• Proceedings of the KWS Conference
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• 2002.10a
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• pp.169-175
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• 2002

World demand for natural gas has generated the need for many new land transmission pipelines to be installed in the next decade or so. Although mechanized gas metal arc welding is well developed, there are opportunities for cost savings by using alternative welding processes. Hybrid Nd:YAG laser - gas metal arc welding enables fibre optic delivery of the laser energy to a robotic welding head to be combined with the addition of extra energy and a consumable to produce good quality, deep penetration welds in a single pass. The present paper describes initial procedure development to optimize the laser and gas metal arc welding parameters for making joints in pipeline steel. Satisfactory joint quality was obtained and it is intended to develop the process to prototype field trials.

• Proceedings of the Korea Association of Information Systems Conference
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• 2003.05a
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• pp.241-251
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• 2003

The rapidly changing environment have forced organizations to improve systems thinking capability to coordinate diverse activities across cross-functional business areas necessarily involving group decision-making processes. Although many approaches have been introduced to enable the collaborative processes of group decision-making, they often lack features supporting the dynamic complexity issues. The study proposes system dynamics modeling based on simulation techniques to improve systems thinking capability in group decision-making context.

• Management Science and Financial Engineering
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• v.10 no.1
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• pp.1-23
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• 2004

The changing structure of organization and the increasing diversity of business have forced organizations to have abilities to coordinate dispersed business activities. They have required cooperation and coordination among the functional units in the organization which should involve group decision-making processes. Although many group decision-making support tools and methods have been introduced to enable the collaborative process of group decision-making, they often lack the features supporting the dynamic complexity issue frequently occurring at group decision-making processes. This results in cognitive unfit between the group decision-making tasks and their supporting tools, bringing about mixed results in their effects on group decision-making. This study proposes system dynamics modeling as a group decision-making support tool to deal with the group decision -making tasks having properties of dynamic complexity in terms of cognitive fit theory.

• Phonetics and Speech Sciences
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• v.9 no.2
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• pp.23-29
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• 2017

This paper investigated the phonological processes of monophthongs and diphthongs in pronounced phrasal words of the Seoul Corpus by gender and age groups in order to provide linguists and phoneticians with a clearer understanding of the spoken Korean. Both orthographic and pronounced phrasal words were extracted from the transcribed label scripts of the Corpus using Praat. Then, phonological processes of monophthongs and diphthongs were tabulated using an R script after syllabifying the phrasal words into separate components. Results revealed that 97% of the number of syllables in the orthographic and pronounced phrasal words were the same while 65.8% showed difference in the syllable structure. 90.5% of the vowels in the orthographic phrasal words were realized in the pronounced phrasal words. A Chi-square test of independence was performed to obtain a significant dependence in the distribution of phonological process types of male and female groups along with a very strong correlation. Female group changed the diphthong yo into yv at the end of the pronounced phrasal words more often than the male group did. Age groups also showed a significant dependence in the distribution of phonological process types along with a very strong correlation. Females in the 40s produced the diphthong yv and made the vowel raising at the end of the pronounced phrasal words most often among the gender and age groups. From the results, this paper concludes that an analysis of phonological processes in light of syllable structure can contribute greatly to the understanding of the spoken Korean.

• Transactions of the Korean hydrogen and new energy society
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• v.33 no.5
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• pp.499-506
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• 2022

This study proposes kinetic parameters of Ru catalyst for steam methane reforming (SMR). First, extensive experiments are performed under different SMR conditions to evaluate performance of the catalyst in SMR. Second, a kinetic model is designed and developed for parameter estimation and validation using gPROMS. Finally, estimated parameters are fitted to the kinetic model and then, the model results are compared with the experimental data. The model results are in a good agreement with the experimental data.

