► Proposed the major characteristics of social commerce (s-commerce). ► Developed the research model empirically testing the effects of those characteristics of s-commerce on consumers’ trust of ...s-commerce. ► Reputation, size, information quality, transaction safety, communication, and word-of-mouth referrals directly affect consumers’ trust of s-commerce. ► Economic feasibility did not have a significant influence on consumers’ trust of s-commerce. ► Trust directly affects two variables (purchase and word-of-mouth intentions) of trust performance.
The development of social networking sites (SNSs) has given rise to a new e-commerce paradigm called social commerce (s-commerce). S-commerce is a subset of e-commerce and uses SNSs for social interactions and user contributions to facilitate the online buying and selling of various products and services. Recent years have witnessed the rapid growth of s-commerce in Korea, but this growth has involved a number of transaction-related issues such as no delivery and the delivery of wrong items. In particular, consumers’ trust has become a crucial factor in the success of s-commerce firms, requiring these firms to make more effort to gain this trust. In this regard, this study identifies the key factors in s-commerce reputation, size, information quality, transaction safety, communication, economic feasibility, and word-of-mouth (WOM) referrals, that is, the characteristics of s-commerce influencing Korean consumers’ trust in s-commerce. In addition, the study assesses the effects of trust on trust performance (purchase intentions and WOM intentions). The results of an empirical analysis based on a sample of 371s-commerce users indicate that all the characteristics of s-commerce (except for economic feasibility) had significant effects on trust and that trust had significant effects on purchase and WOM intentions. The results have important implications for s-commerce firms wishing to develop a successful business model for providing their customers with trustworthy services.
Dimensionless governing equations of unsteady flow and solutions for the pipeline systems having a surge tank were developed. Frequency domain pressure response expressions for two widely used water ...supply systems were analyzed in dimensionless frequency and time domains. One is the simple reservoir pipeline surge tank valve system and the other is the pipeline system with pump and check valve protected by surge tank. Two different dimensionless expressions for the surge tank were developed and the performance of two expressions was compared. The frequency response pattern of impedance at the downstream valve indicated that the system resonance was determined by the lengths of the main pipeline and the connector and the locations of the surge tank and check valve for the protection of the pumping station. The difference between the simple pipeline system and that of a pump with a check valve was expressed in terms of the phase difference in frequency response distribution. The integrated pressure response for the protected pipeline section was evaluated considering the impact of surge protection in the frequency domain. A better understanding of system behavior can be obtained in terms of specific component isolation both in the frequency and time domain pressure responses. The driven responses in the frequency and time domain can be an important basis for optimum design and operation conditions of water supply systems in dimensionless space.
The claims data of the Health Insurance Review and Assessment Service (HIRA) is an important source of information for healthcare service research. The claims data of HIRA is collected when ...healthcare service providers submit a claim to HIRA to be reimbursed for a service that they provided to patients. To improve the accessibility of healthcare service researchers to claims data of HIRA, HIRA has developed the Patient Samples which are extracted using a stratified randomized sampling method. The Patient Samples of HIRA consist of five tables: a table for general information (Table 20) containing socio-demographic information such as gender, age and medical aid, indicators for inpatient and outpatient services; a table for specific information on healthcare services provided (Table 30); a table for diagnostic information (Table 40); a table for outpatient prescriptions (Table 53) and a table for information on healthcare service providers (Table of providers). Researchers who are interested in using the Patient Sample data for research can apply via HIRA's website (https://www.hira.or.kr).
Here we report a fully flexible, foldable nanopatterned wearable triboelectric nanogenerator (WTNG) with high power-generating performance and mechanical robustness. Both a silver (Ag)-coated textile ...and polydimethylsiloxane (PDMS) nanopatterns based on ZnO nanorod arrays on a Ag-coated textile template were used as active triboelectric materials. A high output voltage and current of about 120 V and 65 μA, respectively, were observed from a nanopatterned PDMS-based WTNG, while an output voltage and current of 30 V and 20 μA were obtained by the non-nanopatterned flat PDMS-based WTNG under the same compressive force of 10 kgf. Furthermore, very high voltage and current outputs with an average value of 170 V and 120 μA, respectively, were obtained from a four-layer-stacked WTNG under the same compressive force. Notably it was found there are no significant differences in the output voltages measured from the multilayer-stacked WTNG over 12 000 cycles, confirming the excellent mechanical durability of WTNGs. Finally, we successfully demonstrated the self-powered operation of light-emitting diodes, a liquid crystal display, and a keyless vehicle entry system only with the output power of our WTNG without any help of external power sources.
