• Journal of the Korea Safety Management & Science
• /
• v.17 no.2
• /
• pp.215-228
• /
• 2015

A creative innovation and an innovative problem-solving of industrial companies can be achieved by overcoming the challenges of technical and physical contradictions. The approaches to address conflicting and paradoxical problems, such as technical and physical contradictions have a crucial role in advancing the quality assessment for manufacturer and service provider. The term, technical contradiction, depicts the state that improvement of one ends of IFR (Ideal Final Result) leads to unfavorable condition of the other ends, and results in conflicting problem. Another type of contradictions that's discussed in this study is a physical contradiction which is due to two mutually opposing states of the means of ends, and gives paradoxical situation. By integrating the means-ends chain perspectives, the physical contradiction that is a specifically root-causes, "means", can be initially addressed to resolve the downstream problem of technical contradiction which represents a general and abstract goals, "ends". This research suggests IFR resolution processes to handle both physical contradiction of means and technical contradiction of ends by employing causal relationship with IFR, effects and causes. In summary, the study represents three major processes that resolve such contradictions are demonstrated as follows: 1) Derivation of causal and hierarchical relationship among IFR, ends and means by considering CAED (Cause-And-Effect Diagram) and LT (Logic Tree). 2) Identification of causal relationship between physical contradiction and technical contradiction by using TPCT (TRIZ Physical Contradiction Tree) and TCD (Technical Contradiction Diagram). 3) Application of integrated TRIZ principles by classifying 40 inventive principles into 4 general conditions of the separation principle of mutually opposite states in space, in time, based on conditions, and between the parts and the whole. In order to validate the proof of proposed IFR resolution processes, the analysis of the TRIZ case studies from National Quality Circle Contest in the years, 2011 to 2014 have been proposed. The suggested guidelines that are built based on TRIZ principles can uniquely enhance the process of quality innovation and assessment for quality practitioners.

• Journal of Korean Society for Quality Management
• /
• v.46 no.3
• /
• pp.539-550
• /
• 2018

Purpose: The purpose of this study was to find meaningful patient groups of disease using foreign patients data and analyze implemented test of the patient groups. Methods: The data was collected by foreign patients' EMR data of K university hospital. The author proposed tree-form patients' characteristic diagram through statistical methods that association rule, proportion test, clustering using prescription information and questionnaire information. Results: This study's analysis process was applied high blood data and diabetes data. Analysis showed other characteristic of meaningful patient groups in high blood and diabetes. In high blood, test implementation rate of patient group showed the differences. And in diabetes, test implementation rate of patient group and implemented test list showed differences. Conclusion: The result of this study can play a role as basic data that can be clinical testing standard in preventive aspect. Eventually, 5 dimensions of SERVQUAL will be improved by this study's process.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.27 no.6
• /
• pp.1467-1482
• /
• 2017

Recently, Interests on The Fourth Industrial Revolution has been increased. In the manufacturing sector, the introduction of Smart Factory, which automates and intelligent all stages of manufacturing based on Cyber Physical System (CPS) technology, is spreading. The complexity and uncertainty of smart factories are likely to cause unexpected problems, which can lead to manufacturing process interruptions, malfunctions, and leakage of important information to the enterprise. It is emphasized that there is a need to perform systematic management by analyzing the threats to the Smart Factory. Therefore, this paper systematically identifies the threats using the STRIDE threat modeling technique using the data flow diagram of the overall production process procedure of Smart Factory. Then, using the Attack Tree, we analyze the risks and ultimately derive a checklist. The checklist provides quantitative data that can be used for future safety verification and security guideline production of Smart Factory.

• Journal of the Korean Society for Precision Engineering
• /
• v.17 no.2
• /
• pp.176-184
• /
• 2000

Possible representation methods for the product structure have been compared and analyzed to determine optimal disassembly path of a product. Petri net is selected as the most optimal method to represent disassembly path of the product. In this method, a reachability tree for the product is generated and disassembly time for each path is calculated. A path with the smallest disassembly time is selected as the optimal path. A software far DPN(Disassembly Petri Net) has been developed and applied to search the optimal disassembly path for a ballpoint pen disassembly process as an example.

• Transactions of the Korean hydrogen and new energy society
• /
• v.31 no.1
• /
• pp.73-81
• /
• 2020

For the fault tree analysis (FTA) analysis of the packaged hydrogen filling station, the composition of the charging station was analyzed and the fault tree (FT) diagram was prepared. FT diagrams were created by dividing the causes of events into external factors and internal factors with the hydrogen event as the top event. The external factors include the effects of major disasters caused by natural disasters and external factors as OR gates. Internal factors are divided into tube tailer, compressor & storage tank, and dispenser, which are composed of mistakes in operation process and causes of accidents caused by parts leakage. In this study, the purpose was to improve the hydrogen station. The subjects of this study were domestic packaged hydrogen stations and FTA study was conducted based on the previous studies, failure mode & effect analysis (FMEA) and hazard & operability study (HAZOP). Top event as a hydrogen leaking event and constructed the flow of events based on the previous study. Refer to "Off shore and onshore reliability data 6th edition", "European Industry Reliability Data Bank", technique for human error rate prediction (THERP) for reliability data. We hope that this study will help to improve the safety and activation of the hydrogen station.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.45 no.2
• /
• pp.11-22
• /
• 2017

