Browsing by Author "Chen, Po-Yu"

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A Load-Balanced Guiding Navigation Protocol in Wireless Sensor Networks
(2008)
Chen, Wen-Tsuen
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Chen, Po-Yu
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Wu, Cheng-Han
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Huang, Chi-Fu
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資訊工程學系
One of the major applications of wireless sensor networks is guiding navigation service with its goal to assist moving objects in leaving a hazardous region safely and quickly. In this paper, we propose a distributed guiding navigation protocol that can guide moving objects to multiple exits with load balancing among multiple navigation paths to the exits. With the assistances of sensor nodes, moving objects are guided to different navigation paths so that they can move to exits as soon as possible without causing congestion. In some traditional navigation algorithms, a sensor may select a wrong guiding direction when an information-updating packet has not flooded through the whole network. Hence, the guiding direction of the sensor may oscillate in a short time and guided objects will confuse with this phenomenon, called direction oscillation problem. This problem will be eliminated in our proposed protocol. Simulation results indicate that our protocol can guide moving objects to exits in shorter time and solve the direction oscillation problem effectively.
Analysis of critical factors for social games based on extended technology acceptance model: a DEMATEL approach
(2018-01-01)
Chang, Chia-Chi
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Chen, Po-Yu
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交大名義發表
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National Chiao Tung University
In recent years, social games such as Farmville' and Pokemon Go' have become a major game type in the gaming industry. This study examines the importance of different factors in social games using the Technology Acceptance Model (TAM) and DEMATEL. The result shows social norm' as the most important factor overall. It is also found that pleasure' and sociability' are the most important aspects in perceived enjoyment'. Regarding key aspects in each factor, flow experience' is crucial in perceived attractiveness', game fairness' largely influential in social norm', and reputation of platform and service provider' a decisive aspect in platform service and corporate image'. These findings and analyses are apt references for social game providers to improve their services.
k-Angle Object Coverage Problem in a Wireless Sensor Network
(2012-12-01)
Tseng, Yu-Chee
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Chen, Po-Yu
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Chen, Wen-Tsuen
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資訊工程學系
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Department of Computer Science
One of the fundamental issues in sensor networks is the coverage problem, which reflects how well a field is monitored or tracked by sensors. Various versions of this problem have been studied, such as object, area, barrier, and hole coverage problems. In this paper, we define a new k-angle object coverage problem in a wireless sensor network. Each sensor can only cover a limited angle and range, but can freely rotate to any direction to cover a particular angle. Given a set of sensors and a set of objects at known locations, the goal is to use the least number of sensors to k-angle-cover the largest number of objects such that each object is monitored by at least k sensors satisfying some angle constraint. We propose centralized and distributed polynomial-time algorithms to solve this problem. Simulation results show that our algorithms can be effective in maximizing coverage of objects. A prototype system is developed to demonstrate the usefulness of angle coverage.
Low Cost All-Dielectric Thin-Film Solar Cell Using Diffuse Medium Reflectors
(2014)
Tseng, Chi Wei
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Fu, Sze Ming
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Lai, Shih-Yun
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Lai, Wei-Ming
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Yan, Sheng Lun
Diffuse reflectors can be beneficial for solar cells, due to no plasmonic loss, higher reflectance, decent light scattering, and low cost. Experimental and theoretical works are presented here to demonstrate its feasibility for photovoltaics.
Mechanical stretch induces hair regeneration through the alternative activation of macrophages
(2019-04-03)
Chu, Szu-Ying
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Chu, Chih-Hung
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Hsien-DaHuang
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Yen, Meng-Hua
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Hong, Hsiao-Chin
Tissues and cells in organism are continuously exposed to complex mechanical cues from the environment. Mechanical stimulations affect cell proliferation, differentiation, and migration, as well as determining tissue homeostasis and repair. By using a specially designed skinstretching device, we discover that hair stem cells proliferate in response to stretch and hair regeneration occurs only when applying proper strain for an appropriate duration. A counterbalance between WNT and BMP-2 and the subsequent two-step mechanism are identified through molecular and genetic analyses. Macrophages are first recruited by chemokines produced by stretch and polarized to M2 phenotype. Growth factors such as HGF and IGF-1, released by M2 macrophages, then activate stem cells and facilitate hair regeneration. A hierarchical control system is revealed, from mechanical and chemical signals to cell behaviors and tissue responses, elucidating avenues of regenerative medicine and disease control by demonstrating the potential to manipulate cellular processes through simple mechanical stimulation.
Providing Group Tour Guide by RFIDs and Wireless Sensor Networks
(2009-06-01)
Chen, Po-Yu
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Chen, Wen-Tsuen
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Tseng, Yu-Chee
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Huang, Chi-Fu
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資訊工程學系
This paper proposes a new application framework for group tour guiding services based on RFIDs and wireless sensor networks. We consider a sensing field mixed with multiple independent tourist groups, each with a leader and several members. Members of a group will follow the moving path of their leader, but may occasionally roam around randomly on their own interests. Sensor nodes have to track leaders' locations and maintain guiding paths from members to leaders. A member may inquire where his/her leader is, and a leader may "recall" his/her members. We propose a feasible solution to such an application by using existing technologies and off-the-shelf components. A group guiding protocol is presented. The design enables reliable group guiding at low-cost and low traffic load. Our prototyping system is reported and system performance is discussed.
