• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.10 no.11
• /
• pp.3354-3362
• /
• 2009

Recently, the potential of advanced studies is being highlighted that the networking activity of entrepreneurs of venture businesses influences successful foundation. Given this background, this study intends to make an exploratory study on the influence of self-efficacy of the entrepreneur's cognitive characteristic and patience with ambiguity of the psychological characteristic upon networking activity, and the components of networking activity upon entrepreneurial performance. It was tested with sample of responses to the questionnaires for 156 entrepreneurs of venture businesses which are under 3 years since they were founded. Findings of this study are as follows: First, the entrepreneur's self-efficacy was shown to have a significant effect on networking and entrepreneurial performance. Second, patience with ambiguity was shown not to have a significant effect on networking and entrepreneurial performance. Third, networking was shown to have an effect on entrepreneurial performance, and among the components of networking activity, network frequency and reliability were shown to significantly influence entrepreneurial performance, while network range was shown not to have a significant effect on it. Therefore, for performance improvement of start-up enterprises, rather self-efficacy of the entrepreneur's cognitive characteristic than the psychological characteristic seems more important. Also, with a practical suggestion that for the networking activity of entrepreneurs of venture businesses, network frequency and reliability may have a more critical effect rather on entrepreneurial performance than network range, the limitation and direction of this study are presented.

• The Journal of the Korea Contents Association
• /
• v.16 no.12
• /
• pp.551-561
• /
• 2016

A user influence discrimination scheme using big data from social networks is needed. In this thesis, we propose a user influence discrimination scheme considering reliability in social networks. The proposed scheme measures reliability scores through social activities and simplifies a social network by collecting only reliable users. It also derives user influence by considering direct and indirect influences that depends on network degree between users. As a result, the proposed scheme improves the expandability of the user influence. In order to show the superiority of the proposed scheme, we compare it with the existing scheme through performance evaluations in terms of reliability and user influence.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.6
• /
• pp.374-382
• /
• 2020

The purpose of this study is to improve the learning speed of an ammunition stockpile reliability classification artificial neural network model by proposing a normalization method that reduces the number of input variables based on the characteristic of Ammunition Stockpile Reliability Program (ASRP) data without loss of classification performance. Ammunition's performance requirements are specified in the Korea Defense Specification (KDS) and Ammunition Stockpile reliability Test Procedure (ASTP). Based on the characteristic of the ASRP data, input variables can be normalized to estimate the lot percent nonconforming or failure rate. To maintain the unitary hypercube condition of the input variables, min-max normalization method is also used. Area Under the ROC Curve (AUC) of general min-max normalization and proposed 2-step normalization is over 0.95 and speed-up for marching learning based on ASRP field data is improved 1.74 ~ 1.99 times depending on the numbers of training data and of hidden layer's node.

• Korean System Dynamics Review
• /
• v.12 no.1
• /
• pp.89-114
• /
• 2011

With steady increase in the demand for door-to-door delivery services, courier service providers are facing a constant pressure to reduce delivery price in order to secure quantity order and to improve the efficiency and reliability for customer service. The objective of this research is to explain the structure of the door-to-door delivery including door-to-door delivery service demand, sorting capacity in the hub-terminal, and the system performance measures such as service reliability networks using causal loop diagram(CLD). Based on causal relation, this research describes a comprehensive approach to examine how capacity reliability contributes to the renewal of the firm's competences through its reciprocal relationship with travel time reliability and connectivity reliability. Also, this research suggests the policy alternatives to improve effectiveness and efficiency of door-to-door delivery network in response to increase customer satisfaction and profit maximization of the courier service providers: operational, tactical, and strategic levels.

• Journal of the Korean Institute of Telematics and Electronics B
• /
• v.32B no.3
• /
• pp.1-10
• /
• 1995

In this paper, a fault-tolerant Mini-MAP system with high reliability is proposed. For fault-tolerance, the LLC sublayer, MAC sublayer, and physical layer of the Mini-MAP system are dualized. The detection of faults, the replacement of the failed network, and the management of the network are three major functions required for the dualization, and they are performed by ESM(Error Supervisory Machine), EMM(Error Management Machine), and NMM(Network Management Machine) of the proposed fault-tolerant Mini-MAP system, respectively. The ring maintenance function of the MAC sublayer is used for the detection of the faults. In the proposed fault-tolerant Mini-MAP system, the data are received from both of the dualized networks and transmitted to the selected one of the two. We analyze the reliability and the MTTF(Mean Time To Failure) of the proposed fault-tolerant Mini-MAP system and show that it has better performance compared to a general Mini-MAP system.

