• Proceedings of the Korea Society for Simulation Conference
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• 2001.10a
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• pp.440-443
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• 2001

As inter-network traffics grows rapidly, the router systems as a network component becomes to be capable of not only wire-speed packet processing but also plentiful programmability for quality services. A network processor technology is widely used to achieve such capabilities in the high-end router. Although providing two such capabilities, the network processor can't support a deep packet processing at nominal wire-speed. Considering QoS may result in performance degradation of processing packet. In order to achieve foster processing, one chipset of network processor is occasionally not enough. Using more than one urges to consider a problem that is, for instance, an out-of-order delivery of packets. This problem can be serious in some applications such as voice over IP and video services, which assume that packets arrive in order. It is required to develop an effective packet processing mechanism leer using more than one network processors in parallel in one linecard unit of the router system. Simulation analysis is also needed for verifying the mechanism. We propose the packet processing mechanism consisting of more than two NPs in parallel. In this mechanism, we use a load-balancing algorithm that distributes the packet traffic load evenly and keeps the sequence, and then verify the algorithm with simulation analysis. As a simulation tool, we use DEVSim++, which is a DEVS formalism-based hierarchical discrete-event simulation environment developed by KAIST. In this paper, we are going to show not only applicability of the DEVS formalism to hardware modeling and simulation but also predictability of performance of the load balancer when implemented with FPGA.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.5
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• pp.113-119
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• 2008

Conventional 1-1-1 cooperative protocol offers path-loss gain as advantage of multi-hop and spatial diversity which is equivalent to MIMO system. This protocol is enable to get higher reliability and reduction of power consumption than those of the single-hop or multi-hop. But the 1-1-1 cooperative protocol get only the diversity order 2 and limited path-loss reduction gain because this protocol has a single cooperative relay. We propose 1-2-1 cooperative protocol using two cooperative relays R1, R2. The 1-2-1 cooperative protocol can improve path-loss reduction and increase diversity order 3. Moreover, the cooperative relay R2 attains diversity order 2. The signaling method in transmission uses DF (Decode and Forward) or DR (Decode and Reencode) and 1-2-1 DF/DR cooperative protocol are applied to clustering based wireless sensor networks (WSNs). Simulations are performed to evaluate the performance of the protocols under Rayleigh fading channel plus AWGN (Additive White Gaussian Noise).

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.11
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• pp.1225-1230
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• 2015

MAC protocol for WBAN performs CSMA/CA(:Carrier Sense Multiple Access with Collision Avoidance)algorithm that handles traffic which occurs in emergency with top priority in order to deal with variable data of sensor node for medicine. Emergency message that node sends undergoes collision and delay of transmission by retransmission of emergency message and waste of energy by retransmission. This paper suggests algorithm that minimizes loss of frame caused by collision and applies different backoff parameters by setting order of priority between MAC instruction frame and data frame in CSMA/CA algorithm case which applies order of priority queuing to improve aforementioned problem. According to performance evaluation, it has been found that using suggested MAC protocol showed lower collision probability, higher packet transmission processing ratio and lower packet loss compared with using IEEE 802.15.6.

• Journal of Korea Technology Innovation Society
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• v.21 no.2
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• pp.615-635
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• 2018

The Korean government has selected job creation policy as first goal in order to overcome the recession and response of 4th industrial revolution. Technology based start up is worth noting in order to job creation. Because the ripple effect of technology based start up is higher than self-employment. Therefore, the government and the private sector conduct various policies and services for the vitalization of technology based start up. In order for technology based start up to be successful, it is necessary to maximize personal (founder) capacity. In this study, the correlation between "features of personal (motivation, capability, experience, entrepreneurship)", "competitiveness of company" and "corporate performance" was analyzed using structural equation modeling (SEM). Also, in this study analyzed the differences between 2 groups based on the career of CEO (work for government funded research institutes VS the others). This study can be utilized when policy making and practice about technology based start-up.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.49 no.3
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• pp.145-156
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• 2000

In this paper, we propose a new methodology which includes the optimal design procedure of Polynomial Neural Networks(PNN) structure for model identification of complex and nonlinear system. The proposed PNN algorithm is based on GMDA(Group Method of Data handling) method and its structure is similar to Neural Networks. But the structure of PNN is not fixed like in conventional Neural Networks and can be generated. The each node of PNN structure uses several types of high-order polynomial such as linear, quadratic and cubic, and is connected as various kinds of multi-variable inputs. In other words, the PNN uses high-order polynomial as extended type besides quadratic polynomial used in GMDH, and the number of input of its node in each layer depends on that of variables used in the polynomial. The design procedure to obtain an optimal model structure utilizing PNN algorithm is shown in each stage. The study is illustrated with the aid of pH neutralization process data besides representative time series data for gas furnace process used widely for performance comparison, and shows that the proposed PNN algorithm can produce the model with higher accuracy than previous other works. And performance index related to approximation and prediction capabilities of model is evaluated and also discussed.

