• Journal of the Korean Society for Railway
• /
• v.10 no.4
• /
• pp.438-443
• /
• 2007

This paper proposes an integrated SE process for the development of railway systems with safety assessment included. Although the safety assessment process must be performed with SE process properly with good coordination, the interfaces between the two processes have not been clear. Thus, in many of safety critical system developments in Korea, it is difficult to assess safety in proper development phase. The process model proposed in this paper is based on both the concept of system life cycle and the repetitive use of SE process. In each of development phases, appropriate safety assessment methods are described. Also the evaluation of the integrated system incorporating safety factors is described. The resultant process model is expressed by the Enhanced Functional Flow Block Diagram (EFFBD) using a CASE tool. The model also allows timeline analysis for identifying activity flow and data flow, resulting in the effective management of process. In conclusion, the integrated process enable both the SE process and safety assessment process to cooperate with each other from early development phase throughout the whole system life cycle.

• Advances in aircraft and spacecraft science
• /
• v.9 no.6
• /
• pp.493-506
• /
• 2022

The study presents the results of the research of heat and heat exchange processes on the heat-stressed elements of the structure of an advanced TsAGI descent vehicle. The studies were carried out using a mathematical model based on solving discrete analogs of continuum mechanics equations. Conclusions were drawn about the correctness of the model and the dependence of the intensity of heat and mass transfer processes on the most heat-stressed sections of the apparatus surface on its geometry and the catalytic activity of the surface.

• IE interfaces
• /
• v.4 no.1
• /
• pp.71-81
• /
• 1991

Presented in this paper is a systematic approach to "modeling and simulation' of flow lines in mass production systems, using a tire trimming line as an example. The "modeling phase" consists of 1) generation of alternative line configurations, 2) construction of a reference model for each alternative, and 3) formal description of the target system. ACD(Activity Cycle Diagrams) are employed as a tool for formal description. In the "simulation phase'. block diagram models (provided by the simulation language SIMAN) and the next event methodology(implemented in FORTRAN 77) are combined in order to fully describe the flow line behavior.

• Journal of Korean Institute of Industrial Engineers
• /
• v.23 no.4
• /
• pp.669-686
• /
• 1997

In this research, an object-oriented Petri net model for representing a flexible process plan is proposed, which is hierarchically multi-faceted for supporting planning, scheduling, and shop floor control functions. The multi-faceted process plan model consists of the following: a) an object model which represents on object-oriented data model, b) a static model which represents a process flow model with process alternatives, and c) a dynamic model which represents a process activity model with resources alternatives, of a flexible process plan. Petri nets allow the static and the dynamic process plan models to be represented in a unified formalism with an ease of model transformation. The multi-faceted process plan model suggested in this paper, is illustrated with a prismatic port in comprehensive detail.

• Knowledge Management Research
• /
• v.9 no.2
• /
• pp.169-191
• /
• 2008

Information technology instruments arc being rampantly used for knowledge management in companies. IT is used as an interplay tool to enhance the flow of knowledge and information between people. KMS, especially, supports the knowledge management process including sharing, creating, and using of knowledge within a company, and maximizes the value of knowledge resources within an organization. The purpose of this paper is to understand how IT is changing the knowledge management activity. through various examples based on exploratory research from MANDO, the Korean automotive parts manufacturer, and POSCO, the global leading steelmaker. The result shows that IT boosts communication skills, thus creates a mutual relationship outcome. In the same context, the process of knowledge conversion by Nonaka's SECI model simplifies to an Externalization-Internalization process. This process accelerates the birth of explicit knowledge and Socialization, supplements the Limitations of the creation of knowledge in the E-I cycle. The E of knowledge simultaneously promotes the I, and eventually brings an advanced learning skill. IT aids the E of knowledge and furthermore, I and E activity, through the knowledge sharing, brings vitality into an organization. The interplay stage for knowledge activity is to be reorganized to a cyber ba. Furthermore, IT will galvanize the formation of core knowledge through systemized acquisition, management of core knowledge and standardization of work.

• The Korean Journal of Physiology and Pharmacology
• /
• v.10 no.4
• /
• pp.181-186
• /
• 2006

This study was undertaken to evaluate whether peroxisome proliferator-activated-receptor-gamma $(PPAR-{\gamma})$ agonist-rosiglitazone (ROSI) induces postischemic functional recovery in Langendorf heart model. Hearts isolated from normal rats were subjected to 20 min of normoxia or 25 min zero-flow ischemia followed by 50 min reperfusion. In this acute protocol, ROSI $(20\;{\mu}g/ml)$ administered 10 min before ischemia had no effect on hemodynamic cardiac function, but had protective effect on lipid peroxidation in in vitro experiments. In chronic protocol in which ROSI was given by daily gavage (4 mg/kg) for three consecutive days, ROSI could not prevent the hemodynamic alteration on cardiac performance, but has protective effect on the activity of superoxide dismutase (SOD). There was no significant difference in the contents of reduced glutathione (GSH) and catalase activity between ischemia-reperfusion (IR) and ROSI treated IR hearts. Although ROSI had no effect on hemodynamic factor, it had effect on antioxidant activity. Our results indicate that ROSI provides partial beneficial effects by inhibiting lipid peroxidation and/or recovering normal level of SOD activity in the ischemic reperfused heart.

