Measurement arrangement for the estimation of path loss exponent in wireless sensor network

Path loss model is generally used to relate distance and signal strength in wireless applications. This has been widely implemented in ranging, localization, and location tracking systems. A range of extension models have been proposed to enhance the performance for various environments and applications. Nevertheless, path loss exponent remains its significance as the main factor in the model regardless of how the model is varied. Based on the nature as an exponent of the model, inaccurate path loss exponent amplifies the error if it is used to estimate distance from received signal strength. Therefore, measurement of accurate value for path loss exponent becomes very important as it directly influences the output of distance estimation. Researchers have been studying the methods of measuring accurate path loss exponent in various environments. Instead of emphasizing the calculation process, this paper focuses more on the allocation of transmitters and receivers, and the arrangement among them. From the results obtained from experiments, properly arranged transmitter and receiver nodes provides better estimation of the path loss exponent. Based on the results, this paper also proposes a suitable nodes arrangement scheme for path loss exponent estimation

Accuracy and stability analysis of path loss exponent measurement for localization in wireless sensor network

In wireless sensor network localization, path loss model is often used to provide a conversion between distance and received signal strength (RSS). Path loss exponent is one of the main environmental parameters for path loss model to characterize the rate of conversion. Therefore, the accuracy of path loss exponent directly influences the results of RSS-to-distance conversion. When the conversion requires distance estimation from RSS value, small error of measured path loss exponent could lead to large error of the conversion output. To improve the localization results, the approaches of measuring accurate parameters from different environments have become important. Different approaches provide different measurement stabilities, depending on the performance and robustness of the approach. This paper presents four calibration approaches to provide measurements of path loss exponent based on measurement arrangement and transmitter/receiver node’s allocation. These include one-line measurement, online-update spread locations measurement, online-update small-to big rectangular measurement, and online-update big-to-small rectangular measurement. The first two are general approaches, and the last two are our newly proposed approaches. Based on our research experiments, a comparison is presented among the four approaches in terms of accuracy and stability. The results show that both online-update rectangular measurements have better stability of measurements. For accuracy of measurement, online-update big-to-small rectangular measurement provides the best result after convergence

Cultural Discourse in Taiwan. Ed. Chin-Chuan Cheng, I-Chun Wang, and Steven Tötösy de Zepetnek.

The collected volume Cultural Discourse in Taiwan — edited by Chin-Chuan Cheng, I-Chun Wang, and Steven Tötösy de Zepetnek and published by National Sun Yat-sen Uiniversity Press in 2009 — is intended as an addition to scholarship in the field of Taiwan Studies. The articles in the volume are in many aspects comparative and the topics discussed are in the context of literary and culture scholarship. At the same time, the volume is interdisciplinary as the articles cover historical perspectives, analyses of texts by Taiwan authors, and cultural discourse as related to Taiwan consciousness, language, and linguistic issues. Copyright release to the authors

Hotel service recovery and service quality: Influences of corporate image and generational differences in the relationship between customer satisfaction and loyalty

As the number of tourists continues to grow globally, the hospitality industry players inevitably face more challenges. High competition among the competitors and the emergence of new technologies such as online booking platforms make the competition more intense among players in the hospitality sector. The quality of services provided is undoubtedly crucial to the success of the hotel. Hence, any service failure has to be addressed appropriately in order to maintain a high level of customer satisfaction and to keep the image of the hotel intact. It is therefore vital that service recovery programs are carefully planned to meet various types of service failures which may inevitably occur. In this study, questionnaires were distributed to customers who had experienced service failures. The aim was to investigate the influence of service quality and service recovery on satisfaction and, ultimately, the effect on customer loyalty. The research also tested the mediating effect of corporate image between the relationship of customer satisfaction and customer loyalty. The findings showed that both service recovery and service quality had a significant impact on customer satisfaction. Similarly, it was found that customer satisfaction induced customer loyalty towards the hotel operator. The result also showed that corporate image mediated partially between the relationship of customer satisfaction and customer loyalty

Lymphangiomatous macroglossia associated with extensive cervicomediastinal cystic hygromas

AbstractChildren with lymphangiomatous macroglossia often have difficulty eating and talking, and their airways may be compromised because of bleeding and infection, especially when extensive cervicomediastinal cystic hygromas are present. We report a case of lymphangiomatous macroglossia associated with extensive cystic hygromas in the cervicomediastinal region. The 3-year-old girl was treated with anterior wedge reduction of the tongue, needle aspiration of the cervicomediastinal cystic hygromas, and systemic steroids and antibiotics. The extensive cystic cervicomediastinal hygromas spontaneously regressed, and further surgery was not needed until 4 years later. Surprisingly, subtotal or partial lymphatic malformation removal improved the complicated lymphatic malformation

Service recovery, customer satisfaction and customer loyalty: Evidence from Malaysia’s hotel industry

