• Journal of the Korean Institute of Telematics and Electronics
• /
• v.25 no.12
• /
• pp.1663-1668
• /
• 1988

Ohmic contact process for the fabrication of GaAs integrated circuits is very important. Specific contact resistivities, assuming Rsm=Rs, were measured after the rapid and the conventional alloying process, respectively. The results show that the characteristics of ohmic contact through the rapid alloying process is much better (Apc=1.3~3.3x10**-7 \ulcorner-(m\ulcorner. This is probably due to intensive and compound energy densities during the rapid alloying process. New analysis method of TLM patterns viz. measurements of normlaized specific contact resistivities are proposed to reduce measurement errors that could occur when measuring the small contact end resistances. The adoption of rapid alloying process for the mass production of GaAs integrated circuits could greatly reduce the total processig time.

• Journal of the Korean Society for Precision Engineering
• /
• v.17 no.11
• /
• pp.213-219
• /
• 2000

A impeller hub is usually made through three forging processes : forward extrustion, upsetting and finishing. The finishing process is closed die forging in which the load increases abruptly at the final stage, resulting in underfilling in the finished product due to insufficient load capacity of the press. In this study, the rigid-plastic finite element analysis was applied to the impeller hub forging process in order to optimize process and to estimate required load. As a result, two kind of improvements for the process were suggested to reduce the load requirement in the finishing process.

• Journal of Internet Computing and Services
• /
• v.20 no.1
• /
• pp.125-133
• /
• 2019

Company A should maintain myriad conversion tools for the purpose of making a geometric compilation of navigation maps. Company A is already using complex compilation tools, which are tailored to geographical areas and various GPS models. However, due to frequent requirement and personnel changes, there is an endless challenge for perfect tool configuration and multiple map consolidation. To solve this problem, Company A launched a process automation project using Graphviz, which is an open source workflow graph visualization software. Before implementation, they had to document their current map compilation processes and then match it with the applicable conversion tool. For effective representation of process controls, a new graphical process notation is designed, i.e. Y Block diagram. The authors will compare Y Block diagram with other process notations and explain why Y Block diagram is more useful for tool based business processes such as digital map generation processes.

• Current Applied Physics
• /
• v.18 no.11
• /
• pp.1447-1450
• /
• 2018

The electron spin resonance (ESR) detects point defect of the In-Ga-Zn oxide (IGZO) like singly ionized oxygen vacancies and excess oxygen, and get spin density as a parameter of defect state. So, we demonstrated the spin density measurement of the IGZO film with various deposition conditions and it has linear relationship. Moreover, we matched the spin density with the total BTS and the threshold voltage ($V_{th}$) distribution of the IGZO thin film transistors. The total BTS ${\Delta}V_{th}$ and the $V_{th}$ distribution were degraded due to the spin density increases. The spin density is the useful indicator to predict $V_{th}$ instability of IGZO TFTs.

• Journal of the Korean Society of Systems Engineering
• /
• v.16 no.2
• /
• pp.141-147
• /
• 2020

Due to the nature of the long-term project of a Railway business, Many problems have been arisen in the process of delivering products or systems verified by suppliers to the customer's operation site. Unexpectedly, it is often necessary for the verified products to store intermediately at the supplier's site for a variety of reasons, such as delays in business and delays in civil engineering, at the time of sending them to the customer's operation site. In this study, the intermediate storage process for finding and solving problems related to intermediate storage was presented focusing on the Rolling Stock of Railway System by reference to ISO/IEC/IEEE 15288:2015. A suitable intermediate storage process based on the developed product or system's characteristics will allow the verified products or systems to be placed on the customer's operation site and to meet the customer's product or system requirements.

• Journal of Hospice and Palliative Care
• /
• v.24 no.1
• /
• pp.56-65
• /
• 2021

Purpose: Nurses' acceptance of patient deaths enables them to practice holistic end-of-life care and pursue positive living. The place where most deaths occur in Korea has changed from home to medical institutions, making it necessary to understand the process through which nurses who practice end-of-life care accept patient deaths. This study aimed to obtain insight into nurses' experiences of accepting patient deaths and to develop a practical theory regarding the context of this process. Methods: This qualitative study investigated nurses' process of acceptance of patient deaths based on grounded theory. Results: A core category of this process was found to be "grieving over dying", which consisted of the following steps: "being close by", "being attentive", "acknowledging together", and "accompanying." Conclusion: This study established that nurses' attentiveness toward dying people is due to their grief over patient deaths, and clarified Korean nurses' process of accepting patient deaths and its related factors.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.21 no.7
• /
• pp.1-9
• /
• 2022

Peeling and dimensional deformation that occur during a manufacturing process are accompanied by an increase in the manufacturing cost and production time caused by manufacturing defects. In order to solve this problem, it is essential to predict risk factors at the design stage through computational analysis of the additive manufacturing process and to control shape distortion due to residual stress. In this study, the dimensional characteristics were improved by applying the distortion compensation design through computational analysis to minimize the distortion occurring in the DMLS(Direct Metal Laser Sintering) method of the metal additive manufacturing process.

• Journal of the Korean Society for Precision Engineering
• /
• v.13 no.10
• /
• pp.130-138
• /
• 1996

In general, the scattler is observed in fatigue test data due to the nonhomogeneity of a material. Consequently. It is necessary to use the statistical method to describe the fatigue crack growth process precisely. Bogdanoff and Kozin suggested and developed the B-model which is the probabilistic models of cumulative damage using the Markov process in order to describe the damage process. But the B-model uses only constant probability ratior(r), so it is not consistent with the actual damage process. In this study, the r-decreasing model using a monotonic decreasing function is introduced to improve the B-model. To verify the model, thest data of fatigue crack growth of A12024-T351 and A17075-T651 are used. Compared with the empirical distribution of test data, the distribution from the r-decreasing model is satisfactory and damage process is well described from the probabilistic and physical viewpoint.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2021.05a
• /
• pp.289-290
• /
• 2021

The PC system has advantages in terms of project management, such as shortening the construction period and reducing costs. However, it is difficult to activate the technology due to insufficient application of the technology. Therefore, there is a need for a strategy to expand and activate the PC system. This study is a basic research for PC construction project management, and its purpose is to derive the entire construction process from factory production of PC components to on-site construction. In this study, the construction process of the PC system was derived through literature review, and the main matters for the construction process management of PC system were confirmed in the analysis process. In the future, the results of this study are expected to be used as basic data for research for PC project management, such as deriving construction classification and calculating construction periods.

• International conference on construction engineering and project management
• /
• 2015.10a
• /
• pp.28-29
• /
• 2015

The tire production facility is a large-scale construction with the complexity of a manufacturing process. The process utilities should be wide-ranging as an effective arrangement of them is highly important. All the necessary information should be clarified together with the manufacturer at the basic planning stage, and this design should be developed to comply with the local culture and regulations. It is important to carry out more advanced engineering in terms of process, cost and quality, even if it is difficult to standardize due to the cultural and geographical conditions and regulations. The key point is to reflect all the given conditions and make a clear design during the design stage, to eliminate the problems after the construction has begun. Another key point is the delivery system, which must be totally managed from the initial design stage until the construction stage by proven companies. Flexibility, quick action, and single responsibility will be the fundamental features in all the steps of the project.