To successfully create a low-carbon landscape in order to become a low-carbon city, it is necessary to understand the dynamics of artificial greening's resources on a multi-scale. Additionally, the effects of carbon storage should be quantitatively evaluated. The purpose of this study is to simulate and evaluate the changes in carbon storages of artificial ground trees using system dynamics throughout a long-term period. The process consisted of analyzing the dynamics of the multi-scale carbon cycle by using a casual loop diagram as well as simulating carbon storage changes in the green roof of the Gangnam-gu office building in 2008, 2018, 2028, and 2038. Results of the study are as follows. First, the causal loop diagram representing the relationship between the carbon storage of the artificial ground trees and the urban carbon cycle demonstrates that the carbon storage of the trees possess mutual cross-scale dynamics. Second, the main variables for the simulation model collected 'Biomass,' 'Carbon storage,' 'Dead organic matter,' and 'Carbon absorption,'and validated a high coefficient of determination, the value being ($R^2$=0.725, p<0.05). Third, as a result of the simulation model, we found that the variation in ranking of tree species was changing over time. This study also suggested the specific species of tree-such as Acer palmatum var. amoenum, Pinus densiflora, and Betula platyphylla-are used to improve the carbon storage in the green roof of the Gangnam-gu office building. This study can help contribute to developing quantitative and scientific criteria when designing, managing, and developing programs on low-carbon landscapes.

• Transactions of the Korean hydrogen and new energy society
• /
• v.25 no.6
• /
• pp.609-619
• /
• 2014

In the present study, the frequency of the undesired accident was estimated for a quantitative risk assessment of a large-scale hydrogen liquefaction plant. As a representative example, the hydrogen liquefaction plant located in Ingolstadt, Germany was chosen. From the analysis of the liquefaction process and operating conditions, it was found that a $LH_2$ storage tank was one of the most dangerous facilities. Based on the accident scenarios, frequencies of possible accidents were quantitatively evaluated by using both fault tree analysis and event tree analysis. The overall expected frequency of the loss containment of hydrogen from the $LH_2$ storage tank was $6.83{\times}10^{-1}$times/yr (once per 1.5 years). It showed that only 0.1% of the hydrogen release from the $LH_2$ storage tank occurred instantaneously. Also, the incident outcome frequencies were calculated by multiplying the expected frequencies with the conditional probabilities resulting from the event tree diagram for hydrogen release. The results showed that most of the incident outcomes were dominated by fire, which was 71.8% of the entire accident outcome. The rest of the accident (about 27.7%) might have no effect to the population.

• Journal of Applied Reliability
• /
• v.17 no.1
• /
• pp.28-37
• /
• 2017

Purpose: This paper proposes a procedure that may infer and identify interaction failures in a module. Methods: In design FMEA, we defined an interaction model between components and proposed a method for selecting a single component by using the standard specification classification table and four methods for choosing the related components. We also introduced the function tree for function and requirement characteristic analysis and proposed utilization of standard stress lists and 1st and 2nd stress analysis tables to determine the effect the stress analysis has on interactions. Finally, the interaction mechanism diagram was proposed and used to infer the failure mechanism. Process FMEA also established procedures in a similar way. Results: We established a procedure for predicting the failure mode due to interaction between components based on Company A's multi-step FMEA procedure. Conclusion: By applying the proposed interaction FMEA procedure to the development model, we were able to confirm the effect of the new derivation on the failure mode of interaction, which was not predicted by the existing FMEA.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2009.11a
• /
• pp.253-256
• /
• 2009

To the success of the megaproject including various and complex facilities, it is needed to establish a database system. Developments in data collection, storage and extracting technology have enabled iPMIS to manage various and complex information about cost and time. Especially, when we consider that both the go and no go decision in feasibility, Cost is an important and clear criteria in megaproject. Thus, Cost data modeling is the basis of the system and is necessary process. This research is focus on the structure and definition about CBS data which is collected from sites. We used four tools which are Function Analysis in VE, Casual loop Diagram in System Dynamics, Decision Tree in Data-mining, and Normalization in SQL to identify its cause and effect relationship on CBS data. Cost data modeling provide iPMIS with helpful guideline.

• Korean System Dynamics Review
• /
• v.12 no.4
• /
• pp.63-92
• /
• 2011

The purpose of this paper is to investigate a possibility of applying multimethodological approach for solving a dilemma. The motivation of this attempt is that the two different approaches, the system dynamics and the theory of constraints, resemble each other in having mental models for describing the target system and using graphic tools for representing those mental models. After a brief discussion on the comparison of the two approaches, a combined method applying to the problem of dilemma is suggested. For an experimental example, the proposed approach is applied to the sales and finance conflict on an inventory issue. The study shows that the suggested approach is able to complement each other's drawbacks. Especially constructing a stock-and-flow model and implementing a computer simulation would be very useful for quantifying the system's behavior which is hardly tracked down when applying the theory of constraints alone.