Purpose – The purpose of this study is to investigate the impact of service recovery dimensions on customer satisfaction and, subsequently, on customer loyalty in the context of the hotel industry. Design/methodology/approach – A self-administered questionnaire was distributed to 500 respondents who had the experiences of staying in the hotels in Malaysia. The structural equation modelling technique was used to study the relationship between the model and the developed hypotheses. Findings – The findings revealed that service recovery dimensions are significantly related to customer satisfaction and have a positive relationship between customer satisfaction and customer loyalty. Practical implications – As the main sector in the hospitality business, hotels play a vital role in the tourism industry. Therefore, the developments in tourism and hotels go hand in hand, as they are mutually dependent on each other. With significant yearly developments in the tourism industry and at a constant rate, hotel operators should reconsider their business strategies to achieve customer loyalty and sustain their businesses. In view of that, the findings of this study not only benchmarks better hotel services but also provides an improved understanding of service recovery that will effectively aid hotel operators in handling service failures; otherwise, customer dissatisfaction may occur if poor service recovery strategies are implemented. Originality/value – The intense competition in the service industry has driven companies to place extra attention on service recovery so as to ensure continuous success. With a yearly significant development in the tourism industry at a constant rate, hotel providers (one of the major beneficiaries) are driven to reconsider their business strategies to achieve customer loyalty and sustain their business

Extensive Reading with Guidance

A language learning mode called “word-focused extensive reading” has been proposed to facilitate word-usage learning. The user inputs a word in the computer program designed and implemented for reading to find its usage in the context of a sentence. The computer program then searches for the knowledge base for the word and provides guidance to show a summary of the salient features of word collocation. Sentences with the word in question are displayed one at a time. For each sentence the relevant collocating words are highlighted. In this way the reader sees the word collocation so as to recognize the salient features of the word and thus incrementally acquires the knowledge of word usage. The program works with large Chinese and English collections of texts. For Chinese the knowledge of word collocation was built on the basis of the Balanced Corpus of Academia Sinica. The English collocation features were collected from the British National Corpus. The program can also be useful for learning to differentiate near-synonyms

Multistep Hybrid Iterations for Systems of Generalized Equilibria with Constraints of Several Problems

We first introduce and analyze one multistep iterative algorithm by hybrid shrinking projection method for finding a solution of the system of generalized equilibria with constraints of several problems: the generalized mixed equilibrium problem, finitely many variational inclusions, the minimization problem for a convex and continuously Fréchet differentiable functional, and the fixed-point problem of an asymptotically strict pseudocontractive mapping in the intermediate sense in a real Hilbert space. We prove strong convergence theorem for the iterative algorithm under suitable conditions. On the other hand, we also propose another multistep iterative algorithm involving no shrinking projection method and derive its weak convergence under mild assumptions

Triple Hierarchical Variational Inequalities with Constraints of Mixed Equilibria, Variational Inequalities, Convex Minimization, and Hierarchical Fixed Point Problems

We introduce and analyze a hybrid iterative algorithm by virtue of Korpelevich's extragradient method, viscosity approximation method, hybrid steepest-descent method, and averaged mapping approach to the gradient-projection algorithm. It is proven that under appropriate assumptions, the proposed algorithm converges strongly to a common element of the fixed point set of infinitely many nonexpansive mappings, the solution set of finitely many generalized mixed equilibrium problems (GMEPs), the solution set of finitely many variational inequality problems (VIPs), the solution set of general system of variational inequalities (GSVI), and the set of minimizers of convex minimization problem (CMP), which is just a unique solution of a triple hierarchical variational inequality (THVI) in a real Hilbert space. In addition, we also consider the application of the proposed algorithm to solve a hierarchical fixed point problem with constraints of finitely many GMEPs, finitely many VIPs, GSVI, and CMP. The results obtained in this paper improve and extend the corresponding results announced by many others

Outcome for self-expandable metal stents in patients with malignant gastroduodenal obstruction: A single center experience

SummaryBackgroundMalignant gastric outlet obstruction causes significant malnutrition and morbidity. The implantation of a metallic stent is an alternative palliative treatment to allow the intake of food in these patients.Patients and MethodsThirty-eight consecutive patients with malignant gastric outlet obstruction who had received an uncovered metallic stent placement in our department from April 2010 to April 2012 were enrolled for analysis. The mean follow-up time was 6.3 months. Food intake, measured by the Gastric Outlet Obstruction Scoring System, complications, duration of stent patency, and survival were evaluated.ResultsThe technical and clinical success rates of the procedure were 100% and 94.7%, respectively. The Gastric Outlet Obstruction Scoring System scores were significantly improved at 1 day, 7 days, and 30 days after the implantation compared with those prior to the procedure (p < 0.001). Aspiration pneumonia developed in two patients (5.2%) after the procedure. One of these patients developed respiratory failure and died 3 days later. Stent dysfunction developed in 11 of 38 patients (28.9%) during the follow-up period; one patient (2.6%) experienced migration of the stent 38 days later due to resolution of the stricture; 10 patients (26.3%) had stent restenosis. The median time of stent patency was 120 days. The presence of peritoneal carcinomatosis when the procedure was carried out was a significantly poor predictive factor of stent patency [hazard ratio (HR) 7.9, p = 0.039]. The median survival of the patients was 156 days. Poor performance status ≥3; HR 2.647, p = 0.012) and nongastric cancer origin (HR 3.466, p = 0.008) were associated with a significantly short survival time.ConclusionMetallic stent placement is an effective and relatively safe treatment for patients with malignant gastric outlet obstruction