• The KIPS Transactions:PartD
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• v.11D no.4
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• pp.783-798
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• 2004

An e-business client application in ubiquitous mobile computing environment may become disconnected from the enterprise server due to broken communication connections caused by the limitation of mobile computing environments(limited battery life of the mobile device, low bandwidth communication, incomplete wireless communication infrastructure, etc). It Is even Possible that mobile client application Intentionally operates in disconnected mode to reduce communication cost and the power consumption of the mobile device. We use “data hoarding” as a means of providing local autonomy to allow transactions to be processed and committed on the mobile host despite of disconnection. The key problem to this approach is the synchronization problem that serialize potentially conflicting updates from disconnected clients on master objects of the server database. In this paper, we present a new transaction synchronizing method that splits a transaction into a set of independent component transactions and give the synchronization priority on each component taking the possibility of use and conflicts in the server into consideration. Synchronization is performed component by component based un synchronization priority. After the Preferred component of a no bile transaction succeeds in synchronization with the server, the mobile transaction can pre-commit at server. A pre-committed transaction's updated value is made visible at server before the final commit of the transaction. The synchronization of the component with low synchronization priority can be delayed in adaption to wireless bandwidth and computing resources. As a result, the availability of important data updated by mobile client is increased and it can maximize the utilization of the limited wireless bandwidth and computing resources.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.7
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• pp.3413-3430
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• 2017

With the fast increasing popularity of mobile services, ubiquitous mobile devices with enhanced sensing capabilities collect and share local information towards a common goal. The recent Mobile Crowd Sensing (MCS) paradigm enables a broad range of mobile applications and undoubtedly revolutionizes many sectors of our life. A critical challenge for the MCS paradigm is to induce mobile devices to be workers providing sensing services. In this study, we examine the problem of sensing task assignment to maximize the overall performance in MCS system while ensuring reciprocal advantages among mobile devices. Based on the overlapping coalition game model, we propose a novel workload determination scheme for each individual device. The proposed scheme can effectively decompose the complex optimization problem and obtains an effective solution using the interactive learning process. Finally, we have conducted extensive simulations, and the results demonstrate that the proposed scheme achieves a fair tradeoff solution between the MCS performance and the profit of individual devices.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.7
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• pp.1404-1409
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• 2011

The fundamental research for the mobile robot navigation using the numerical optimization method is presented. We define the mobile robot navigation problem as an unconstrained optimization problem to minimize the cost function with the pose error between the goal position and the position of a mobile robot. Using the nonlinear least squares optimization method, the optimal speeds of the left and right wheels can be found as the solution of the optimization problem. Especially, the rotational speed of wheels of a mobile robot can be directly related to the overall speed of a mobile robot using the Jacobian derived from the kinematic model. It will be very useful for applying to the mobile robot navigation. The performance was evaluated using the simulation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.12
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• pp.3345-3363
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• 2023

Developers often use cross-platform frameworks to create mobile apps that can run on multiple platforms with minimal code changes. However, these frameworks may not suit all the needs of a specific app, so developers may also use native APIs to add platform-specific features. This method eventually dilutes the advantages of cross-platform development methodology that aims to reduce development costs and time, and often leads to a decision to return back to the original native mobile development methodology. In this study, we explore a different approach: combining different cross-platform tools to develop a storybook mobile app that meets various requirements. We have demonstrated that integrating two cross-platform solutions can be used reliably to develop complex mobile applications. However, we also report that this approach can introduce unforeseen issues such as sandbox redundancy, unexpected functional burdens, and redundant permission requests. Despite these challenges, we believe that combining two cross-platform solutions can be applied to a variety of functional and performance requirements, enabling the development of more sophisticated mobile applications at lower costs and with shorter development timelines than traditional mobile app development methodologies.

• The Journal of Economics, Marketing and Management
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• v.9 no.2
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• pp.1-10
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• 2021

Purpose: In this work, we examine several time series models to predict internet and mobile transaction amount in South Korea, whereas Jeong (2020) has obtained the optimal forecasts for online shopping transaction amount by using time series models. Additionally, optimal forecasts based on the model considered can be calculated and applied to the Corona 19 situation. Research design, data, and methodology: The data are extracted from the online shopping trend survey of the National Statistical Office, and homogeneous and comparable in size based on 46 realizations sampled from January 2007 to October 2020. To achieve the goal of this work, both multiplicative ARIMA model and Holt-Winters Multiplicative seasonality method are taken into account. In addition, goodness-of-fit measures are used as crucial tools of the appropriate construction of forecasting model. Results: All of the optimal forecasts for the next 12 months for two online shopping transactions maintain a pattern in which the slope increases linearly and steadily with a fixed seasonal change that has been subjected to seasonal fluctuations. Conclusions: It can be confirmed that the mobile shopping transactions is much larger than the internet shopping transactions for the increase in trend and seasonality in the future.

