• Journal of Power Electronics
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• v.19 no.5
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• pp.1270-1277
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• 2019

A problem with virtual synchronous generator (VSG) systems is that they are difficult to operate stably with photovoltaic (PV) power as the DC side. With this problem in mind, a PV-VSG control strategy considering the dynamic characteristics of the DC side is proposed after an in-depth analysis of the dynamic characteristics of photovoltaic power with a parallel energy-storage capacitor. The proposed PV-VSG automatically introduces DC side voltage control for the VSG when the PV enters into an unstable working interval, which avoids the phenomenon where an inverter fails to work due to a DC voltage sag. The stability of the original VSG and the proposed PV-VSG were compared by a root locus analysis. It is found that the stability of the PV-VSG is more sensitive to the inertia coefficient J than the VSG, and that a serious power oscillation may occur. According to this, a new rotor model is designed to make the inertial coefficient automatically change to adapt to the operating state. Experimental results show that the PV-VSG control strategy can achieve stable operation and maximum power output when the PV output power is insufficient.

• Journal of the Korean Institute of Rural Architecture
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• v.1 no.2
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• pp.29-37
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• 1999

This study was analyzed and researched into each gradual properties of housing owner's decision making, for preservation of traditional scenery and search for the way its succession, on the basis of search of the rural area housing owner and the virtual research data. As a result of this study, public company should care and advertise significance of traditional scenery succession to housing owners and architectural planning offices, because the model what public company has been developed and distributed should not be ignored influence on the process of housing owner's decision making.

• IE interfaces
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• v.18 no.1
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• pp.94-103
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• 2005

Digital Manufacturing is a technology to facilitate effective product developments and agile productions by digital environments representing the physical and logical schema and the behavior of real manufacturing system including manufacturing resources, processes and products. A digital factory as a well-designed and integrated environment is essential for successful applications of this technology. In this research, we constructed a sophisticated digital factory of an automotive company’ general assembly shop by measuring and 3-D CAD modeling using parametric methods. Specific parameters of each objects were decided by object-oriented schema of the general assembly shop. It is expected that this method is very useful for constructions of a digital factory, and helps to manage diverse information and re-use 3D models.

• Asia pacific journal of information systems
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• v.26 no.1
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• pp.124-142
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• 2016

Companies operating in social network platforms continue to improve and expand their marketing techniques. This study examines the practice of "gating", which involves virtual barriers between social network users and company content. Gates demand mandatory user endorsements, in the form of a Facebook "Likes", Twitter "retweets" etc., to gain access to company content, such as coupons and rewards,. Gating practices demand a mandatory endorsement before any content consumption takes place. Thus, while user endorsements are assumed to arise voluntarily from trusted known sources, gating practices would appear to violate this assumption. However, whether this violation lessens the effectiveness of gating practices still requires empirical validation. We investigate this question through the use of a unique panel data set that includes data on "like" endorsements obtained from a number of real-world Facebook business pages. Results of the study show that gating practices are effective for endorsement solicitation; however, gates may interfere with more traditional marketing activities.

• IE interfaces
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• v.13 no.2
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• pp.281-287
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• 2000

We studied a model house system on cyberspace using JAVA and VRML in this paper. In the system, users can not only browse the model house using a web browser but also choose options that they want to install in the final house and the chosen options are combined with the figure of the model house on the terminal window in real time. In addition, the information of the chosen options are transferred to a database on a server machine at the construction company and the company can use the information for the customer management. The developed system can be used by a simple EC system since it includes duplex information paths.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2009.05b
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• pp.149-153
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• 2009

Today, the form of competition among companies quickly changes in new paradigm. In the past company activity was performed independently, but now dependently. With global age, that change is essential, the introduction of a system that integrates a series of courses is needed for the success of members. Nevertheless, those change are very slow in construction industry, that causes a lot of loss in project process. Construction industry produce structures with collaboration of other industries. There are difficulties that only one company make it, alone. In this trend, cooperation is essential. but the process of original brings a lot of loss From this perspective, this study will prove dependencies of construction industry. Draw out each factor from industrial cooperation, those analyze correlation with system dynamics. In conclusion, this study performs a basic research about 'Integrated Management System' of construction project.

• Journal of Drive and Control
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• v.20 no.1
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• pp.27-33
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• 2023

From the perspective of dental chair manufacturers, it is important to of localizing hydraulic system in order to secure market competitiveness. This study aims to develop the analysis model of a dental chair which overseas companies secure core technologies. The study follows the steps below. First, the component parts of the solenoid valve unit of a foreign leading company are analyzed and implemented in virtual environment. Second, dynamic behavior scenario is established based on solenoid valve signal chart provided by a foreign leading company. The analysis model is verified and its performance is analyzed using dynamic behavior according to each scenario. Third, a simulation is carried out to determine whether the cylinder velocity of designed hydraulic system surpasses 1cm/s as required by the design.