• The Journal of Information Systems
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• v.25 no.3
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• pp.175-196
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• 2016

Purpose The development of new products in automobile parts industry plays an important role. Nowadays, automobile industry is one of the most important industries in the world, because automobile industry includes the industries of steel, machinery, electronic, etc. As a result, automobile industry embodies a country's level of development and competitiveness. The purpose of this study is to analyze the relationship between team characteristics such as communication, familiarity, and contiguity, and team performance through TMS in the process of new products development in automobile parts industry. Design/Methodology/Approach Based on real phenomenon of Korean automobile parts industry, this study tried to figure out the influence of TMS between team members for new product development on team performance. Thus, this study adopts communication, familiarity and contiguity as antecedents, and TMS with specialty, credibility and coordination as a mediating variable, and adopts team performance as a dependent variable. The data of questionnaire were collected from team managers who belong to new product development team in automobile parts firms. 171 questionnaires as data unit of group level from 80 Korean automobile parts firms were collected using face-to-face interview methods. Findings This study proved empirically that the relationship between antecedents and TMS has a positive influence, and TMS also has a positive influence on team performance. This study provides the managers an insight that automobile parts companies should pay more attention to set up TMS in order to improve higher performance between their team members for new product development of automobile parts.

• Korea Journal of Hospital Management
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• v.25 no.2
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• pp.57-68
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• 2020

Purpose: The purpose of this study is to determine the influence of hospital employees' perceptions and performance expectations on IT technologies introduction and intention to use in the Fourth Industrial Revolution. Methodology: A survey was conducted on 524 employees at 42 hospitals. Pearson's correlation analysis, regression analysis, Sobel test, and structural equation were used for the analysis. Findings: The factors of technical situation (complexity, compatibility, technical readiness, and security concerns), those of environmental situation (competitive pressure and regulatory support), and organizational situation (top management support and costs) have influenced on the recognition of employees in the hospital and the performance expectations. IT technology introduction and use intention have been influenced by technical situation, organizational situation, and environmental situation in order. But security concerns and cost factors have not statistically affected. In addition, due to the perception and performance expectations of hospital employee who have a role in mediating the introduction and use intention of IT technology, the greater the perception and performance expectations of hospital employees, the higher the intention of introduction and usage of IT technology. Practical Implications: Rather than considering the position of external customers and the position of competitive hospitals, more attention is required for the perception and performance expectations of the internal members.

• Journal of Advanced Marine Engineering and Technology
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• v.41 no.2
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• pp.140-145
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• 2017

Newly designed vapor-injection heat pumps have been proposed and analyzed in the present study. An economizer-type vapor-injection (V-I) system has been employed as the standard system because of its reliability and simple control method. The V-I system has a re-cooler and re-heater for cooling and heating, respectively. Solar panels have been installed in the V-I heat pump as well as in the re-heater in order to enhance heating capacity and performance. R410A has been employed as a working fluid and performance analysis has been conducted under various conditions. Results are summarized as follows: (1) The V-I system with the re-cooler yielded a marginally higher coefficient of performance (COP) than the conventional V-I refrigeration system. (2) By increasing the re-cooler cooling capacity, enhanced system performance as compared to the conventional V-I system was observed. (3) The re-heater negatively affected the system performance; hence, the V-I heat pump with the re-heater yielded a lower COP than that of the conventional V-I heat pump used for heating. (4) Although the solar panels increased the system performance, this increase could not offset performance degradation by the re-heater.

• Journal of Korean society of Dental Hygiene
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• v.15 no.1
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• pp.11-17
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• 2015

Objectives: The purpose of the study is to investigate the relationship between noise awareness, hearing ability, and dental hygiene performance in dental hygienists. Methods: The subjects were 234 dental hygienists in Seoul, Gyeonggi-do, and Incheon. The questionnaire consisted of 3 questions of general characteristics of the subjects, 1 question of noise awareness, 3 questions of hearing ability, 5 questions of dental hygiene performance, 1 question of noise reduction necessity, and 2 questions of noise control. Noise awareness, dental hygiene performance, and noise reduction necessity were measured by Likert 5 scale. Cronbach's alpha was 0.825 in dental hygiene performance reliability. Results: There was a significant difference in noise recognition by age(p<0.01) and working career(p<0.05). Those who pumped up the higher TV volume accounted for 31.6% and 3.0% had hearing impairment in the regular health checkup. 3.4% of the respondents complained of hearing loss, ear fluid, and equilibrium problem diagnosed by the doctors. The relationship between the type of workplace environment and task performance showed a significant difference. Those who work in the dental hospitals had high score of 3.43, while those who work in dental clinics had 3.20(p<0.05). The increased level of noise recognition affected the task performance and it is necessary to reduce the noise level. More try must be focused on the noise exposure prevention. Conclusions: In order to reduce the problems due to noise and improve their quality of life, it is necessary to change the noise recognition in the work place.

• Journal of the Korea Society of Computer and Information
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• v.17 no.2
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• pp.231-239
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• 2012

A company's reliance on plants is growing in the area of production and service. Therefore, the importance of the work on plants in order to manage them efficiently is growing. Effective plant management increases the durability and efficiency of the plant. An organized BSC also increases the workers' will to work harder which is to bring the higher quality of plant management. In this way, however, it has studied with variety ways to assess plant management task for performance evaluation, there is a little deficiency that the study of methodical performance evaluation that based on the some strategies. The BSC, the very way, and it has been utilized in balanced and methodical performance evaluation means in widespread fields with strategy as the center to get visions. In this study, I have developed the performance evaluation system for plant management, appling BSC concept.