• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.8
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• pp.3568-3584
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• 2016

In mobile opportunistic networks (MONs), human-carried mobile devices such as PDAs and smartphones, with the capability of short range wireless communications, could form various intermittent contacts due to the mobility of humans, and then could use the contact opportunity to communicate with each other. The dynamic changes of the network topology are closely related to the human mobility patterns. In this paper, we propose a social motivation-aware mobility model for MONs, which explains the basic laws of human mobility from the psychological point of view. We analyze and model social motivations of human mobility mainly in terms of expectancy value theory and affiliation motivation. Furthermore, we introduce a new concept of geographic functional cells, which not only incorporates the influence of geographical constraints on human mobility but also simplifies the complicated configuration of simulation areas. Lastly, we validate our model by simulating three real scenarios and comparing it with reality traces and other synthetic traces. The simulation results show that our model has a better match in the performance evaluation when applying social-based forwarding protocols like BUBBULE.

• Journal of Information Technology Services
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• v.20 no.2
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• pp.147-166
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• 2021

As vehicle sharing service is being widely used in China. The sharing economy appeared to be a way to make people's lives more convenient and to utilize limited resources efficiently. Sharing economy companies have created an app to satisfy users' needs with providing more benefits. Although research on vehicle sharing services has been continuously conducted at the level of the sharing economy, there are not many empirical studies related to the perception of the sharing economy from the consumer's point of view. In this sense, this study considered the perceived relationship benefits (social benefits, economic benefits, psychological benefits, and functional benefits) of Didi chuxing service as the key independent variables influencing users' confirmation and satisfaction, And suggests that users' confirmation and satisfaction are the key determinants of Didi continuance intention . To test the proposed research model, this study conducted structural equation model using 268 data collected on the users who have experience of Didi service. According to the empirical analysis results, This study verifies that: First, social benefits, economic benefits, psychological benefits, and functional benefits are determinants of user's satisfaction. Second, expectation confirmation depends on economic benefits, psychological benefits, functional benefits and social influence, meanwhile, social benefit has no effect on expectation confirmation. Third, expectation confirmation is proved to be a positive predictor of users' satisfaction. Finally, this results indicate that continuous use intention is determined by users' satisfaction.

• Korean Journal of Organic Agriculture
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• v.22 no.2
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• pp.335-345
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• 2014

The productivity decrease in environment-friendly farming is the biggest obstacle for the development of environment-friendly food market. This paper aimed to analyze the productivity change in environment-friendly farming of fruit vegetables (oriental melon, watermelon, and strawberry). Box-Cox transformation model was used to infer the functional form of productivity change. The results showed that the periods of productivity restoration to 90% level in oriental melon, strawberry, and watermelon were 14.1 years, 11.4 years, and 6.0 years, respectively. The forms of productivity restoration of fruit vegetables showed differences due to their growth characteristics, incidences of crop pests, preference for the environment- friendly agricultural products, cultivation period and so on. Because the form and period of productivity restoration were different depending on kinds of fruit vegetable, the government policy should be established considering this point of view.

• Journal of the Korea Safety Management & Science
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• v.12 no.3
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• pp.327-332
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• 2010

It is necessary that End-of-life Vehicle (ELV) should be recycled from the point of view of environmental preservation and resource recycling. This paper deals with two issues. The first one is the basic functional construction and plant layout of the ELV dismantling system that can maximize the reusability of parts and the recyclability of materials. The second issue is the development of a simulation model which can be used to estimate the performance of the layout design. The simulator has been interfaced with an interactive layout design system, and used to effectively determine an optimal layout design of the ELV dismantling system.

• Journal of Power Electronics
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• v.19 no.2
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• pp.519-528
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• 2019

The unified power quality conditioner (UPQC) is an effective custom power device that is used at the point of common coupling to protect loads from voltage and current-related PQ issues. Currently, most researchers have studied series unit and parallel unit models and an idealized transformer model. However, the interactions of the series and parallel converters in AC-link are difficult to analyze. This study utilizes an equivalent transformer model to accomplish an electric connection of series and parallel converters in the AC-link and to establishes a precise unified mathematical model of the UPQC. The strong coupling interactions of series and parallel units are analyzed, and they show a remarkable dependence on the excitation impedance of transformers. Afterward, a feed-forward decoupling method based on a unified model that contains the uncertainty components of the load impedance is applied. Thus, this study presents an adaptive method to estimate load impedance. Furthermore, simulation and experimental results verify the accuracy of the proposed modeling and decoupling algorithm.

• Journal of the Korea Safety Management & Science
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• v.23 no.2
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• pp.65-77
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• 2021

This paper conducted an empirical study to identify the causal relationship of factors affecting the purchase intention of automobiles from the customer's point of view. This study sets the purchase intention as a result variable and constructs a causal model with brand image, product attributes (exdogenous variable), and customer value (endogenous variable) as a cause that affects purchase intention. The results of this study are summarized as follows. First, the symbolic image of the brand was found to have a very significant effect on customer value (p=0.01), and the external attribute of the product also had a significant effect on customer value (p=0.1). Second, customer value was found to have a very significant effect on purchase intention (p=0.01), and the functional image of the brand also had a significant effect on purchase intention (p=0.1). Third, there is a strong positive (+) correlation between the functional image of the brand and the symbolic image of the brand, the intrinsic attribute of the product, and the external attribute of the product, and also between the symbolic image of the brand and the intrinsic attribute of the product and There was also a positive (+) correlation between extrinsic attributes. Therefore, in order to increase customer value, automobile manufacturing companies have a functional value of products from a customer-oriented perspective. It is judged that every effort should be made to maintain a lasting relationship by grasping the values of customers, which are social values, emotional values, situational values, and cognitive values.

