• Tuberculosis and Respiratory Diseases
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• v.79 no.4
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• pp.207-213
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• 2016

Chronic obstructive pulmonary disease (COPD) encompasses several clinical syndromes, most notably emphysema and chronic bronchitis. Most of the current treatments fail to attenuate severity and progression of the disease, thereby requiring better mechanistic understandings of pathogenesis to develop disease-modifying therapeutics. A number of theories on COPD pathogenesis have been promulgated wherein an increase in protease burden from chronic inflammation, exaggerated production of reactive oxygen species and the resulting oxidant injury, or superfluous cell death responses caused by enhanced cellular injury/damage were proposed as the culprit. These hypotheses are not mutually exclusive and together likely represent the multifaceted biological processes involved in COPD pathogenesis. Recent studies demonstrate that mitochondria are involved in innate immune signaling that plays important roles in cigarette smoke-induced inflammasome activation, pulmonary inflammation and tissue remodeling responses. These responses are reviewed herein and synthesized into a view of COPD pathogenesis whereby mitochondria play a central role.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.2
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• pp.275-284
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• 1997

Thermodynamic behavior of a composite system which is composed of two simple thermal subsystems with constant heat capacities is analyzed, and several thermodynamic phenomena are investigated. The changes of the states and the potential work of the composite system are shown as the interaction between the subsystems in the composite system. The potential work is defined as the possible maximum available work from the composite system, and it is a thermodynamic property of the composite system. The decrease of the potential work is the same as the available work output from the composite system in reversible processes. The dissipation of available work is directly connected to the generation of entropy. The concepts of exergy and internal energy can be explained as a special case of the potential work.

• Transactions of Materials Processing
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• v.9 no.3
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• pp.265-273
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• 2000

The conventional and new forging processes of the power steering worm blank are analyzed by the rigid-plastic finite element method. The conventional process contains three stages such as indentation, extrusion and upsetting, which was designed by a forming equipment expert. Process conditions such as reduction in area, semi-die angle and upsetting ratio are considered to prevent internal or geometrical defects. The results of simulation of the conventional forging process are summarized in terms of deformation patterns, load-stroke relationships and die pressures for each forming operation. Based on the simulation results of the current three-stage, the power steering worm blank forging process for improving the conventional process sequence is designed. Die pressures and forming loads of proposed process are within limit value which is proposed by experts and the proposed process is found to be proper for manufacturing the power steering worm blank.

• The Korean Journal of Ceramics
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• v.7 no.1
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• pp.41-44
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• 2001

A composite of $Ca_3$(PO$_4$)$_2$ and MgAl$_2$O$_4$ spinel is biologically active and has enduring strength. Its strength depends on the spinel phase. The flaws in the spinel depend on the grain size of the calcium phosphate phase and are not altered by dissolution. The calcium phosphate, ${\alpha}$ tri-calcium phosphate, controls the tissue response. Bone bonds to the implant. A design for a bone graft as a replacement for a section of the diaphysis of a canine femur provides for tensile, compressive, torsional and bending load; and for the physiological processes of bonding and remodeling. A bone plate, used to stabilize the implant at time of surgery was removed after about one year. Over seven years of service have been achieved without internal or external fixation.

• IE interfaces
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• v.23 no.2
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• pp.126-138
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• 2010

Marine equipment makers today face a multitude of challenges including the needs of an internal system for easy management of their business processes and a collaboration system to streamline communications with the parent company, increasing product complexity and heightened requirements for information technology. In this research, a BPM-ERP system called Biz $Tower^{(R)}$ was implemented based on cloud computing for especially, small and medium marine equipment makers to standardize and visualize the entire business process from order placement to release. This system also provides their parent company with visibility into the status of orders and user can easily access the system on the web at a low price through cloud computing service. Thus far, this paper demonstrates the applicability of Biz $Tower^{(R)}$ to improve management visibility, process performance, and collaboration with the parent company for small and medium marine equipment makers.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.7
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• pp.210-218
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• 1999

Sheet deposition type rapid prototyping system have many advantages : high build speed, low operating cost, large part size, no phase change, no need for support generation, and forth. However, those sheet deposition type rapid prototyping system require an additional post processing to remove excessive material attached to the part. This post processing is time consuming and labor intensive. Moreover, it is difficult for those system to fabricate parts with hollow cores and internal cavities. A new sheet deposition type rapid prototyping system that minimizes the post processing is proposed. The proposed system automatically removes excessive material in a peeling-off process between two cutting processes. In this way, the proposed system can reduce the post-processing time and cost as well as the limitation of the feasible geometric shapes in the conventional sheet deposition system.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2000.04a
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• pp.330-336
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• 2000

This paper discusses the potential of system dynamics modelling to support balanced scorecard. The balanced scorecard is a conceptual framework for translating an organisation's strategy into a set of performance indicators. These performance indicators are distributed across the 'classic'model's four perspective: Customers, Internal Business Processes, Financial, and Learning and Growth. This balanced scorecard, whilst having significant strength, suffers from the limitation of all performance indicator systems, namely that the interrelationships between indicators are overlooked and there is no way of taking into account the impact of delayed feedback which flows from introduction of new policy and legislative changes. System Dynamics is a methodology for understanding complex problems where there is dynamic behaviour and where feedback impacts significantly on system outcomes. System dynamics provides a rigorous basis for qualitative testing of the effects of performance indicators in complex environments such as health or social security. This can be supplemented with quantitative system dynamics simulation tools that further test the validity of indicators and the business rules implicit in them. System dynamics modelling has an important role to play in extending feedback cycle in performance measurements to a full systems approach.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.16 no.4
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• pp.41-48
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• 2008

Functional analysis of air transport mission is conducted to establish the performance requirements of the commercial transport designs. The analysis process begins by making a top-down analysis to the aircraft system level mission functions. Correctly interpreting the top-level performance requirements is the first step in designing and building an aircraft system. Each function and sub-function is allocated and examined to the aircraft level and flight operations phase to optimize the system performance and design requirements, such that these lower-level requirements can be traced back to the top-level requirements they are designed to fulfill. Special attention is given to making sure all interfaces, both internal and external, are addressed. The results are also in good resources of functional hazard assessment involved in certification processes.

• Structural Engineering and Mechanics
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• v.47 no.3
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• pp.307-329
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• 2013

The bending problem of Euler-Bernoulli discontinuous beams is dealt with, in which the discontinuities are due to the loads and eventually to essential constrains applied along the beam axis. In particular, the loads are modelled as random delta-correlated processes acting along the beam axis, while the ulterior eventual discontinuities are produced by the presence of external rollers applied along the beam axis. This kind of structural model can be considered in the static study of bridge beams. In the present work the exact expression of the response quantities are given in terms of means and variances, thanks to the use of the stochastic analysis rules and to the use of the generalized functions. The knowledge of the means and the variances of the internal forces implies the possibility of applying the reliability ${\beta}$-method for verifying the beam.

• Journal of the Korea Safety Management & Science
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• v.10 no.3
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• pp.183-191
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• 2008

Many companies desperately effort to find out more effective management method to survive in keen competition. Jack welch of past GE's CEO had said that an excellent result of today's GE management is thanks to Six sigma work. Many korean companies are introduced Six sigma method in their management since late 1993. Six sigma uses a set of strategies, statistics and methods to improve the processes we use to do everything from designing to manufacturing a product from marketing products and services to providing business information to our internal and external customers. The purpose of this study is to overcome these problems and to help make an important decision in establishing introduction strategy by abstracting the reasons and success factors and result indices which are important sources for introducing Six sigma management.