluate the faultlessness, optimization, and play balance of the game mechanics and gives better good performance than other evaluation methods.

• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.4
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• pp.64-75
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• 2008

Since the current database systems for managing geotechnical investigation results were limited by being described boring test result in point feature, it has been trouble for using other GIS data. Although there are some studies for spatial characteristics of subsurface modeling, it is rather lack of being interoperable with GIS, considering geotechnical engineering facts. This is reason for difficulty of practical uses. In this study, we has developed subsurface spatial information model through extracting needed geotechnical engineering data from geotechnical information DB. The developed geotechnical information clustering program(GEOCL) has made a cluster of boring formation(and formation ratio), classification of layer, and strength characteristics of subsurface. The interpolation of boring data has been achieved through zonal kriging method in the consideration of spatial distribution of created cluster. Finally, we make a subsurface spatial information model to integrate with digital elevation model, and visualize 3-dimensional model by subsurface spatial information viewing program(SSIVIEW). We expect to strengthen application capacity of developed model in subsurface interpretation and foundation design of construction works.