• Proceedings of the KSME Conference
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• 2008.11a
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• pp.523-528
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• 2008

An open frame structure is fastened by bolt joints for strength and shock attenuation. Therefore the full finite element model of an open frame structure should be properly modeled including bolt joints for strength analysis of the frames and joint assemblies which are operated under multi-loading conditions such as driving, drop, inertia and torsional loads. Then the joints and frames must satisfy the specified allowable strength constraints. Because the full finite element model has a large number of elements to perform strength analysis, a detailed fine bolt analysis seems to be very expensive. Therefore bolts of the full finite element model are approximately modeled by constraints equations to constrain degree of freedoms between adjacent nodes. However, the constraints equation method can exaggerate stress results at the constrained nodes. Thus a detailed bolt analysis and a theoretical/experiential formula of bolts for a worst bolt joint are performed using reaction force applied both bolt and bolt joint. Finally, the results from the two methods are compared and discussed to verify the safety of the open frame structure.

• Nuclear Engineering and Technology
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• v.33 no.2
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• pp.209-224
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• 2001

The SSC-K system analysis code is under development at the Korea Atomic Energy Research Institute (KAERI) as a part of the KALIMER project. The SSC-K code is being used as the principal tool for analyzing a variety of off-normal conditions or accidents of the preliminary KALIMER design. The SSC-K code features a multiple-channel core representation coupled with a point kinetics model with reactivity feedback. It provides a detailed, one-dimensional thermal-hydraulic simulation of the primary and secondary sodium coolant circuits, as well as the balance-of-plant steam/water circuit. Recently a two-dimensional hot pool model was incorporated into SSC-K for analysis of thermal stratification phenomena in the hot pool. In addition, SSC-K contains detailed models for the passive decay heat removal system and a generalized plant control system. The SSC-K code has also been applied to the computational engine for an interactive simulation of the KALIMER plant. This paper presents an overview of the recent activities concerned with SSC-K code model development This paper focuses on both descriptions of the newly adopted thermal hydraulic and neutronic models, and applications to KALIMER analyses for typical anticipated transients without scram.

• The Journal of the Korea Contents Association
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• v.16 no.12
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• pp.70-77
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• 2016

In this study, we aim to obtain the fundamental data needed for the objective analysis and bio-mimetics of leeches, using x-ray imaging with radiation that allows 3D analysis of the detailed anatomic structures of leeches. It was confirmed that through using radiation, detailed images of leeches can be obtained, allowing 3D analysis of leeches' anatomical structures. Also, since the data obtained through the radiation allows you to observe the micro-structure, it can serve as a good resource for component analysis, as well as physiological and functional research. More, it is hoped to contribute to further research in the areas of bio-mimetics using leeches.

• Journal of Korean language education
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• v.28 no.2
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• pp.113-153
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• 2017

This thesis is an analysis of research topics among doctorate research papers in Korean education from 1990 to 2016. The purpose of this paper is to keep up with current trends of Korean Language Education research in South Korea and China. The study aims to provide relevant information to researchers majoring in Korean language education and to determine future directions of Korean language education. In this study, among a total of 1709 Korean and Chinese studies of Korean language education, a final selection of 444 doctoral thesis (which consist of a total of 389 papers in Korea and a total of55 papers in China) were chosen from 1990 to 2016. The final selection of 444 papers was classified by year, topics and methodologies with a detailed analysis of the content. In addition, a detailed analysis of future directions and challenges for Korean education within South Korea and China is provided.

• Special Issue of the Society of Naval Architects of Korea
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• 2015.09a
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• pp.69-73
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• 2015

An evaluation of the accidental limit state (ALS) for design of a semi-submersible drilling rig is one of the essential design requirements as well as ultimate limit state (ULS) and fatigue limit state (FLS). This paper describes the ALS evaluation on the explosion accident at shale shaker room of semi-submersible drilling rig. There are three steps for the ALS evaluation such as structural analysis at concept design, risk based safety design and structural analysis at detailed design. For the ALS evaluation at concept design, conceptual explosion overpressure from the Rule guided by the classification society was used in the structural analysis that was carried out using LS-DYNA. To set up the design accidental load (DAL), explosion analysis was carried out using FLACS taking safety barriers into consideration. Then, the structural analysis was carried out applying DAL for the ALS evaluation at detailed design. Through the ALS evaluation on the explosion at shale shaker room, the importance of the risk based safety design was described.

