• Title/Summary/Keyword: 시스템신뢰성

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A Study on the Current Situation and Problems of Agricultural Products e-Commerce in Korea (B2B 농산물 전자상거래 활성화 방안과 과제에 관한 연구)

  • Kim, Kyu-Hyong;Lee, Moon-Seok
    • International Commerce and Information Review
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    • v.13 no.1
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    • pp.29-52
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    • 2011
  • A predictable and manageable output is desirable for most businesses. However, it is very difficult to control the quality and quantity of products in the food and agriculture business. Predictable outputs help managers plan their marketing, sales, and inbound and outbound logistics, but these are not easy to achieve in the food and agriculture business. Various industries have adopted different levels of automation and utilization of information systems for quality/quantity control; however e-Commerce of the food and agriculture industry is far behind those of other industries. Today, the food and agriculture industry is supposed to be more integrated than ever in order to reduce risks and improve processing costs, from farm to table. Since its operations including production, processing, storage, distribution, and management are dispersed all over the world, the food and agricultural industries now depend more on IT than other industries. This study attempts to develop a framework to analyze the current situation of agricultural product e-Commerce in Korea, and finds out the actual situation of the farmers operating on-line shopping systems through the developed framework and suggests some improvements.

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LLR-based Cooperative ARQ Protocol in Rayleigh Fading Channel (레일리 페이딩 채널에서 LLR 기반의 협력 ARQ 프로토콜)

  • Choi, Dae-Kyu;Kong, Hyung-Yun
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.45 no.4
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    • pp.31-37
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    • 2008
  • Conventional cooperative communications can attain gain of spatial diversity and path loss reduction because destination node independently received same signal from source node and relay node located between source node and destination node. However, these techniques bring about decreased spectral efficiency with relay node and increased complexity of receiver by using maximal ratio combining (MRC). This paper has proposed cooperative ARQ protocol that can improve the above problems and can get the better performance. This method can increase the spectral efficiency than conventional cooperative communication because if the received signal from source node is satisfied by the destination preferentially, the destination transmits ACK message to both relay node and source node and then recovers the received signal. In addition, if ARQ message indicates NACK relay node operates selective retransmission and we can increase reliability of system compared with that of general ARQ protocol in which source node retransmits data. In the proposed protocol, the selective retransmission and ARQ message are to be determined by comparing log-likelihood ratio (LLR) computation of received signal from source node with predetermined threshold values. Therefore, this protocol don't waste redundant bandwidth with CRC code and can reduce complexity of receiver without MRC. We verified spectral efficiency and BER performance for the proposed protocol through Monte-Carlo simulation over Rayleigh fading plus AWGN.

The Effects of Transformational Leadership on Job Satisfaction and Job Performance: Focused on Deluxe Hotel Culinary Staff (변혁적 리더십이 직무만족 및 직무성과에 미치는 영향 - 특급호텔 조리사를 중심으로 -)

  • Ryu, Ji-Yong;Park, Ji-Soo;Park, Ki-Bong
    • Culinary science and hospitality research
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    • v.19 no.3
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    • pp.194-208
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    • 2013
  • This study presented a theoretical research system about the impact of boss' transformational leadership that is recognized by super luxury hotel chefs on their job satisfaction and performance, and on the basis of this theoretical background, the model was derived and the hypothesis was confirmed by empirical research. A frequency analysis was conducted to determine the general characteristics of the 245 samples collected in this study, an exploratory factor analysis for the verification of the validity of boss' transformational leadership, employees' job satisfaction and job performance, and 'Cronbach's a' was used for the verification of reliability. In addition, a canonical correlation analysis was used to determine the relationship between transformational leadership, job satisfaction and job performance, and the influencing relations of variables were verified by running a multiple regression analysis through SPSS ver 18.0 statistical package in order to verify this research model and hypothesis. The results of this study can be summarized as follows: First, it was shown that the transformational leadership charisma (p<0.01) and only the individual concern (p<0.1) had a positive influence on job satisfaction. Second, as a result of understanding the impact of the transformational leadership on the job performance through a regression coefficient, it was shown that only boss' intellectual stimulation had an impact on the chef's job performance (p<0.005). Through the results of an empirical analysis that boss' transformational leadership had a correlation and a significant impact on job satisfaction and job performance, the effort of providing the systematic support and motivational aspects of supporting environment will be needed.