• International conference on construction engineering and project management
• /
• 2022.06a
• /
• pp.145-152
• /
• 2022

Recently, interest in the precast concrete (PC) construction method has been increasing. The PC construction process consists of i) design, ii) production, iii) transportation, and iv) installation. A PC field manager at the site submits a shipment request form to the factory one to three days before the installation of the PC component. Numerous matters should be considered in writing a shipment request form. Incorrect shipment request forms may cause standby resources, waste of resources, premature work conclusion, or excessive work. These issues can lead to an increase in construction costs, replanning of PC component installation, or rework. In order to prevent such problems, PC component installation should be simulated based on the shipment request form. Accordingly, this study aims to identify factors influencing the operability of shipment request forms for PC construction. To this end, this study derived factors influencing i) initiation of the activity, ii) addition or deletion of activities, and iii) an increase or decrease in the activity execution time. As a result, this study identified flow, the features of PC components, condition of PC components, unloading location, installation location, input equipment and labor, number of anchors, number of supports, weather, strike, and accident. Further studies should verify the factors derived in this study based on focus group interviews.

• Journal of Internet Computing and Services
• /
• v.20 no.3
• /
• pp.77-84
• /
• 2019

Workflow management system is a system that manages the workflow model which defines the process of work in reality. We can define the workflow process by sequencing jobs which is performed by the performers. Using the workflow management system, we can also analyze the flow of the process and revise it more efficiently. Many researches are focused on how to make the workflow process model more efficiently and manage it more easily. Recently, many researches use the workflow log files which are the execution history of the workflow process model performed by the workflow management system. Ourresearch group has many interests in making useful knowledge from the workflow event logs. In this paper we use XES log files because there are many data using this format. This papersuggests what are the cardinalities of the temporal workcases and how to get them from the workflow event logs. Cardinalities of the temporal workcases are the occurrence pattern of critical elements in the workflow process. We discover instance cardinalities, activity cardinalities and organizational resource cardinalities from several XES-based workflow event logs and visualize them. The instance cardinality defines the occurrence of the workflow process instances, the activity cardinality defines the occurrence of the activities and the organizational cardinality defines the occurrence of the organizational resources. From them, we expect to get many useful knowledge such as a patterns of the control flow of the process, frequently executed events, frequently working performer and etc. In further, we even expect to predict the original process model by only using the workflow event logs.

• Journal of the Korea Society for Simulation
• /
• v.6 no.1
• /
• pp.25-40
• /
• 1997

This study deals with an autonomous generation of simulation codes for the design of processes of c CIM system based on the concept of model transformation. We assume we have a functional model of an organization which is developed using the well-known IDEF0 methodology. Then, a modeling methodology, called PROWD(PRocess flOW Description), is suggested to develop the flow processes of the organization. To Derive simulation specifications for the transformed PROWD model, we define a module of a "unit system" for each activity of PROWD model. Then specifications for system entities and resources are derived from input/control/mechanism/output and entity flows of PROWD model. Entitiy queues are defined from the sates and events of unit systems. Finally, SIMAN model frame is generated from those specifications through a suggested algorithm. The implementability and validity of the proposed approach is tested by developing a prototype of a computer-assisted design system on the operation processes of FMS installed at SNU-ASRI (Seoul National University-Automation and Systems Research Institute).nstitute).

• YAKHAK HOEJI
• /
• v.45 no.1
• /
• pp.108-115
• /
• 2001

We have recently reported the development of a high efficiency expression vector, pCK, which can drive a high level of gene expression in mouse skeletal muscle. In this study, we tested the therapeutic potential of pCK expressing human VEGF165, pCK-VEGF in the rabbit ischemic hind limb model. To determine the optimal dose of plasmid DNA, various concentrations of pCK-CAT were injected into the muscle of a rabbit hind limb and the levels of CAT activity were determined. It was found that the expression level of the exogenously added gene became stable between 250 and 1,000 $\mu$g. Based on this result, we tested whether intramuscular transfer of 500$\mu$g of pCK-VEGF could actually modulate collateral vessel development in a rabbit ischemic hind limb model. It was found that relative to the control group injected with the pCK lacking the VEGF sequence, single intramuscular doses (500$\mu$g) of pCK-VEGF produced statistically significant augmentation of collateral vessels as determined by the angiographic vessel count, maximal blood flow by Doppler flowmeter and the number of capillaries by histology. These results suggest that a single 500$\mu$g-delivery of pCK-VEGF is potent enough to induce sufficient angiogenic activity and achieve therapeutic benefit on this rabbit model.