• Journal of Magnetics
• /
• v.22 no.2
• /
• pp.344-351
• /
• 2017

Wireless magnet pumps are used in medical applications and are particularly useful as artificial heart ventricular assist devices (VADs). To investigate wireless operation of magnetic pumps, we fabricated three types of magnetic impellers using bonded magnets by blending magnetic powders of SmFeN, NdFeB, and Sr-ferrite. We investigated the magnetic properties of the fabricated magnetic impellers, which are driven by the application of magnetic coupling with an external driving magnet or external coil system, without a driving motor, shaft, or mechanical bearings. The use of wireless magnetic pumps is therefore not complicated by critical issues of size, heat, and vibration, which are very important issues for blood pumps. The magnetic properties of the impellers, such as their rotational speed, driving torque and hydrodynamic performance, determine their wireless driving ranges. We conducted performance evaluations of the impeller's magnetic wireless manipulation, heat, and vibration. In addition, we carried out an animal test to confirm the suitability of the wireless magnetic pumps for use as biventricular assist devices (BiVADs).

• Journal of the Korea Safety Management & Science
• /
• v.13 no.1
• /
• pp.31-39
• /
• 2011

In this study, supervision resides fire mission against problems associated with case studies and surveys done through the side of the field work, technical personnel, fire management, including fire code aspects classified into three kinds of items dealt with the issue. Started at the scene of the problem in terms of performance, the issue of the construction process, mainly dealt with the issue at the time of completion. Fire management side, supervisor of technical personnel, human resources management issues, contract issues, fire code level, the frequent revisions of fire regulations, supervision, processing delays of the resulting report, the problem resides with the expansion of Fire Supervision target was mentioned. Finally, the target for each hierarchical supervision, and resident supervisor of the need for supervision of work performance test was carried out by the correlation.

• Journal of the Korea Society of Computer and Information
• /
• v.21 no.1
• /
• pp.17-24
• /
• 2016

In this paper, we introduce indoor localization technologies categorizing them into ON/OFF switch and senor based, wireless communication based, and image based technologies. Then we describe several representative techniques for each of them, emphasizing their strengths and weaknesses. We define important performance issues for indoor localization technologies and analyze recent technologies according to the performance issues. Our analyses show that ON/OFF switch based technologies are difficult to install, but accurate and not limited by light. Wireless communication technologies are not limited by light nor distance (space) and do not need additional device. Image based technologies do not need additional device but are limited by light, and their accuracies are affected by light. We believe that this paper provide wise view and necessary information for recent indoor localization technologies.

• Industrial Engineering and Management Systems
• /
• v.7 no.1
• /
• pp.78-89
• /
• 2008

The need for holistic modeling efforts for returns that capture the extended closed loop supply chain (CLSC) system at strategic as well as operational level has been clearly recognized by the industry and academia. Strategic decision-makers need comprehensive models that can guide them in efficient decision-making to increase the profitability of the entire forward and return chain. Therefore, determination of a near optimal design configuration, which includes the environmental, economical and technological capability factors, is important in strategic decision-making effort that affect the profitability of the closed loop supply chain. In this paper, we adopted an improved system dynamics methodology to tackle strategic issues that affect various performance measures, like market, time/cost, environment etc., for closed loop supply chains. After studying real life implementation issues in CLSC design, we presented guidelines for the PBM (Participative Business Modeling) methodology and presented its extension for the strategic dynamic system modeling of return chains. Finally, we demonstrated the measurement of operational performance by extending SD (system dynamic) application to closed loop supply chain management.

