• Nuclear Engineering and Technology
• /
• 제52권3호
• /
• pp.560-567
• /
• 2020

The complexity of safety critical systems of Nuclear Power Plant continues to increase rapidly due its transition from analog to digital systems. It has thus become progressively more imperative to model these systems prior to their implementation in order to meet the high performance, safety and reliability requirements. Timed Petri Nets (TPNs) have been widely used to model such systems for non-functional analysis. The paper presents a novel methodology for the analysis of the performance metrics using PN modeling. The paper uses the isomorphism property of the TPNs and the Markov chains for the performance analysis of the safety critical systems. The presented methodology has been validated on a Shutdown System of a Nuclear Power Plant.

• 대한산업공학회지
• /
• 제39권4호
• /
• pp.260-270
• /
• 2013

This paper proposes a strategic portfolio model for managing performance of online games. The portfolio matrix is composed of two dimensions: financial performance and non-financial performance. Financial performance is measured by the conventional measure, average revenue per user (ARPU). In terms of non-financial performance, five non-financial key performance indicators (KPIs) that have been widely used in the online game industry are utilized: RU (Register User), VU (Visiting User), TS (Time Spent), ACU (Average Current User), MCU (Maximum Current User). Data envelopment analysis (DEA) is then employed to produce a single performance measure aggregating the five KPIs. DEA is a linear programming model for measuring the relative efficiency of decision making unit (DMUs) with multiple inputs and outputs. This study employs DEA as a tool for multiple criteria decision making (MCDM), in particular, the pure output model without inputs. Combining the two types of performance produces the online game portfolio matrix with four quadrants: Dark Horse, Stop Loss, Jack Pot, Luxury Goods. A case study of 39 online games provided by company 'N' is provided. The proposed portfolio model is expected to be fruitfully used for strategic decision making of online game companies.

• Journal of Information Processing Systems
• /
• 제20권2호
• /
• pp.215-225
• /
• 2024

With the rapid development of Internet of Things (IoT) and big data technology, a large amount of data will be generated during the operation of related industries. How to classify the generated data accurately has become the core of research on data mining and processing in IoT industry chain. This study constructs a classification model of IoT industry chain based on improved random forest algorithm and text analysis, aiming to achieve efficient and accurate classification of IoT industry chain big data by improving traditional algorithms. The accuracy, precision, recall, and AUC value size of the traditional Random Forest algorithm and the algorithm used in the paper are compared on different datasets. The experimental results show that the algorithm model used in this paper has better performance on different datasets, and the accuracy and recall performance on four datasets are better than the traditional algorithm, and the accuracy performance on two datasets, P-I Diabetes and Loan Default, is better than the random forest model, and its final data classification results are better. Through the construction of this model, we can accurately classify the massive data generated in the IoT industry chain, thus providing more research value for the data mining and processing technology of the IoT industry chain.

• 한국컴퓨터정보학회논문지
• /
• 제26권2호
• /
• pp.201-211
• /
• 2021

본 연구는 물류기업이 블록체인기술을 활용하는 경우에 다른 비즈니스 모델을 가질 것이라고 보고 이러한 비즈니스 모델을 파악하는 것을 연구목적으로 한다. 이와 더불어 블록체인기술을 활용하는 물류기업들의 흡수역량과 성과의 차이를 파악하고자 한다. 이러한 연구목적을 달성하기 위해 본 연구에서는 물류기업에 대한 설문조사를 실시하였고 수집된 자료를 분석하였다. 비즈니스 모델을 파악하기 위하여 군집분석을 실시하였고 군집분석의 유의성을 파악하기 위하여 분산분석을 실시하였다. 군집분석을 통해 파악된 비즈니스 모델에 따라 흡수역량과 성과의 차이를 분석하였다. 추가적으로 흡수역량과 성과 차이를 파악하기 위해 PLS 분석을 실시하였다. 결과를 보면 물류기업들은 블록체인기술을 채택함에 있어 다른 비즈니스 모델의 유형을 가지고 있다는 것을 알 수 있었다. 비즈니스 모델의 발전정도가 높은 기업군들이 흡수역량과 성과 수준에서 높은 결과를 나타내었다.

• 지식경영연구
• /
• 제11권1호
• /
• pp.83-96
• /
• 2010

In this study, the effect of firm's patent competency on the their management performance was analysed. The number of patents granted to Korean firms, patent grade score as of the firm's patent competence were considered in the perspectives of patent volume and patent value respectively. Specially the analysis were implemented focusing on the high performance venture ranked 200th in Korea. The patent source data were from the Korean Intellectual Property Office, Korean Credit Evaluation Information Company, and the Patent Evaluation System of KIPO and KIPA. And the year sales and net profit volume as of the firm's management performance data from the KIS. Management performance data are consisted of the mean sales, net profit and ROI during the 4 years from FY2005 to FY2008. Major results are as follows. The regression model were proved significantly that the year sales volume and net profit are effected by the number of patents and patent grade score. But the model including the ROI were shown not significantly. So it can be concluded that patent volume and patent value are the important factors on firm's financial performance as of the year sales volume and net profit. Also the regression model including the control variables, firm's number of employee and business year, the number of patents and patent grade score are the significant factors on firms performance. And regression coefficients of patent value model were higher than these of patent volume model. So it can be recognized that patent value of firms' patent competency are more important factor than the patent volume.