Sensitivity evaluation of rhodamine B hydrazide towards nitric oxide and its application for macrophage cells imaging
(2011-12-05)
Wu, Chi-Ming
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Chen, Yen-Hao
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Dayananda, Kasala
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Shiue, Tsun-Wei
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Hung, Chen-Hsiung
A colorless and non-fluorescent rhodamine derivative, rhodamine B hydrazide (RH), is applied to detect nitric oxide and form fluorescent rhodamine B (RB). The reaction mechanism of RH with NO is proposed in this study. The probe shows good stability over a broad pH range (pH > 4). Furthermore, fluorescence intensity of RH displays an excellent linearity to the NO concentration and the detection limit is as low as 20 nM. A 1000-fold fluorescence turn-on from a dark background was observed. Moreover, the selectivity study indicated that the fluorescence intensity increasing in the presence of NO was significantly higher than those of other reactive oxygen/nitrogen species. In exogenously generated NO detection study, clear intracellular red fluorescence was observed in the presence of S-nitroso-N-acetyl-D,L-penicillamine (SNAP, a kind of NO releasing agent). In endogenously generated NO detection study, increasing incubation time of RH with lipopolysaccharied (LPS) pre-treated cells could obtain a highly fluorescent cell image. These cell imaging results demonstrated that RH can efficiently penetrate into Raw 264.7 cells and be used for detection of exogenously and endogenously generated nitric oxide. (C) 2011 Elsevier B.V. All rights reserved.
The Analysis of Service Acceptance Framework for Social Games Based on Extensive Technology Acceptance Model
(2010)
Chen, Po-Yu
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Chang, Chia-Chi
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管理科學系
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Department of Management Science
The social networking website has been one of the most popular Internet websites in recent years. Lately social games such as "happy farm" drew a lot of attentions and accumulated millions of players in short period of time. The popularity of social games is changing the ecosystem of online games. Companies in this industry have to be concerned about the impact of it to keep their competitiveness. Technology acceptance model (TAM) has been pervasively used by researchers in that this model systematically helps the users to find out the process of user behaviors, and explores the impact of external variables which change the attitude and desire of users to adopt new technologies. This study reviewed the behaviors of social game players and used "perceived enjoyment", "perceived attractiveness", "social norms", and "platform service and corporate image" as the external variables and "intention toward playing social games", "customer preference", "customer loyalty" as the dependent variables in the TAM for social games. DEMATEL is used as the analysis tool in this study. The result shows that "social norms" and "perceived enjoyment" are the top two factors that can help to improve the popularity of social games. This study provides a reference to the companies in social game business and helps them to offer a more popular social game to players.
The Coupled Electrical-Optical Simulation of Solar Cell J-V Degradation with Grating Heights
(2014)
Lin, Yu Chiun
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Zhong, Yan-Kai
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Fu, Sze Ming
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Tseng, Chi Wei
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Lai, Shih-Yun
Solar cell with grating structure is used frequently for increased optical absorption, but it can lead to electrical degradation. Here coupled simulation is conducted to clarify the physical reason causing this J-V degradation.
When Integration Works Better than Segregation Does in Multiple-Gain Situations: The Revised Coding Rules in Mental Accounting
(2014-01-01)
Chang, Chia-Chi
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Chen, Po-Yu
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管理科學系
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Department of Management Science
Mental accounting based on the S-shape value function in prospect theory has been widely accepted since it was posited. The coding rules in mental accounting (CRMA) further suggest that segregating gains in multiple-gain situations and aggregating losses (to one big loss) in multiple-loss situations are preferred. CRMA have been then successfully applied to many fields. However, in our daily life, we can find occasions when people tend to aggregate gains in multiple-gain situations (accumulate small money from colleagues for a bigger wedding gift) or segregate losses in multiple-loss situations (phase a monthly donation amount to a smaller daily amount). The only study to date showing experiment results conflicting to CRMA, though, focuses on comparing the utility losses of two losses that happen on the same day and on different days. In this study, in order to resolve the inconsistency, we replicate Thaler\'s experiments with different dollar amounts used in both gain and loss scenarios and propose that mental threshold could be the major reason why in some situations CRMA may not be applicable. Our results show that in multiple-gain (or multiple-loss) situations, CRMA reverse when the accumulated gain (or loss) is over people\'s mental threshold while the individual gains (or losses) are not. Another finding is that in prior-gain or prior-loss situations, the original reference points can serve as a natural mental threshold. When the accumulated gain (or loss) of multiple gains (or losses) is over the original reference point (anchored by prior gains or losses) while the individual gains (or losses) are not, our experiment results show that people\'s preference on segregating gains and aggregating losses is reduced.
Which maximizes donations: Charitable giving as an incentive or incentives for charitable giving?
(2019-04-01)
Chang, Chia-Chi
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Chen, Po-Yu
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交大名義發表
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National Chiao Tung University
With charitable donations becoming a conventional norm, companies may choose to donate their products to improve public image and increase product visibility. Using two donation types (donation-for-gift/charity sale) and two product types (hedonic/utilitarian), this research discusses how charities should frame product-for-money activities toward enhancing compliance and re-donation intentions upon receiving product donations. Two 2 (donation types) by 2 (product types) between-subject experiments are conducted in college campus cafeterias. The first study uses an inspiring cause while the second study provides a scenario designed to evoke sympathy. Results show that donation-for-gift garners higher donation intentions compared to charity sale, as explained by the dual-process model. It is also revealed that product type moderates the influence of donation type on donation intention only when a sympathetic appeal is used. The fitting issue between product type and cause appeal, along with the licensing effect are presented to explain this finding.