• Asia pacific journal of information systems
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• v.22 no.2
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• pp.39-69
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• 2012

With the advent of communication technologies including electronic collaborative tools and conferencing systems provided over the Internet, virtual collaboration is becoming increasingly common in organizations. Virtual collaboration refers to an environment in which the people working together are interdependent in their tasks, share responsibility for outcomes, are geographically dispersed, and rely on mediated rather than face-to face, communication to produce an outcome. Research suggests that new sets of individual skill, knowledge, and ability (SKAs) are required to perform effectively in today's virtualized workplace, which is labeled as individual virtual competence. It is also argued that use of online social networking sites may influence not only individuals' daily lives but also their capability to manage their work-related relationships in organizations, which in turn leads to better performance. The existing research regarding (1) the relationship between virtual competence and task performance and (2) the relationship between online networking and task performance has been conducted based on different theoretical perspectives so that little is known about how online social networking and virtual competence interplay to predict individuals' task performance. To fill this gap, this study raises the following research questions: (1) What is the individual virtual competence required for better adjustment to the virtual collaboration environment? (2) How does online networking via diverse social network service sites influence individuals' task performance in organizations? (3) How do the joint effects of individual virtual competence and online networking influence task performance? To address these research questions, we first draw on the prior literature and derive four dimensions of individual virtual competence that are related with an individual's self-concept, knowledge and ability. Computer self-efficacy is defined as the extent to which an individual beliefs in his or her ability to use computer technology broadly. Remotework self-efficacy is defined as the extent to which an individual beliefs in his or her ability to work and perform joint tasks with others in virtual settings. Virtual media skill is defined as the degree of confidence of individuals to function in their work role without face-to-face interactions. Virtual social skill is an individual's skill level in using technologies to communicate in virtual settings to their full potential. It should be noted that the concept of virtual social skill is different from the self-efficacy and captures an individual's cognition-based ability to build social relationships with others in virtual settings. Next, we discuss how online networking influences both individual virtual competence and task performance based on the social network theory and the social learning theory. We argue that online networking may enhance individuals' capability in expanding their social networks with low costs. We also argue that online networking may enable individuals to learn the necessary skills regarding how they use technological functions, communicate with others, and share information and make social relations using the technical functions provided by electronic media, consequently increasing individual virtual competence. To examine the relationships among online networking, virtual competence, and task performance, we developed research models (the mediation, interaction, and additive models, respectively) by integrating the social network theory and the social learning theory. Using data from 112 employees of a virtualized company, we tested the proposed research models. The results of analysis partly support the mediation model in that online social networking positively influences individuals' computer self-efficacy, virtual social skill, and virtual media skill, which are key predictors of individuals' task performance. Furthermore, the results of the analysis partly support the interaction model in that the level of remotework self-efficacy moderates the relationship between online social networking and task performance. The results paint a picture of people adjusting to virtual collaboration that constrains and enables their task performance. This study contributes to research and practice. First, we suggest a shift of research focus to the individual level when examining virtual phenomena and theorize that online social networking can enhance individual virtual competence in some aspects. Second, we replicate and advance the prior competence literature by linking each component of virtual competence and objective task performance. The results of this study provide useful insights into how human resource responsibilities assess employees' weakness and strength when they organize virtualized groups or projects. Furthermore, it provides managers with insights into the kinds of development or training programs that they can engage in with their employees to advance their ability to undertake virtual work.

• Journal of Digital Convergence
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• v.11 no.3
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• pp.209-219
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• 2013

Smart phone environment have an effect on consumer life style, as well as advances in technology. In this paradigm shift on digital convergence make change to commodities, services, and distribution channels for consumers. HomePlus wholesale that is representative distribution company in Korea launched the new distribution channel model that combined off-line store with online store and mobile shopping system called 'smart mobile virtual store'. That is highly praised by abroad media and festivals. This study is an exploratory study on consumer-centric smart mobile virtual store of HomePlus. There are value and chance for developing the new digital distribution model, in this study, because the case study and evaluation of consumers is important in this momentous time.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.6
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• pp.967-975
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• 2010

There have been a lot of efforts on the improvement for the ride comfort and handling stability of the combat vehicles. Especially most of vehicles for military purpose have bad inertial condition and severe operating condition such as the rough road driving, and need a high mobility in the emergency status. It is necessary to apply the controlled suspension system in order to improve the vehicle mobile stability and ride comfort ability of crews. A feasibility study is performed on the application of the semi-active suspension system with a magneto-rheological controlled shock absorber for a $6{\times}6$ combat vehicle. First, the dynamic simulation model of the vehicle including the control model for the semi-active suspension system was executed. Based on this model, a hardware-in-the-loop simulation(HILS) system which has a semi-active suspension controller hardware was constructed. After full vehicle simulations were performed in virtual proving courses with this system, the semi-active suspension system was proven to give better ride comfort and handling stability in comparison with the conventional passive suspension system.