• Archives of Plastic Surgery
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• v.37 no.4
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• pp.329-334
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• 2010

Purpose: Adhesion after flexor tendon injury is a result of fibrosis between tendon and tendon sheath. This, finally interfere with gliding mechanism of tendon and results in functional problem of hands. Therefore, there have been many trials to reduce adhesion around the tendon. However, there is no standard procedure clinically practiced in hospitals. Mitomycin-C is an antineoplastic alkylating agent that decrease fibroblast proliferation and scar formation. It is commonly used in many surgery to reduce postoperative adhesion. This study was designed to observe the effect of Mitomycin-C on preventing adhesion in injured flexor tendon. Methods: The deep flexor tendon of digit 2 and 4 in the left forepaw of 15 New Zealand White rabbits were subjected to partial tenotomy. In study group, injury site was exposed to a single 5-minute application of Mitomycin-C, and in control group was left untreated. Digit 2 and 4 in the right forepaw of each rabbit were considered as nonadhesion control group. After 2 weeks, the animals were sacrificed and digits were amputated for biomechanical test and histological study. Results: In biomechanical study to measure yield point, mean yield point of non-adhesion control was $17.43{\pm}2.33$ and $25.07{\pm}4.03$ for adhesion control, which proves increase of adhesion in adhesion control group (p<0.05) in 95% confidence. In Mitomycin-C group, mean yield point was $12.71{\pm}4.97$. Compared with adhesion control, there was decrease in adhesiveness in Mitomycin-C group (p<0.05) in 95% confidence. In histological study, the result of adhesion control revealed massive adhesions of bony structure, fibrotic tissue and tendon structure with ablation of the border. However in Mitomycin-C group, we could find increased fibrotic tissue, but adhesion is much lesser than adhesion group and borders between structures remain intact. Conclusion: This study suggests that Mitomycin-C can significantly reduce adhesion of injured flexor tendon in rabbit model.

• Convergence Security Journal
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• v.14 no.7
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• pp.45-51
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• 2014

The most important point in the QoS management system to ensure the quality of the IoT system design goal is quality measurement system and the quality evaluation system. This research study is a matrix model for the IoT based on key quality measures by diagnosis system structure and function. Developing for the quality metrics measured Internet of Things environment will provide the foundation for the Internet of Things quality measurement/analysis. IoT matrix system for quality evaluation is a method to describe the functional requirements and the quality requirements in a single unified table for quality estimation performed. Comprehensive functional requirements and quality requirements by assessing the association can improve the reliability and usability evaluation. When applying the proposed method IoT quality can be improved while reducing the QoS signaling, the processing, the basis for more efficient quality assurances as a whole.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.9 no.1
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• pp.59-65
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• 1998

Instead of brilliant advancement of the organ transplantation in the medical fields, laryngeal transplantation still has couple of problems to be solved before trial on human. Among them functional restoration of the implanted larynx is the most important point. Recent advancement in animal model studies showed possibility of solving the main problem. Eighteen cases of canine laryngeal transplantation in mongrel dogs were done in this department. One cranial artery and two external jugular veins were connected. External and internal branches of the superior layngeal nerve and anterior and posterior branches of the recurrent laryngeal nerve were connected individually. Only two dogs have lived longer than 4 weeks(4weeks, and 10 1/2weeks) and they died unfortunately due to asphixia caused by obstruction of the cannula. Thirteen dogs only lived five days through 15 days. The main causes of the failure were obstruction of the connecting vein, pharyngocutaneous fistula and the wound infection. Although the result was not good enough to evaluate the functional restoration of the implanted larynx, the implanted larynges from the two dogs lived longer than minimum criteria of long term survival(4 weeks) were relatively good in shape at the time of autopsy. This program will be continued after renovation of the animal lab. facilities.

• Journal of the Korean Society of Physical Medicine
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• v.5 no.2
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• pp.265-272
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• 2010

Purpose : This study was investigated the effect of electroacupuncture stimulation on the change of blood biochemical components in the rat spinal cord injury(SCI) damaged by the 6-hydroxydopamine. Methods : SCI model rats were damaged in L1-L2 injected with 6-hydroxydopamine. The thirty Sprague-Dawley adult male rats were randomly divided into normal group, control group and electroacupuncture group. Experimental groups were applied as electroacupuncture(Es-160, ITO, Japan) for 15minutes during the low frequency(2 Hz) stimulation to zusanli. The enzyme concentration levels analysis of the hematological changes were measured of Glutamate Oxaloacetate Transaminase(GOT), Glutamate Pyruvate Transaminase(GPT), Lactate dehydrogenase(LDH) and motor function recovery change was evaluated by the rota-rod test. Results : This study were as follow : The concentration of GOT, LDH in experimental group was lower than control group(p<.05). The experimental group showed increase of motor function recovery more in compared to control group(p<.05). Conclusion : The results of this study showed that electroacupuncture to zusanli point have an effect on functional recovery after the 6-hydroxydopamine induced SCI in rats.