• Structural Engineering and Mechanics
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• v.30 no.6
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• pp.733-761
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• 2008

The failure of reinforced concrete structures in recent earthquakes caused concern about the performance of beam column joints. Confinement of joint is one of the ways to improve the performance of beam column joints during earthquakes. This paper describes an experimental study of exterior beam-column joints with two non-conventional reinforcement arrangements. One exterior beam-column joint of a six story building in seismic zone III of India was designed for earthquake loading. The transverse reinforcement of the joint assemblages were detailed as per IS 13920:1993 and IS 456:2000 respectively. The proposed nonconventional reinforcement was provided in the form of diagonal reinforcement on the faces of the joint, as a replacement of stirrups in the joint region for joints detailed as per IS 13920 and as additional reinforcement for joints detailed as per IS 456. These newly proposed detailing have the basic advantage of reducing the reinforcement congestion at the joint region. In order to study and compare the performance of joint with different detailing, four types of one-third scale specimens were cast (two numbers in each type). The main objective of the present study is to investigate the effectiveness of the proposed reinforcement detailing. All the specimens were tested under reverse cyclic loading, with appropriate axial load. From the test results, it was found that the beam-column joint having confining reinforcement as per IS: 456 with nonconventional detailing performed well. Test results indicate that the non-conventionally detailed specimens, Type 2 and Type 4 have an improvement in average ductility of 16% and 119% than their conventionally detailed counter parts (Type1 and Type 3). Further, the joint shear capacity of the Type 2 and Type 4 specimens are improved by 8.4% and 15.6% than the corresponding specimens of Type 1 and Type 3 respectively. The present study proposes a closed form expression to compute the yield and ultimate load of the system. This is accomplished using the theory of statics and the failure pattern observed during testing. Good correlation is found between the theoretical and experimental results.

• Korean Journal of Construction Engineering and Management
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• v.24 no.3
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• pp.3-11
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• 2023

This research examines the need for a quantitative and objective method of calculating baseline productivity in the construction industry, which is known for its high volatility in performance and productivity. The existing literature's baseline productivity calculation methods rely heavily on subjective criteria, limiting their effectiveness. Additionally, data collection methods such as the "Five-minute Rating" are costly and time-consuming, making it challenging to collect detailed data at construction sites. To address these issues, this study proposes an objective baseline calculation method using unimpacted productivity BP, a work check sheet to systematically record detailed data, and a data collection and utilization process that minimizes cost and time requirements. This paper also suggests using unimpacted productivity BP and comparative analysis to address the objectivity and reliability issues of existing baseline productivity calculation methods.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.3
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• pp.354-362
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• 2008

This paper presents the new method of power system transient stability simulation, which combines the desirable features of both the time domain technique based on OOP(Object-oriented Programming) and the direct method of transient stability analysis using detailed generator model. OOP is an alternative to overcome the problems associated with the development, maintenance and update of large software by electrical utilities. Several papers have already evaluated this approach for power system applications in areas such as load flow, security assessment and graphical interface. This paper applied the object-oriented approach to the problem of power system dynamics simulation. The modeling method is that each block of dynamic system block diagram is implemented as an object and connected each other. In the transient energy method, the detailed synchronous generator model is so-called two-axis model. For the excitation model, IEEE type1 model is used. The developed mothed was successfully applied to New England Test System.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.1009-1014
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• 2002

In this study, developed economical and scientific Pavement Management System(PMS) that can produce suitable maintenance method through judgement and analysis of pavement condition exactly, to overcome past unscientific pavement management limitations. First, on the basis of data of the inside and outside of the country on PMS, composed logical algorithm such as pavement condition investigation and analysis, detailed naked eye investigation, whole system estimation etc., and it verified that this algorithm is suitable system through the inside and outside of the country PMS research examples and results of detailed naked eye investigation. Also, developed easily usable PMS program and PMS_GIS program with such logical algorithm.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.432-437
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• 2004

In this study, Pavement Management System(PMS) was developed to overcome the unscientific pavement management limitations of the past. PMS program is economic, efficient and scientific. Also, it produces the best maintenance method through exact judgement and logical analysis of pavement condition. First of all, the logical algorithm, that is such as investigation and analysis of pavement, detailed naked eye investigation and the estimation for whole system etc., was composed on the basis of the domestic and the outside data on PMS and pavement condition data of Seoul metropolitan. And then it was verified that this algorithm is suitable through the research examples of PMS data and the results of detailed naked eye investigation. Also, Geographic Information System(GIS) was integrated on PMS program. Therefore, PMS program was developed so as to use easily on the basis of the logical algorithm.