Autor: Chen, K. - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Recent advances in mode converters for a mode division multiplex transmission system
Autorzy:: Memon, A. K.
Chen, K. X.
Tematy:: integrated optical device
mode converters
mode division multiplex
optical waveguide; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Powiązania:: https://bibliotekanauki.pl/articles/1818205.pdf Link otwiera się w nowym oknie
Opis:: Adopting mode division multiplex (MDM) technology as the next frontier for optical fiber communication and on-chip optical interconnection systems is becoming very promising because of those remarkable experimental results based on MDM technology to enhance capacity of optical transmission and, hence, making MDM technology an attractive research field. Consequently, in recent years the large number of new optical devices used to control modes, for example, mode converters, mode filters, mode (de)multiplexers, and mode-selective switches, have been developed for MDM applications. This paper presents a review on the recent advances on mode converters, a key component usually used to convert a fundamental mode into a selected high-order mode, and vice versa, at the transmitting and receiving ends in the MDM transmission system. This review focuses on the mode converters based on planar light wave circuit (PLC) technology and various PLC-based mode converters applied to the above two systems and realized with different materials, structures, and technologies. The basic principles and performances of these mode converters are summarized.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: An Experimental Study on Unipolar Induction
Autorzy:: Chen, K.
Li, X.
Hui, Y.
Tematy:: 01.55.+b
03.50.De
06.30.Ka
41.20.Gz; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1030345.pdf Link otwiera się w nowym oknie
Opis:: Unipolar induction phenomenon is a special kind of electromagnetic induction. There are two quite opposite theoretical explanations for this phenomenon, i.e., the N theory and the M theory. The research of unipolar induction has made significant progress, but there is no final conclusion by now. In this paper, an experiment of inversely rotating double Faraday disks and double magnets are designed, and the unipolar induction phenomenon is verified by means of theoretical calculation and experiment. Comparing and analyzing the theoretical calculation and experiment results, our experimental results support the N theory, that is to say, our experiment shows that the magnetic field does not rotate when the magnet rotates.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Measuring fan speed using the impeller tip pressure method
Pomiar prędkości obrotowej wentylatora metodą oznaczania ciśnienia na końcówce wirnika
Autorzy:: Li, Y. M.
Chen, K. Y.
Tematy:: końcówka wirnika
ciśnienie na końcówce wirnika
zmiany ciśnienia
prędkość obrotowa wentylatora
impeller tip
tip-pressure
pressure pulsation
fan speed; Pokaż więcej
Wydawca:: Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Powiązania:: https://bibliotekanauki.pl/articles/348569.pdf Link otwiera się w nowym oknie
Opis:: The accurate measurement of fan speed is impact in the fan performance test experiments. As there is some relationship between the impeller tip pressure pulse frequency and speed of the impeller, the paper proposed a new impeller tip speed measurement method through counter-rotating fan speed measurement studies. The use of pressure sensors, data acquisition cards and programming technologies to measure the speed of reading directly integrated into the previous fan performance automated test systems was also presented. This proves that this is an effective method by comparing the results of the field tests.
Aby wykonać dokładny pomiar prędkości obrotowej wiatraka należy przeprowadzić test jego osiągów. Ponieważ istnieje związek pomiędzy częstotliwością zmian ciśnienia na końcówce wirnika i prędkością obracania wirnika, w niniejszym artykule zaproponowano nową metodę pomiaru prędkości obrotowej końcówki wirnika poprzez badanie pomiaru prędkości obrotowej wentylatora przeciwbieżnego. Przedstawiono również zastosowanie czujników ciśnienia, kart rejestracji danych oraz technologii programistycznych do pomiaru prędkości wskazań zawartych w poprzednich systemach automatycznego testowania osiągów wentylatora. Porównanie wyników prób terenowych dowodzi skuteczności tej metody.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: The Preparation of Soluble Cellouronic Acid Sodium Salt by 4-Acetamide-TEMPO Mediated Oxidation of Ultrasound-Pretreated Parenchyma Cellulose from Bagasse Pith
Autorzy:: Gao, X.
Chen, K.
Zhang, H.
Peng, L.