•Hydrological connectivity of soil moisture is employed in the modeling.•Representation points were identified and used to predict soil moisture.•A hillslope wetness index shows threshold behavior in ...model predictability.
Observation of temporal variations in soil moisture along transects is important when examining hydrological processes on a hillslope. Although there is substantial interest in characterizing catchment hydrology through an investigation of hydrologic connectivity, few attempts have been made to explore hydrologic connectivity within soil layers using soil moisture observations. Mathematical relationships among soil moisture differences are reproducible when Granger causality is defined within the context of hydrological connectivity because the process based transfer functions facilitate soil moisture predictions. Soil moisture time series along two transects on a steep hillslope were obtained using a multiplexed time domain reflectometry system during the growing season in June 2008 and 2009. The transfer function relationships between multiple soil moisture differences were delineated to determine a representative point for reliable time series modeling, and to establish the spatial pattern of areal clusters that will enable model identification and prediction. The impact of hillslope topography on the modeling of coupled soil moisture was highlighted by configuring the threshold behavior of model predictability. Results showed that soil moisture temporal relationships can be used for the prediction of volumetric soil moisture, within a specific area associated with representation point. Reliable relationships among soil moistures were apparent for points having greater upslope areas between 400m2 and 1000m2.
In this study, the results of intensive soil moisture monitoring and analysis are reported in order to highlight the seasonal differences in hydrological processes on a hillslope scale. A soil ...monitoring system for a steep hillslope was designed and installed to monitor the temporal features of soil moisture with respect to the terrain attributes. Comparison of soil moisture analyses for two different periods, one during late autumn and the other during late spring, yielded different soil moisture characteristics, even though both seasons were subject to similar rainfall and saturation conditions. Comparative analyses indicated that soil moisture response patterns can be characterized and classified into three different zones. A substantial portion of the rainfall contributed to recharge of the water storage in autumn, while soil moisture responses were less variable during spring. Infiltration patterns between the two seasons were significantly different, hence the different distribution of soil moisture and hydrological responses. Vertical flux and recharge were the requirements for lateral redistribution of soil moisture in the study area. The seasonal impact of the vegetation, such as transpiration, fine root density, and interception, is apparent on the soil moisture distribution on the hillslope scale as well as runoff features in the mountainous forest catchment.
Since 1992, porcine epidemic diarrhea virus (PEDV) has been one of the most common porcine diarrhea-associated viruses in South Korea. We conducted a large-scale investigation of the incidence of ...PEDV in pigs with diarrhea in South Korea and consequently identified and characterized a novel PEDV variant with a large genomic deletion.
The design of surge protection devices is a practical issue for the management of pressurized pipeline systems. Depending on the flow status, dimension, material, and fluid properties of a particular ...pipeline, the generation of hydraulic transients and their interactions with surge protection devices have been explored considering different conditions for various pipeline systems. The resonance between the pipeline elements and surge energy absorption function of the hydraulic structure should be adaptively considered for each pipeline system. To comprehensively address surge generation and surge alleviating process, this study introduced dimensionless equations of fluid motion and continuity, and their solutions were developed in the dimensionless frequency domain. The impact of the surge tank, pressure accumulator, and its connector were also developed in terms of dimensionless operators. The impact of distinct flow conditions and pipeline properties was successfully addressed by an integrated parameter, dimensionless resistance, which also provided a unified condition for water hammer similarity in reservoir pipeline surge tank pipeline valve (RPSPV) systems. The development of dimensionless hydraulic impedance expressions along a pipeline system and its conversion into a response function provides a normalized pressure response in the dimensionless time domain. Excellent agreement was found between transient simulations using the developed method and those obtained using existing methods. The integration of a dimensionless approach into a metaheuristic engine provides a general platform for surge tank (ST) design in the comprehensive bounds of flow and pipeline conditions.
Wireless virtual reality (VR) is a promising direction for future VR systems that offloads heavy computation to a remote processing entity and wirelessly receives high-quality streams. WiGig and WiFi ...are representative solutions to implement wireless VR; however, they differ in communication bandwidth and reliability. Our testbed experiments show that the performance of WiGig and VR traffic generation strongly correlates with and consequently can be predicted from a user's motion. Based on this observation, we develop a wireless VR system that exploits the benefits of both links by switching between them and controlling the VR frame encoding for latency regulation and image quality enhancement. The proposed system predicts the performance of the links and selects the one with a higher capacity in an opportunistic manner. It adjusts the encoding rate of the host based on the motion-aware prediction of the frame size and estimated latency of the selected link. By evaluating the testbed data, we demonstrate that the proposed system outperforms a WiGig-only system with a fixed encoding rate in terms of latency regulation and image quality.
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