Heuristic Algorithms for Constructing Interference-Free and Delay-Constrained Multicast Trees for Wireless Mesh Networks

( Wen-lin Yang ),( Chi-chou Kao ),( Cheng-huang Tung ) 한국인터넷정보학회 2011 KSII Transactions on Internet and Information Syst Vol.5 No.2

In this paper, we study a problem that is concerning how to construct a delay-constrained multicast tree on a wireless mesh network (WMN) such that the number of serviced clients is maximized. In order to support high-quality and concurrent interference-free transmission streams, multiple radios are implemented in each mesh node in the WMNs. Instead of only orthogonal channels used for the multicast in the previous works, both orthogonal and partially overlapping channels are considered in this study. As a result, the number of links successfully allocated channels can be expected to be much larger than that of the approaches in which only orthogonal channels are considered. The number of serviced subscribers is then increased dramatically. Hence, the goal of this study is to find interference-free and delay-constrained multicast trees that can lead to the maximal number of serviced subscribers. This problem is referred as the MRDCM problem. Two heuristics, load-based greedy algorithm and load-based MCM algorithm, are developed for constructing multicast trees. Furthermore, two load-based channel assignment procedures are provided to allocate interference-free channels to the multicast trees. A set of experiments is designed to do performance, delay and efficiency comparisons for the multicast trees generated by all the approximation algorithms proposed in this study.

Improved Electron Injection of Organic Light-emitting Diodes by Using an Ultrathin Lithium-hydroxide Buffer Layer

Po-Ching Kao,Shu-I Lin,Chin-Chih Chang,Ching-Wen Huang,Chien-Chi Liu 한국물리학회 2012 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.60 No.10

A cathode buffer layer of lithium hydroxide (LiOH) was used to improve the electro-optical properties of organic light-emitting diodes (OLEDs). LiOH layers with various thicknesses were prepared by thermally evaporating LiOH powders. When a 1-nm-thick LiOH layer was inserted between the aluminum (Al) cathodes and the tris(8-hydroxyquinolinato)aluminum (Alq3) electrontransporting layers, device properties such as the turn-on voltage, the maximum luminance, and the device efficiency were improved, becoming better than those of the device with a LiF buffer layer. The surface of the Alq3 film became smoother after the LiOH layer had been deposited. Ultraviolet photoelectron spectroscopy results show that the reaction between LiOH and Alq3 results in an n-type doping effect, which moves the Fermi level close to the lowest unoccupied molecular orbital (LUMO) of Alq3. Thus, the electron-injection efficiency was enhanced due to a lower electron injection barrier, which improved the charge carrier balance in the OLEDs and led to a better device efficiency.

Serum and Pleural Fluid Procalcitonin in Predicting Bacterial Infection in Patients with Parapneumonic Effusion

Yang-Ching Ko,Wen-Pin Wu,Chi-Sen Hsu,Mong-Ping Dai,Chien-Chih Ou,Chih-Hsiung Kao 대한의학회 2009 Journal of Korean medical science Vol.24 No.3

This study evaluated the value of procalcitonin (PCT) levels in pleural effusion to differentiate the etiology of parapneumonic effusion (PPE). Forty-one consecutive PPE patients were enrolled and were divided into bacterial and non-bacterial PPE. Blood and pleural effusion samples were collected for PCT measurement on admission and analyzed for diagnostic evaluation. PCT of pleural fluid was significantly increased in the bacterial PPE group (0.24 ng/mL) compared to the non-bacterial PPE group (0.09 ng/mL), but there was no significant difference for serum PCT. A PCT concentration of pleural fluid >0.174 ng/mL (best cut-off value) was considered positive for a diagnosis of bacterial PPE (sensitivity, 80%; specificity, 76%; AUC, 0.84). Pleural effusion PCT in the bacterial PPE is significantly different from those of the non-bacterial PPE and control groups, so the diagnostic use of PCT still warrants further investigation.