Tematy:: ultrasonic pretreatment
bagasse pith
parenchyma cellulose
cellouronic acid sodium salt
4-acetamide-TEMPO; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/177150.pdf Link otwiera się w nowym oknie
Opis:: The parenchyma cellulose isolated from bagasse pith was used as an alternative resource for preparation of water-soluble cellouronic acid sodium salt (CAS). The influence of ultrasound treatment on the cellulose was investigated for obtaining CAS by regioselective oxidization using 4-acetamide-TEMPO and NaClO with NaClO₂ as a primary oxidant in an aqueous buffer at pH 6.0. The yield, carboxylate content and polymerization degree (DP) of CAS were measured as a function of ultrasonic power, agitating time and cellulose consistency by an orthogonal test. The ultrasound-treated conditions were further improved by discussion of ultrasonic power, the most important factor influencing the yield and DP. An optimized CAS yield of 72.9% with DP value (DPv) of 212 was found when the ultrasonic strength is 550 W, agitating time is 3 h and cellulose consistency is 2.0%. The oxidation reactivity of cellulose was improved by ultrasonic irradiation, whereas no significant changes in crystallinity of cellulose were measured after ultrasonic treatment. Moreover, the ultrasound treatment has a greater effect on yielding CAS from parenchyma cellulose than from bagasse fibrous’ one. The CAS was further characterized by Fourier transform infrared spectroscopy (FT-IR) and Scanning electron microscopy (SEM).
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Sender-equivocable encryption schemes secure against chosen-ciphertext attacks revisited
Autorzy:: Huang, Z.
Liu, S.
Qin, B.
Chen, K.
Tematy:: sender equivocable encryption
chosen ciphertext attack
cross authentication code; Pokaż więcej
Wydawca:: Uniwersytet Zielonogórski. Oficyna Wydawnicza
Powiązania:: https://bibliotekanauki.pl/articles/330140.pdf Link otwiera się w nowym oknie
Opis:: Fehr et al. (2010) proposed the first sender-equivocable encryption scheme secure against chosen-ciphertext attacks (NCCCA) and proved that NC-CCA security implies security against selective opening chosen-ciphertext attacks (SO-CCA). The NC-CCA security proof of the scheme relies on security against substitution attacks of a new primitive, the “cross-authentication code”. However, the security of the cross-authentication code cannot be guaranteed when all the keys used in the code are exposed. Our key observation is that, in the NC-CCA security game, the randomness used in the generation of the challenge ciphertext is exposed to the adversary. Based on this observation, we provide a security analysis of Fehr et al.'s scheme, showing that its NC-CCA security proof is flawed. We also point out that the scheme of Fehr et al. encrypting a single-bit plaintext can be refined to achieve NC-CCA security, free of the cross-authentication code. Furthermore, we propose the notion of “strong cross-authentication code”, apply it to Fehr et al. 's scheme, and show that the new version of the latter achieves NC-CCA security for multi-bit plaintexts.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Optimal screw orientation for the fixation of cervical degenerative disc disease using nonlinear C3-T2 multi-level spinal models and neuro-genetic algorithms
Autorzy:: Chang, T.-K.
Hsu, C.-C.
Chen, K.-T.
Tematy:: stabilizacja
optymalizacja
kątownik
bioinżynieria
cervical plate
insertion angle
fixation stability
optimization; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/306375.pdf Link otwiera się w nowym oknie
Opis:: Purpose: Anterior cervical discectomy and fusion is a common surgical procedure performed to remove a degenerative or herniated disc in cervical spine. Unfortunately, clinical complications of anterior cervical plate (ACP) systems still occur, such as weak fixation stability and implant loosening. Previous researchers have attempted to ameliorate these complications by varying screw orientations, but the screw orientations are mainly determined according to the investigator’s experiences. Thus, the aim of this study was to discover the optimal screw orientations of ACP systems to achieve acceptable fixation stability using finite element simulations and engineering algorithms. Methods: Three-dimensional finite element models of C3-T2 multi-level segments with an ACP system were first developed to analyze the fixation stability using ANSYS Workbench 14.5. Then, artificial neural networks were applied to create one objective function, and the optimal screw orientations of an ACP system were discovered by genetic algorithms. Finally, the numerical models and the optimization study were validated using biomechanical tests. Results: The results showed that the optimal design of the ACP system had highest fixation stability compared with other ACP designs. The neuro-genetic algorithm has effectively reduced the time and effort required for discovering for the optimal screw orientations of an ACP system. Conclusions: The optimum screw orientation of the ACP system could be successfully discovered, and it revealed excellent fixation stability for the treatment of cervical degenerative disc disease. This study could directly provide the biomechanical rationale and surgical suggestion to orthopedic surgeons.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Afamin and adropin in patients with alcohol-induced liver cirrhosis
Autorzy:: Prystupa, A.