• Journal of Korean Society for Quality Management
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• v.26 no.2
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• pp.61-81
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• 1998

This research studies the role of IT (Information Technology) in improving productivity of a company through samll group activities. For this purpose, this research analyzed the samll group activities of the company as to how IT was employed bo improve business processes. Cases of small group activities that were conducted from January, 1996 to December, 1996 in a Korean company (name withdrawn) were analyzed. Eight out of eleven small group activities have been studied. They were examined as to the effect of IT in time and cost savings, reduction in manpower and so on. TQM is the activity of process improvement based on the existing processes in pursuit of satisfaction of customers' needs. This study analyzed how IT was used to solve the current problem in business processes. As a result of the case study, it is found that TQM activities with IT could reduce expenses significantly. More specifically, expenses have been cut down by 56% a year on average. By improving the business processes through the activities of TQM which used IT, companies could remove the unnecessary business processes and the duplicated business processes. In other words, with the use of IT in TQM activities, they could move closer to goals of the satisfaction of the customers' needs by reducing expenses and time. This study examined the role of IT from the point of view of business process improvement. Internally, IT has a positive impact on reducing expenses, processing time, manpower and so forth. Externally, it plays an important role of company's gaining competitive advantage through the satisfaction of customers and stakeholders. In conclusion, the proper use of IT will significantly increase the performance of a company.

• Journal of the Korean institute of surface engineering
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• v.55 no.6
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• pp.363-367
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• 2022

Transparent ZnO/Ti/ZnO (ZTZ) tri-layered films were prepared with radio frequency (RF) and direct current (DC) magnetron sputtering on the glass substrate. The thickness of the ZnO and Ti films was kept at 50 and 10 nm to consider the effect of the electron irradiation on the crystallization and optoelectrical properties of the films. From the XRD spectra, post-depostion electron irradiated films showed the characteristic peaks of ZnO(002) and Ti(200), respectively. the observed grain size of the ZnO(002) and Ti(200) enlarged up to 18.27 and 12.16 nm at an irradiation condition of 750 eV. In the figure of merit which means an optoelectrical performance of the films, as deposited films show a figure of merit of 2.0×10^-5 𝛺^-1, while the films electron irradiated at 750 eV show a higher figure of merit of 5.7×10^-5 𝛺^-1.

• Journal of the military operations research society of Korea
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• v.16 no.2
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• pp.29-42
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• 1990

This paper describes a Battle Group Combat Simulation Model (called 'BAGSIM'). BAGSIM is developed to be used as an experimental tool for studies about combat modelling at battle group level. Thus it takes many of the parameters and situations into consideration at this level, and it is designed to be easily adapted to represent equivalent situations to the other more aggregated models. Further the main processes occurring in its simulation procedure such as target detection process, target selection process, firing and killing processes are verified by comparison with the existing stochastic duel models.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.2
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• pp.83-88
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• 2018

Additive manufacturing (AM) technologies have attracted wide attention as key technologies for the next industrial revolution. Among AM technologies using various materials, powder bed fusion (PBF) processes and direct energy deposition (DED) are representative of the metal 3-D printing process. Both of these processes have a common feature that the laser is used as a heat source to fabricate the 3-D shape through melting of the metal powder and solidification. However, the material properties of the deposited metals differ when produced by different process conditions and methods. 17-4 precipitation-hardening stainless steel (17-4PH SS) is widely used in the field of aircraft, chemical, and nuclear industries because of its good mechanical properties and excellent corrosion resistance. In this study, we investigated the differences in microstructure and mechanical properties of deposited 17-4PH SS by PBF and DED processes, including the heat treatment effect.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2002.11a
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• pp.53-56
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• 2002

This paper discusses the quorum based algorithm for group mutual exclusion defined by Yuh-Jzer Joung. Group mutual exclusion[4,5,6] is a generalization of mutual exclusion that allows a resource to be shared by processes of the same group, but requites processes of different groups to use the resource in a mutually exclusive style. Joung proposed a quorum system, which he referred to as the surficial quorum system for group mutual exclusion and two modifications of Maekawa's algorithm[6]. He mentioned that when a process may belong to more than one group, the process must identify one of the groups it belongs when it wishes to enter CS(Critical Section). However, his solution didn't provide mechanism of identifying a group which maximizes the possibility to enter CS. In this paper, we provide a mechanism for identifying that each process belongs to which group.