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A Study on the Effects of Internal Marketing on Service Quality and Customer Satisfaction in Shipping Companies (해운기업의 내부마케팅이 서비스품질과 고객만족에 미치는 영향)

  • Lee, Sang-Pyeong;Shin, Han-Won;Park, Sung-Keon
    • Journal of Korea Port Economic Association
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    • v.26 no.4
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    • pp.122-146
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    • 2010
  • This purpose of this study is to analyze the causal relation among constituent concepts and verify the relation among internal marketing, service quality and customer satisfaction in shipping companies. To achieve the goal of this study, the author studied literatures on internal marketing, service quality and customer satisfaction, and carried out a survey targeting people working for shipping companies and international logistics freight forwarders to make an empirical analysis. The results are as follows. It was confirmed that education and training, reward system, empowerment among internal marketing elements of a shipping company have a positive effect on the service quality and customer satisfaction of the shipping company, and the service quality of a shipping company also has a positive effect on customer satisfaction. As it can be known from these results, it would be necessary to concentrate on internal marketing of a shipping company in order to increase service quality and customer satisfaction.

The study on scheme for train position detection based on GPS/DR (GPS/DR기반의 차상열차위치검지방안 연구)

  • Shin, Kyung-Ho;Joung, Eui-Jin;Lee, Jun-Ho
    • Proceedings of the KSR Conference
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    • 2006.11b
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    • pp.802-810
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    • 2006
  • For a thorough train control, the precise train position detection is necessarily required. The widely used current way for train position detection is the one of using track circuits. The track circuit has a simple structure, and has a high level of reliability. However trains can be detected only on track circuits, which have to be installed on all ground sections, and much amount of cost for its installation and maintenance is needed. In addition, for the track circuit, only discontinuous position detection is possible because of the features of the closed circuit loop configuration. As the recent advances in telecommunication technologies and high-tech vehicle-based control equipments, for the train position detection, the method to detect positions directly from on trains is being studied. Vehicle-based position detection method is to estimate train positions, speed, timing data continuously, and to use them as the control information. In this paper, the features of GPS navigation and DR navigation are analyzed, and the navigation filters are designed by constructing vehicle-based train position detection method by combining GPS navigation and DR navigation for their complementary cooperation, and by using kalman filter. The position estimation performance of the proposed method is also confirmed by simulations.

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Modeling of the Charge-discharge Behavior of a 12-V Automotive Lead-acid Battery (차량용 12-V 납축전지의 충·방전 모델링)

  • Kim, Ui Seong;Jeon, Sehoon;Jeon, Wonjin;Shin, Chee Burm;Chung, Seung Myun;Kim, Sung Tae
    • Korean Chemical Engineering Research
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    • v.45 no.3
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    • pp.242-248
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    • 2007
  • For an optimal design of automotive electric system, it is important to have a reliable modeling tool to predict the charge-discharge behaviors of the automotive battery. In this work, a two-dimensional modeling was carried out to predict the charge-discharge behaviors of a 12-V automotive lead-acid battery. The model accounted for electrochemical kinetics and ionic mass transfer in a battery cell. In order to validate the modeling, modeling results were compared with the experimental data of the charge-discharge behaviors of a lead-acid battery. The discharge behaviors were measured with three different discharge rates of C/5, C/10, and C/20 at operating temperature of $25^{\circ}C$. The batteries were charged with constant current of 30A until the charging voltage reached to a predetermined value of 14.24 V and then the charging voltage was kept constant. The discharge and charge curves from the measurements and modeling were in good agreement. Based on the modeling, the distributions of the electrical potentials of the solid and solution phases, the porosity of the electrodes, and the current density within the electrodes as well as the acid concentration can be predicted as a function of charge and discharge time.

Highly Reliable Fault Detection and Classification Algorithm for Induction Motors (유도전동기를 위한 고 신뢰성 고장 검출 및 분류 알고리즘 연구)

  • Hwang, Chul-Hee;Kang, Myeong-Su;Jung, Yong-Bum;Kim, Jong-Myon
    • The KIPS Transactions:PartB
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    • v.18B no.3
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    • pp.147-156
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    • 2011
  • This paper proposes a 3-stage (preprocessing, feature extraction, and classification) fault detection and classification algorithm for induction motors. In the first stage, a low-pass filter is used to remove noise components in the fault signal. In the second stage, a discrete cosine transform (DCT) and a statistical method are used to extract features of the fault signal. Finally, a back propagation neural network (BPNN) method is applied to classify the fault signal. To evaluate the performance of the proposed algorithm, we used one second long normal/abnormal vibration signals of an induction motor sampled at 8kHz. Experimental results showed that the proposed algorithm achieves about 100% accuracy in fault classification, and it provides 50% improved accuracy when compared to the existing fault detection algorithm using a cross-covariance method. In a real-world data acquisition environment, unnecessary noise components are usually included to the real signal. Thus, we conducted an additional simulation to evaluate how well the proposed algorithm classifies the fault signals in a circumstance where a white Gaussian noise is inserted into the fault signals. The simulation results showed that the proposed algorithm achieves over 98% accuracy in fault classification. Moreover, we developed a testbed system including a TI's DSP (digital signal processor) to implement and verify the functionality of the proposed algorithm.