• Journal of Internet Computing and Services
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• v.7 no.4
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• pp.79-90
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• 2006

Data broadcasting is an efficient method for disseminating data, and is widely accepted in the database applications of mobile computing environments because of its asymmetric communication bandwidth between a server and mobile clients. This requires new types of concurrency control mechanism to support mobile transactions executed in the mobile clients, which have low-bandwidths toward the server. In this paper, we propose an OCC/DTA (Optimistic Concurrency Control with Dynamic Time-stamp Adjustment) protocol that can be efficiently adapted to mobile computing environments. The protocol reduces communication overhead by using client-side validation procedure and enhances transaction throughput by adjusting serialization order without violating transaction semantics. We show that the proposed protocol satisfies data consistency requirements, and simulate that this protocol can improve the performance of mobile transactions in data broadcasting environments.

• The Journal of the Korea Contents Association
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• v.19 no.9
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• pp.254-261
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• 2019

Electronic payment is a very crucial function in electronic commerce. As electronic commercial transactions develop on a mobile basis, a variety of electronic payment services that can be conveniently used are appearing. In particular, mobile easy payment services improve the user's convenience of payment and give a positive effect on activating online transactions. In this study we investigate empirically the factors influencing the user resistance to mobile easy payment services. Especially, we compares the main acceptance factors of the mobile easy payment services with the main acceptance resistance factors of the services. By doing that, we derive the implications that could contribute to the vitalizations of the mobile easy payment service market. The research model includes "perceived risk" as a main acceptance resistance factor, and "easy of use" and "usefulness" as the main acceptance factors. The relationship among these three factors, "use conflict", and "user resistance" is expressed in the model. We analyze the model by Structural Equation Model. The results proves that all the research hypotheses are adopted except for the impact of "ease of use" on "use conflict", and that users of mobile easy payment services think of "usefulness" more important than "risk".

• Human Ecology Research
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• v.56 no.4
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• pp.391-405
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• 2018

There has been an increasing and widespread use of smartphones to make consumer purchases. Given the stark increases in the sales of business transactions using mobile phones, it is obvious that mobile phones have become major mediums for consumer purchases. Through mobile phones, people can make their purchases anytime, anywhere, which leads their impulse of consumption directly to actual actions of consumption. Consequently, mobile commerce has become widely spread and the competition of the market has intensified. The main findings and implications of this study are as follows. First, it is shown that, among the features of mobile commerce, elements of fun, usefulness, convenience, immediateness, and security affect mobile commerce user satisfaction. Second, among mobile commerce-related consumers' propensity, innovative consumption tendency appears to impact mobile commerce user satisfaction and repurchase intention. Third, recognition of elements in regards to fun, usefulness, convenience, immediateness, and security among features of mobile commerce affect consumers' intention to repurchase mobile commerce. Future recognition for mobile commerce has a direct impact on increasing consumers' repurchase intentions. Last, a higher mobile commerce user satisfaction leads to the higher repurchase intentions.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.9
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• pp.1692-1698
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• 2010

In this paper we use wireless sensor network and ultrasonic sensors to estimate local position of mobile robots, and to navigate it. Ultra sonic sensor is simple and accurate so it is good to use in local estimation and navigation of mobile robots. But to obtain accurate distance of two sensors they need to face each others as possible as they can. To solve this problem we rotate ultra sonic sensor which is attached to robot in 360 degrees and obtain accurate distance. We can estimate precise position of mobile robot by triangulation using obtained distance information. A mobile robot navigates using embedded encoder and compensates its coordinates by ultrasonic sensors. Results of Experiments show proposed method obtains accurate distance between sensors and coordinates of position of robot. And mobile robots can navigate designated path well.

• IEIE Transactions on Smart Processing and Computing
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• v.5 no.4
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• pp.283-288
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• 2016

Optimizing the number of ad clicks is a large-scale learning problem that is central to the multi-billion-dollar mobile advertising industry. There are currently several optimization methods being used, including ad mediation and ad positioning. Recently, researchers have recommended using ad refresh interval as a new method for optimizing mobile advertising. This paper applies that new method to optimize content duration for mobile ads. The result achieved from this optimization study could further increase revenue for mobile advertisers and publishers. This research has high applicability for the growing mobile advertising industry. It also lays out a solid background for future research in this promising area.