• Journal of the Institute of Convergence Signal Processing
• /
• v.12 no.2
• /
• pp.119-127
• /
• 2011

The paper surveys various analytical models for IEEE 802.11 medium access control protocols and critically discusses recent issues developing in wireless mobile ad hoc networks and their MACs. The surveyed MAC protocols include the standard IEEE 802.11 MAC suites such as IEEE 802.11 DCF, IEEE 802.11 PCF, IEEE 802.11e EDCA, and IEEE 802.11 ad hoc mode; and also the newer, de facto MAC protocols. We study the analytic models of the standard MAC suites followed by the newer analytic models that have been published in recent years. Also, the paper tries to include most of current literatures discussing analytic modeling of MAC in conjunction to some critical issues such as contention among ad hoc nodes, hidden terminal problems, and real-time service support.

• International conference on construction engineering and project management
• /
• 2009.05a
• /
• pp.774-780
• /
• 2009

Simulation is becoming increasingly popular in construction for training, planning and for assessment of projects. There are, however, significant problems inherent in simulating construction which are not common to other simulations. This paper describes the development and use of computer-based game for teaching and learning of some aspects of construction project management. It is concerned with the development of a model used to simulate the construction of a rock- and clay-fill dam. It includes detailed physical modelling of the performance of individual pieces of equipment and their interaction with the ground, the geography of the project and the weather in which the equipment operates. The behaviour of all of the individual pieces of equipment when acting as fleets is also discussed. The paper also describes the modelling issues of non-technical aspects of earthmoving operations. These include environmental impact, safety, quality and risks. The problems of integrating these with the physics-based models of the equipment performance are discussed. The paper also draws on real experience of using the game in classes in three universities in different countries.

• International conference on construction engineering and project management
• /
• 2005.10a
• /
• pp.469-473
• /
• 2005

Contract design plays a key role in the life cycle of BOT project. All project management activities and operation processes are arranged in consistence with the document of BOT contract which the public sector ensures that the respective roles and responsibilities set out in the contract are fully understood and fulfilled to the contracted performance criteria. With limited theories to deal with some fundamental issues of BOT contract design, we try to collect data from case studies and formulate several practical principles. The conclusions presented in this paper are analyzed from two cases, one is based on an early case in the United Kingdom, and the other based on the Taiwan High Speed Railway case. The purpose of this paper is not about covering all legal issues about BOT contract design, but rather, our work provides common considerations applicable to the contract parties of a broad range of BOT contracts. The results in this paper shall propose some fundamental principles of the BOT contract design.

• Journal of Agricultural Extension & Community Development
• /
• v.30 no.4
• /
• pp.213-227
• /
• 2023

This paper aims to examine the farmers' perceptions of the importance and feasibility of climate change awareness and adaptive measures in agriculture, utilizing paired sample t-tests and Importance-Performance Analysis (IPA). Significant differences were found in farmers' views on the importance and urgency of climate change issues, with specific factors standing out. The IPA analysis identified key issues requiring sustained attention, including climate change magnitude, extreme weather events, livestock damage scale, pest fluctuations, and variability in flowering periods. Additionally, the study revealed significant disparities in farmers' perceptions of the importance and feasibility of adaptive measures, except for specific items related to heat indices.

• Information Systems Review
• /
• v.9 no.1
• /
• pp.139-160
• /
• 2007

Our study focuses on empirical findings of the critical factors which influence the performance of ERP system in business. The study is mainly interested in examining the influence of the characteristics of late process of adopting ERP called "Go-Live" phase with the critical issues like customizing, transformational process of standardization, phased implementation, concurrent operation and use with the current systems on users' ERP satisfaction. The analyses of the data conducted thru moderated regression analysis and subgroup analysis. Using moderated regression analysis, we first examined the effect of moderator variables like customizing, process standardization, sequential use, concurrent use with the current systems. And then, using subgroup analysis is to verify directions of the moderator effects. Having knowledge on the characteristics of ERP Go-Live process can lead to success of ERP system in business. Our results can be beneficial to those organizations who want to adopt and maintain ERP system effectively.

• Proceedings of the Korean Nuclear Society Conference
• /
• 2003.10a
• /
• pp.290.1-290.1
• /
• 2003