• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1998.04a
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• pp.136-142
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• 1998

Despite the fact that vibration and noise of suction and discharge valves are important factors to be considered in reciprocating compressor designs, such are still have many problems to be developed. Subsequently, this paper addresses a thorough investigation to retrieve basic data for designing suction and discharge valve. In achieving this goal, the natural frequencies in suction and discharge valve were calculated using finite elements method and compared with the results of experimental method which is driven by the speaker and detected by the Laser Velocity Transducer. Also, it was found that natural frequencies are much affected by the Young's Modulus at the clamp. Therefore, improved experimental setup is suggested to consider the effect of clamping conditions. Consequently improved experimental data have good agreements with the FEM data.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.12
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• pp.2061-2071
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• 2003

The macro-parametric approach, which is a method of CAD model exchange, has recently been proposed. CAD models can be exchanged in the form of a macro file, which is a sequence of modeling commands. As an event-driven commands set, the standard macro file can transfer design intents such as parameters, features and constraints. Moreover it is suitable for the network environment because the standard macro commands are open, explicit, and the data size is small. This paper introduces the concept of the macro-parametric method and proposes its representation using XML technology. Representing the macro-parametric data using XML allows managing vast amount of dynamic contents, Web-enabled distributed applications, and inherent characteristic of structure and validation.

• Korean Management Science Review
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• v.10 no.1
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• pp.59-80
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• 1993

Electronic data interchange (EDI) is a new technology of information communication which can make offices paperless. This study develop an EDI system to communicate informations among companies using computer systems. The system consists of five modules-document I/O, translation, system management, communication, and additional modules. The database of EDI documentation standards has been constructed by the table-driven method. The communication module provides three communication modes-RS232C, MODEM, and message handling system (MHS). The system performance has been improved by the method of data compression and data encryption which prevent the communication delay and illegal users. This EDI system can be used as a front-end, back-end, or stand-alone mode.

• Journal of the military operations research society of Korea
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• v.31 no.2
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• pp.105-115
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• 2005

To ensure interoperability among TADILs, we need inter-operational system of tactical data link that allows sharing of specific, planned information among different TADILs. In this paper, we have proposed the design of a conceptual software architecture of inter-operational system. For developing of a conceptual software architecture, we analyze the actual condition of ADSI used in the US military and identify functions and quality-attributes. Based on these factors, we design the conceptual software architecture for inter-operational system of tactical data link using Attribute-Driven Design(ADD) method. ADD is consist of three phases - choose the module to decompose, refine the module, repeat the steps for every module that needs further decomposition. To evaluate of ADD results, we apply the Software Architecture Analysis Method(SAAM) which is consist of making evaluation scenarios, choosing indirect scenarios, evaluation scenarios' interaction, and creating an overall evaluation. Through the evaluation, we verify the conceptual software architecture of inter-operational system.

• Journal of Information Processing Systems
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• v.20 no.3
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• pp.285-295
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• 2024

Driven by the vague assessment big data, a product service system (PSS) evaluation method is developed based on a hybrid model of multi-weight combination and improved TOPSIS by relative entropy. The index values of PSS alternatives are solved by the integration of the stakeholders' vague assessment comments presented in the form of trapezoidal fuzzy numbers. Multi-weight combination method is proposed for index weight solving of PSS evaluation decision-making. An improved TOPSIS by relative entropy (RE) is presented to overcome the shortcomings of traditional TOPSIS and related modified TOPSIS and then PSS alternatives are evaluated. A PSS evaluation case in a printer company is given to test and verify the proposed model. The RE closeness of seven PSS alternatives are 0.3940, 0.5147, 0.7913, 0.3719, 0.2403, 0.4959, and 0.6332 and the one with the highest RE closeness is selected as the best alternative. The results of comparison examples show that the presented model can compensate for the shortcomings of existing traditional methods.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.6C
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• pp.367-377
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• 2008

As part of study to develop LRFD (Load and Resistance Factor Design) codes for foundation structures in Korea, resistance factors for static bearing capacity of driven steel pipe piles were calibrated in the framework of reliability theory. The 57 data sets of static load tests and soil property tests conducted in the whole domestic area were collected and these load test piles were sorted into two cases: SPT N at pile tip less than 50, SPT N at pile tip equal to or more than 50. The static bearing capacity formula and the Meyerhof method using N values were applied to calculate the expected design bearing capacities of the piles. The resistance bias factors were evaluated for the two static design methods by comparing the representative measured bearing capacities with the expected design values. Reliability analysis was performed by two types of advanced methods: the First Order Reliability Method (FORM), and the Monte Carlo Simulation (MCS) method using resistance bias factor statistics. The target reliability indices are selected as 2.0 and 2.33 for group pile case and 2.5 for single pile case, in consideration of the reliability level of the current design practice, redundancy of pile group, acceptable risk level, construction quality control, and significance of individual structure. Resistance factors of driven steel pipe piles were recommended based on the results derived from the First Order Reliability Method and the Monte Carlo Simulation method.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.5
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• pp.2406-2414
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• 2013

The data-driven IT project model has been improved by adding processes such as analysis/design of data structure and channels of data collection/distribution, application of data standard and securing the flexibility in IT convergence devices data configuration on existing informatization project procedure driven by HW and SW function. This model focused on the evaluation of improvement effect which warrants data flexibility of IT convergence device. IT convergence device was divided into sensor and reactor and a situation when new information system is additionally linked to these devices was assumed. The system improvement complexity and index on network environment were estimated and they were compared to existing method.

• International Journal of Computer Science & Network Security
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• v.23 no.2
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• pp.133-139
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• 2023

As the old saying goes "a picture is worth a thousand words" data visualization is essential in almost every industry. Companies make Data-driven decisions and gain insights from visual data. However, there is a need to investigate the role of data visualization in human resource management. This review aims to highlight the power of data visualization in the field of human resources. In addition, visualize the latest trends in the research area of human resource and data visualization by conducting a quantitative method for analysis. The study adopted a literature review on recent publications from 2017 to 2022 to address research questions.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2901-2906
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• 2007

A solver for icing and condensation of water has been developed. The phase change process was solved by the enthalpy method. For the code validation, the temperature and the phase change from water to ice of the driven cavity were calculated. Also, the melting process of the frost on the windshield glass of an automobile has been simulated. The calculation showed a good agreement with analytical solution and other numerical results. Using the present validated code, the condensation of water vapor has been first tried. The computed results provided some physical features of condensation phenomena even though experimental data and other numerical data were not available. For future work, it is recommended to throughly investigate the effects of boundary conditions on the solution.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.84-89
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• 2014

Data-driven method for fault diagnostics system often use machine learning technique. To use such technique proper signal processing should be implemented such as time synchronous averaging (TSA) for ball bearing systems. However, for journal bearing diagnostics systems not much has been researched, and yet a proper signal processing method has not been studied. Therefore, in this research an optimal datum unit for a reliable journal bearing diagnostics system along with angular resampling process is being suggested. Before extracting time and frequency domain features, angular resampling is applied to each cycle of vibration data. As to preserve the characteristics of vibration signal, averaging method is replaced by finding the optimal datum unit which strengthens statistical characteristics of vibration signal. Then 20 features were extracted for various cases, and those features are being evaluated by two criteria, separability and classification accuracy.