Discovering Association Rules using Item Clustering on Frequent Pattern Network (빈발 패턴 네트워크에서 아이템 클러스터링을 통한 연관규칙 발견)

  • Oh, Kyeong-Jin;Jung, Jin-Guk;Ha, In-Ay;Jo, Geun-Sik
    • Journal of Intelligence and Information Systems
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    • v.14 no.1
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    • pp.1-17
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    • 2008
  • Data mining is defined as the process of discovering meaningful and useful pattern in large volumes of data. In particular, finding associations rules between items in a database of customer transactions has become an important thing. Some data structures and algorithms had been proposed for storing meaningful information compressed from an original database to find frequent itemsets since Apriori algorithm. Though existing method find all association rules, we must have a lot of process to analyze association rules because there are too many rules. In this paper, we propose a new data structure, called a Frequent Pattern Network (FPN), which represents items as vertices and 2-itemsets as edges of the network. In order to utilize FPN, We constitute FPN using item's frequency. And then we use a clustering method to group the vertices on the network into clusters so that the intracluster similarity is maximized and the intercluster similarity is minimized. We generate association rules based on clusters. Our experiments showed accuracy of clustering items on the network using confidence, correlation and edge weight similarity methods. And We generated association rules using clusters and compare traditional and our method. From the results, the confidence similarity had a strong influence than others on the frequent pattern network. And FPN had a flexibility to minimum support value.

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Energy-Efficient Multipath Routing Protocol for Supporting Mobile Events in Wireless Sensor Networks (무선 센서 네트워크에서 이동 이벤트를 지원하기 위한 에너지 효율적인 멀티패스 라우팅 프로토콜)

  • Kim, Hoewon;Lee, Euisin
    • KIPS Transactions on Computer and Communication Systems
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    • v.5 no.12
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    • pp.455-462
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    • 2016
  • Wireless sensor networks have been researched to gather data about events on sensor fields from sources at sinks. Multipath routing is one of attractive approaches to reliably send data against the problem of frequent breakages on paths from sources to sinks due to node and link failures. As mobile events such as humans, animals, and vehicles are considered, sources may be continuously generated according to the movement of the mobile event. Thus, mobile events provide new challenging issue in multipath routing. However, the research on multipath routing mainly focus on both efficient multipath construction from sources to static sinks and fast multipath reconstruction against path breakages. Accordingly, the previous multipath routing protocols request each source continuously generated by a mobile event to construct individual multipath from the source to sinks. This induces the increase of multipath construction cost in the previous protocols in proportion to the number of source. Therefore, we propose efficient multipath routing protocol for supporting continuous sources generated by mobile events. In the proposed protocol, new source efficiently reconstructs its multipath by exploiting the existing multipath of previous sources. To do this, the proposed protocol selects one among three reconstruction methods: a local reconstruction, a global partial one, and a global full one. For a selection decision, we provide an analytical energy consumption cost model that calculates the summation of both the multipath reconstruction cost and the data forwarding cost. Simulation results show that the proposed protocol has better performance than the previous protocol to provide multipath routing for mobile events.

A Public Opinion Survey on the Crime Prevention of the Private Security (민간경비의 범죄예방 역할에 대한 시민의식조사)

  • Gong, Bae-Wan
    • Korean Security Journal
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    • no.16
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    • pp.1-17
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    • 2008
  • This study is trying to analyse the private security prevention role of citizen, For this analyse the public opinion survey on the crime prevention of the private security was carried in Kyungnam area about the crime prevention system and the storage and institution, the role of the crime prevention of private security etc. So that, we have experimented a fact-finding survey about civil consciousness. The result of this fact-finding survey about crime prevention system is on the hand pointed out the circumscription of the police power, and the other hand they have the age-old ceremonies on the dependence about police system. Because the public security order needs the compelling power to maintenance the peace and this power is exercising only by police. They don't have the trust about the role of the private security as the crime prevention institution. But, they consider the private security is just for anyone in particular and special class by their demand. And also, they consider the private security is very expensive to utilize for their security in the everyday life. There for, some people have trust for the private security and if they have a chance for the security, they consider to utilize the private security for their safe life as an security agency. The private security has a powerful experts and so many high-tech equipments for the security. Thus, we have to find a solution to get the best out of it. Because the private security is also a part of crime prevention institution as the police agency.

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