Korean and Vietnamese User Loyalty: KakaoTalk Case

This research is a comparative study on user loyalty of mobile-instant messaging (MIM) in Korea and Vietnam. In general, this paper aims to find out whether any differences in user behavior and user loyalty for MIM services between Korea and Vietnam. To serve that purpose, the study theoretically bases on the information systems (IS) success model and expectation-confirmation model (ECM) with appropriate adjustments for this research context. The paper collects the survey data on 644 MIM users in Korea and Vietnam, the chosen MIM service is KakaoTalk. The results show that system quality, perceived usefulness and satisfaction strongly influence on loyalty in case of Korean users; whilst system quality, service quality and satisfaction strongly affect to loyalty in case of Vietnamese users. Contributions and implications are discussed. Moreover, the practical MIM strategies built from research findings might give some helpful suggestions to MIM providers in both Vietnamese and Korean market

Galactic Coronae in the Intracluster Environment: Semi-confined Stellar-feedback-driven Outflows

Recently X-ray observations have shown the common presence of compact galactic coronae around intermediate-mass spheroid galaxies embedded in the intracluster/intragroup medium (ICM). We conduct 2-D hydrodynamic simulations to study the quasi-steady-state properties of such coronae as the natural products of the ongoing distributed stellar feedback semi-confined by the thermal and ram pressures of the ICM. We find that the temperature of a simulated corona depends primarily on the specific energy of the feedback, consistent with the lack of the correlation between the observed hot gas temperature and K-band luminosity of galaxies. The simulated coronae typically represent subsonic outflows, chiefly because of the semi-confinement. As a result, the hot gas density increases with the ICM thermal pressure. The ram pressure, on the other hand, chiefly affects the size and lopsidedness of the coronae. The density increase could lead to the compression of cool gas clouds, if present, and hence the formation of stars. The increase also enhances radiative cooling of the hot gas, which may fuel central supermassive black holes, explaining the higher frequency of active galactic nuclei observed in clusters than in the field. The radiation enhancement is consistent with a substantially higher surface brightness of the X-ray emission detected from coronae in cluster environment. The total X-ray luminosity of a corona, however, depends on the relative importance of the surrounding thermal and ram pressures. These environment dependences should at least partly explain the large dispersion in the observed diffuse X-ray luminosities of spheroids with similar stellar properties. Furthermore, we show that an outflow powered by the distributed feedback can naturally produce a positive radial gradient in the hot gas entropy, mimicking a cooling flow.Comment: accepted by MNRAS, comments are welcom

A Deployment Model for Cloud Computing using the Analytic Hierarchy Process and BCOR Analysis

Cloud computing has emerged as a result of continuous development in the field of information technology. It is expected that most of the enterprises will adopt this new computing model in the near future. There are three main deployment models in cloud computing, namely, public, private, and hybrid cloud. To implement the cloud service, enterprises have to choose one of these deployment models. The purpose of this paper is to suggest a decision model for cloud computing deployment. To that end, this paper uses the analytic hierarchy process (AHP) and benefit-cost-opportunity-risk (BCOR) analysis to select the best cloud computing deployment model with a holistic view based on the benefit, cost, opportunity, and risk factors. The results of this study will be useful for managers who have the intention to adopt cloud computing for their organization

Structural parameters and dynamics of lyotropic liquid crystalline phases in hydrated monolinolein

To date, the stability of inverse bicontinuous cubic phases and the mechanism of lamellar to cubic transitions are poorly understood due to limited experimental resolution and reproducibility. Systematic experimental data is imperative for reasonable testing and verification of established theoretical models in this area. This thesis focuses on two aspects of lyotropic phase behaviour; the equilibrium behaviour of lyotropic liquid crystalline phases and the transitions between the equilibrium states. When monolinolein (ML) is mixed with water it forms a variety of inverse lyotropic phases, for example the lamellar, inverse bicontinuous phases (QII G and QII D) and the inverse hexagonal phase (HII) which makes this lipid an ideal candidate for study of these phases. The monolinolein equilibrium phase behaviour has been characterised as a function of pressure, temperature and hydration using SAXS (small angle X-ray scattering) and the data used to verify the existence of the pivotal surface in the QII G phase. Knowing the location of the pivotal surface allows one to calculate the total energy of these structures. The second part of this thesis discusses the kinetics of the lamellar to QII G transition in monolinolein under limited hydration conditions using the pressure jump time resolved X-ray diffraction technique. Lamellar to inverse bicontinuous cubic phase transitions are relevant to fundamental cellular processes such as membrane fusion and fission due to structural similarities of the mechanisms. The sequence of structural changes observed from kinetic experiments are discussed in relation to the Stalk Mechanism and the data analysed using a quantitative model

Predictors of short-term clinical response to cardiac resynchronization therapy

Aims: Cardiac resynchronization therapy (CRT) reduces morbidity and mortality in patients with symptomatic heart failure and QRS prolongation but there is uncertainty about which patient characteristics predict short-term clinical response. Methods and results: In an individual patient meta-analysis of three double-blind, randomized trials, clinical composite score (CCS) at 6 months was compared in patients assigned to CRT programmed on or off. Treatment–covariate interactions were assessed to measure likelihood of improved CCS at 6 months. MIRACLE, MIRACLE ICD, and REVERSE trials contributed data for this analysis (n = 1591). Multivariable modelling identified QRS duration and left ventricular ejection fraction (LVEF) as predictors of CRT clinical response (P < 0.05). The odds ratio for a better CCS at 6 months increased by 3.7% for every 1% decrease in LVEF for patients assigned to CRT-on compared to CRT-off, and was greatest when QRS duration was between 160 and 180 ms. Conclusions: In symptomatic chronic heart failure patients (NYHA class II–IV), longer QRS duration and lower LVEF independently predict early clinical response to CRT

A Cost Analysis of Carpal Tunnel Release Surgery Performed Wide Awake versus under Sedation.

BACKGROUND: Hand surgery under local anesthesia only has been used more frequently in recent years. The purpose of this study was to compare perioperative time and cost for carpal tunnel release performed under local anesthesia ( wide-awake local anesthesia no tourniquet, or WALANT) only to carpal tunnel release performed under intravenous sedation. METHODS: A retrospective comparison of intraoperative (operating room) surgical time and postoperative (postanesthesia care unit) time for consecutive carpal tunnel release procedures performed under both intravenous sedation and wide-awake local anesthesia was undertaken. All operations were performed by the same surgeon using the same mini-open surgical technique. A cost analysis was performed by means of standardized anesthesia billing based on base units, time, and conversion rates. RESULTS: There were no significant differences between the two groups in terms of total operative time, 28 minutes in the intravenous sedation group versus 26 minutes in the wide-awake local anesthesia group. Postanesthesia care unit times were significantly longer in the intravenous sedation group (84 minutes) compared to the wide-awake local anesthesia group (7 minutes). Depending on conversion rates used, a total of $139 to$432 was saved in each case performed with wide-awake local anesthesia by not using anesthesia services. In addition, a range of $1320 to$1613 was saved for the full episode of care, including anesthesia costs, operating room time, and postanesthesia care unit time for each patient undergoing wide-awake local anesthesia carpal tunnel release. CONCLUSION: Carpal tunnel release surgery performed with the wide-awake local anesthesia technique offers significant reduction in cost for use of anesthesia and postanesthesia care unit resources