Validation of a Palliative Prognostic Index to Predict Life Expectancy for Terminally Ill Cancer Patients in a Hospice Consultation Setting in Taiwan

Cheng, Wei-Hong,Kao, Chen-Yi,Hung, Yu-Shin,Su, Po-Jung,Hsieh, Chia-Hsun,Chen, Jen-Shi,Wang, Hung-Ming,Chou, Wen-Chi Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.6

Background: The aim of our study was to assess the practical utility of the palliative prognostic index (PPI) as a prognostic tool used by nurse specialists in a hospice consultation setting in Taiwan. Methods: In total, 623 terminal cancer patients under hospice consultation care from one medical center in northern Taiwan were enrolled between January 1 and June 30, 2011. PPI was assessed by a nurse specialist at first hospice consultation and patients categorized into groups by prognosis (good, intermediate, poor). Patient survival was analyzed retrospectively to determine significance of between-group differences. Results: By PPI sum score, 37.2% of patients were in the good prognosis group, 18% in the intermediate prognosis group and 44.8% in the poor prognosis group. The death rates were 56%, 81.2% and 89.6% and median survivals were 76, 18 and 7 days, respectively. The hazard ratio was 0.19 (95% confidence interval [CI] 0.10-0.24, p<0.001) for the poor versus good prognosis group and 0.54 (95% CI 0.43-0.69, p<0.001) for the poor versus intermediate prognosis group. The sensitivity and specificity for the poor prognosis group was 66% and 71%; the positive predictive value and negative predictive value were 81% and 52%, respectively, to predict patient death within 21 days (area under the curve of the receiver operating characteristic was 0.68). Conclusions: Assessment by PPI can accurately predict survival of terminal cancer patients receiving hospice consultation care. PPI is a simple tool and can be administered by nurse members of hospice consultation teams.

Corpus of Eye Movements in L3 Spanish Reading: A Prediction Model

Hui-Chuan Lu,Li-Chi Kao,Zong-Han Li,Wen-Hsiang Lu,An-Chung Cheng Institute for Corpus Research 2024 Asia pacific journal of corpus research Vol.5 No.1

This research centers on the Taiwan Eye-Movement Corpus of Spanish (TECS), a specially created corpus comprising eye-tracking data from Chinese-speaking learners of Spanish as a third language in Taiwan. Its primary purpose is to explore the broad utility of TECS in understanding language learning processes, particularly the initial stages of language learning. Constructing this corpus involves gathering data on eye-tracking, reading comprehension, and language proficiency to develop a machine-learning model that predicts learner behaviors, and subsequently undergoes a predictability test for validation. The focus is on examining attention in input processing and their relationship to language learning outcomes. The TECS eye-tracking data consists of indicators derived from eye movement recordings while reading Spanish sentences with temporal references. These indicators are obtained from eye movement experiments focusing on tense verbal inflections and temporal adverbs. Chinese expresses tense using aspect markers, lexical references, and contextual cues, differing significantly from inflectional languages like Spanish. Chinese-speaking learners of Spanish face particular challenges in learning verbal morphology and tenses. The data from eye movement experiments were structured into feature vectors, with learner behaviors serving as class labels. After categorizing the collected data, we used two types of machine learning methods for classification and regression: Random Forests and the k-nearest neighbors algorithm (KNN). By leveraging these algorithms, we predicted learner behaviors and conducted performance evaluations to enhance our understanding of the nexus between learner behaviors and language learning process. Future research may further enrich TECS by gathering data from subsequent eye-movement experiments, specifically targeting various Spanish tenses and temporal lexical references during text reading. These endeavors promise to broaden and refine the corpus, advancing our understanding of language processing.

Effect of Hydrodynamic Condition on the Electrochemical Behavior of Various Metals in 3.5 wt% NaCl Solution

( Szu Jung Pan ),( Samuel Sudibyo Hadinata ),( Ruey Chy Kao ),( Wen Ta Tsai ) 한국부식방식학회 2015 Corrosion Science and Technology Vol.14 No.5

The electrochemical behaviors of various metals with and without diamond-like-carbon (DLC) coating in 3.5 wt% NaCl solution were investigated. The effect of hydrodynamic conditions was focused by employing a rotating disc electrode (RDE). The experimental results showed that each bare metal had a more positive corrosion potential and a higher corrosion rate due to enhanced oxygen transport at the higher rotating speed of the RDE. DLC coating caused a substantial increase in the corrosion resistance of all metals studied.However, localized corrosion was still found in the DLC-coated metal at sites where deposition defects existed. Surface morphology examination was performed after the electrochemical test to confirm the roles of hydrodynamic conditions and DLC coating.

Effect of Transplant Timing and Ethylene Inhibitor and Vitamin B₁, Activated Charcoal, Zinic Sulfate, Light Intensity on Phalaenopsis Hybrid in vitro

Ruey-Song Lin,Shu-Fen Hsu,Yu-Hsuan Yang,Szu-Lun Lai,Wen-Chi Kao,Jung-Hua Hsu 한국원예학회 2006 한국원예학회 기타간행물 Vol.- No.-