• Journal of Electrical Engineering and Technology
• /
• v.12 no.5
• /
• pp.1764-1776
• /
• 2017

To achieve economic stability, distribution Company as an economic institution should be managed by various processes. In this way, knowledge of different processes is the first step. Furthermore, expectations, outputs, requirement data, and sub-processes should be extracted and determined. Accordingly, to assign the performance responsibility of each process, the decision-making points must be introduced and, the deviation or change in set-points should be investigated into processes. Also, the performance of processes could be monitored by introducing of the sub-indictors. In this study, a practical method is presented for monitoring of reliability and power loss indices from viewpoint components' supply chain into the distribution network. At first, the visibility model of the supply chain is illustrated by focus group and the sub-indicators are extracted for each process of this chain. Then, validation and verification of the sub-indicators are accomplished by the Delphi method and, an information dashboard is presented by confirmed the sub-indicators and statistics methods. Finally, the proposed method is investigated by real data in a typical network and the results are analyzed.

• The KIPS Transactions:PartD
• /
• v.14D no.6
• /
• pp.649-656
• /
• 2007

Today, controller area network(CAN) is a field bus that is nowadays widespread in distributed embedded systems due to its electrical robustness, low price, and deterministic access delay. However, its use safety-critical applications has been controversial due to dependability limitation, such as those arising from its bus topology. Thus it is important to analyze the performance of the network in terms of load of data bus, maximum time delay, communication contention, and others during the design phase of the controller area network. In this paper, a simulation algorithm is introduced to evaluate the communication performance of the vehicle network and apply software base fault injection techniques. This can not only reduce any erratic implementation of the vehicle network but it also improves the reliability of the system.

• Journal of Information Technology Services
• /
• v.10 no.2
• /
• pp.271-279
• /
• 2011

This paper draws performance results through comparing WMNs' methods when the WMNs are used in tunnel construction sites. There are many advantages of WMNs : lower cost, easy to network maintenance, robustness and reliability within RF-ranges. As a result, using the WMNs would be suitable to employ as a network infrastructure for the construction sites. This paper evaluates the performance of WMNs which we have installed in a tunnel construction. Through the performance results, we conclude the performance of data throughputs gets lower when we perform the network in tunnel environments. We make attempts WMNs' two major methods which are SISC(Single Interface with Single Channel) and MIMC(Multi Interface with Multi Channel) to figure out which method will be better for the construction sites. Through the experiments, the WMN based on the MIMC method was comparatively suitable in network performance aspect for the tunnel Sites.

• International Journal of Reliability and Applications
• /
• v.16 no.1
• /
• pp.35-53
• /
• 2015

This investigation deals with reliability and sensitivity analysis of a repairable embedded system with standby wherein repairman takes multiple vacations. The hardware system consists of 'M' operating and 'S' standby components. The repairman can leave for multiple vacations of random length during its idle time. Whenever any operating unit fails, it is immediately replaced by a standby unit if available. Moreover, governing equations of an embedded system are constructed using appropriate birth-death rates. The vacation and repair time of repairman are exponentially distributed. The matrix method is used to find the steady-state probabilities of the number of failed components in the embedded system as well as other performance measures. Reliability indexes are presented. Further, numerical experiments are carried out for various system characteristics to examine the effects of different parameter. Using a special class of neuro-fuzzy systems i.e. Adaptive Network-based Fuzzy Interference Systems (ANFIS), we also approximate various performance measures. Finally, the conclusions and future research directions are provided.

• Proceedings of the KSR Conference
• /
• 2011.05a
• /
• pp.1695-1700
• /
• 2011

In this paper, we introduce the network infrastructure in an advanced emu test line in Deabul. New technology has been applied to advanced EMU(DMU, integrated broadcasting system, black box and etc). In order to efficient and safely test of new developed train, failure, operation, status of test line and weather information should be monitored in real time. We has implemented a wireless and optical network infrastructure for reliability and scalability. The wireless communication capability between a car and ground is 20Mbps and back-hole network has 50Mbps of the communication performance. The network between test tracks and control office was established in the optical network. That can improve communication reliability.