• 무역상무연구
• /
• 제37권
• /
• pp.361-389
• /
• 2008

The purpose of this study is to detect the factors which have an effect on transformation level and performance and to provide the ways of successful transformation and vitalization from OEM to ODM. This study was proceeded by an empirical analysis. A model and hypotheses were set up and they were verified through the empirical analysis. Those factors were divided into four, inner company factors, strategic factors, core competence factors and purchase determining factors. In the result of the model suitability analysis on the study model of relationship among 'influencing factors of ODM transformation - ODM transformation level-export performance', every factors, $X^2=912.067$, DF=261, p value=0.000, GFI=0.737, AGFI=0.620, NFI=0.786, IFI=0.837, CFI=0.834, Q value=3.495 were rather insufficient to be a good model, but they were good enough for the general analysis. Taking these accounts into consideration, this study suggests the following implications. First, making a plan and setting up strategies in advance are required. Second, financial plan has to be prepared. Third, trends in global markets have to be analyzed. Fourth, companies have to focus on developing new materials and products through R&D. Fifth, quality competitiveness and quality control systems are required.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 1999년도 하계종합학술대회 논문집
• /
• pp.683-686
• /
• 1999

In this paper, we develop an active sonar signal synthesis model to analyze the detection performance of active sonar systems in a shallow water environment. Using this model, we synthesize the return signal of a bistatic sonar system at a typical operating frequency. This signal can be used to test proper active sonar signal processing techniques for real applications.

• 한국자동차공학회논문집
• /
• 제7권6호
• /
• pp.144-155
• /
• 1999

An occupant analysis code SAFE (Safety Analysis For occupant crash Environment) is utilized to simulate and improve the crash performance of an energy absorbing steering system. The safety standard FMVSS 203 is simulated and used for design evaluations . Segments and contact elliposids are utilized to model the bod blocks and the components of the steering system with SAFE. Spring-damper elements and force-deflection characteristics are utilized to model the energy absorbing components such as the plate and the polyacetal molding. The plate absorbs the impact energy through tensile deformation . Whereas, the polyacetal molding absorbs the impact energy through compression. the body block test is carried out to validate tie simulation model, and real component tests are performed to extract the force-deflection curves . After the model is validated , the parameter study is carried out to evaluate the crash performance of the energy absorbing components. A performance measure is defined for the parameter study. Using the results of the parameter study and managing the orthogonal arrays, optimum design values of energy absorbing components are determined to minize the occupant injury.

• 한국의류학회지
• /
• 제16권4호
• /
• pp.443-455
• /
• 1992

The purpose of this study is to verify the theoretical model on the clothing satisfaction. Research problems are as following; 1. To identify a causal model on the clothing satisfaction. 2. To examine the causal model by the brand levels. 3. To examine the causal model by the consumer characteristics. The empirical study of the above research problems is carried out by the longitudinal survey. The subjects selected for the final analysis are 362 women living in Seoul and Pusan. The results of our analysis are as following; 1. The main causal course of the clothing satisfaction is that the brand level and the consumer expectation $\rightarrow$ the expectation $\rightarrow$ the perceived performance ($\rightarrow$ the disconfirmation) $\rightarrow$ the clothing satisfaction. Those relevant variables explain $70\%$ of the clothing satisfac-tion variance. Especially, the influence of the perceived performance appears to be greater than that of the disconfirmation. 2. According to our analysis, the expectation influences the clothing satisfaction indirectly through the perceived performance. Especially, the normative expectation exhibits the contrast effect on the disconfirmation, while the predictive expectation exhibits the assimilation effect on the perceived performance. 3. The clothing satisfaction model differs by the brand levels (high price brand vs. moderate price brand) and by the consumer involvement levels (high involvement vs. low involvement). The relevant variables explain $65\%$ of the clothing satisfaction variance in the high price brand, while they explain $77\%$ in the moderate price brand. In the high involvement group, the relevant variables explain $78\%$ of the clothing satisfaction variance and $60\%$ in the low involvement group. In both involvement groups, the most critical direct variable is the perceived perfor-mance. In conclusion, we find that the clothing satisfaction can be explained by three constructs, the expectation, the perceived performance and the disconfirmation. The hypothesis that the two dimensions of the expectation explain the clothing satisfaction better is empirically supported in our study. Finally, we find that the clothing satisfaction models differ between two brand levels and consumer involvement levels.

• Nuclear Engineering and Technology
• /
• 제41권6호
• /
• pp.785-796
• /
• 2009

A KALIMER-600 concept which is a type of sodium-cooled fast reactor, has been developed at KAERI. It uses sodium as a primary coolant and is a pool-type reactor to enhance safety. Also, a supercritical carbon dioxide ($CO_2$) Brayton cycle is considered as an alternative to an energy conversion system to eliminate the sodium water reaction and to improve efficiency. In this study, a simplified model for analyzing the thermodynamic performance of the KALIMER-600 coupled with a supercritical $CO_2$ Brayton cycle was developed. To develop the analysis model, a commercial modular modeling system (MMS) was adopted as a base engine, which was developed by nHance Technology in USA. It has a convenient graphical user interface and many component modules to model the plant. A new user library for thermodynamic properties of sodium and supercritical $CO_2$ was developed and attached to the MMS. In addition, some component modules in the MMS were modified to be appropriate for analysis of the KALIMER-600 coupled with the supercritical $CO_2$ cycle. Then, a simplified performance analysis code was developed by modeling the KALIMER-600 plant with the modified MMS. After evaluating the developed code with each component data and a steady state of the plant, a simple power reduction and recovery event was evaluated. The results showed an achievable capability for a performance analysis code. The developed code will be used to develop the operational strategy and some control logics for the operation of the KALIMER-600 with a supercritical $CO_2$ Brayton cycle after further studies of analyzing various operational events.