Kiciński, P.
Luchowska-Kocot, D.
Sak, J.
Prystupa, T.
Chen, K.-H.
Chen, Y.-H.
Panasiuk, L.
Załuska, W.
Tematy:: alcoholic liver cirrhosis
Adropin
Child-Pugh score
afamin; Pokaż więcej
Wydawca:: Instytut Medycyny Wsi
Powiązania:: https://bibliotekanauki.pl/articles/2081906.pdf Link otwiera się w nowym oknie
Opis:: The aim of the study was to determine serum concentrations of afamin and adropin in patients with alcoholic liver cirrhosis and to define their correlation with the stage of disease. The study included 99 patients with alcoholic cirrhosis from the region of Lublin, (Eastern Poland). Liver cirrhosis was diagnosed based on clinical features, history of heavy alcohol consumption, laboratory tests and abdominal ultrasonography. The control group consisted of 20 healthy individuals without liver disease who did not abuse alcohol. The serum afamin and adropin concentrations were determined using ELISA kits. The concentration of afamin was found to be significantly lower in patients with compensated alcoholic liver cirrhosis, i.e. P-Ch B (85.1±40.6 μg/ml) and P-Ch C (56.4±32.3 μg/ml) individuals, compared to the control group (135.9±43.6 μg/ml); p-value was <0.01 and <0.001, respectively. As far as adropin is concerned, a reverse relationship was demonstrated: the highest concentration was found in patients with P-Ch C (11.7±5.7 ng/ml) cirrhosis. Furthermore, the above concentration was significantly higher compared to patients with P-Ch A cirrhosis (7.2±2.8 ng/ml; p<0.05) and controls (7.5±2.6 ng/ml; p<0.05). The concentration of afamin decreases with the severity of alcoholic liver cirrhosis, which most likely results from impaired hepatic synthesis. Otherwise, the higher the stage of disease according to the Child-Pugh score, the higher the concentration of adropin.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: A stepwise ISO-based TQM implementation approach using ISO 9001:2015
Autorzy:: Chen, C.-K.
Anchecta, K.
Lee, J. -D.
Dahlgaard, J. J.
Tematy:: Total Quality Management
TQM
ISO QMS
ISO 9000
ISO 9001:2015
international standard; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/407353.pdf Link otwiera się w nowym oknie
Opis:: The lack of an implementation roadmap always deters enterprises from choosing Total Quality Management (TQM) as its major management approach. This paper proposes a stepwise ISO-based TQM implementation approach which is based on the notion of the new threedimensional overall business excellence framework developed by Dahlgaard et al. [1]. The proposed approach consists of nine steps comprising three categories: “TQM faith building”, “TQM tools and techniques learning”, and “system development”. The steps in each of the three categories are arranged to span across the proposed nine-step approach. The ISO 9001:2015 standard is used as a case study to demonstrate the proposed approach. The ideas and benefits of the proposed approach are further discussed in relation to this illustration.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Piecewise reliability-dependent hazard rate for composites under fatigue loading adjustment
Konstrukcja funkcji ryzyka uszkodzeń kawałkami zależnej od niezawodności dla kompozytów poddanych różnym scenariuszom obciążenia zmęczeniowego
Autorzy:: Chen, C.-L.
Wang, K.-S.
Tematy:: fatigue loading adjustment
hazard rate function
dynamical reliability
Monte Carlo simulation
linear damage sum; Pokaż więcej
Wydawca:: Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Powiązania:: https://bibliotekanauki.pl/articles/281955.pdf Link otwiera się w nowym oknie
Opis:: Based on the derived transition period and reliability drop, this paper proposes a method of piecewise combination of the reliability-dependent hazard rate function named (e_ocp) model to describe the dynamical reliability in a two-stage fatigue loading process. First, the parameters e_o, c, p are fitted through simulated failure data under various constant- amplitude cyclic stresses. The reliability of the high-low loading process is described piecewise with the corresponding values of (e_o, c, p) for each respective stress level, and maintains R_a in the transition period while R_a denotes the reliability at which the stress level changes. The reliability of the low-high process is determined by subtracting the portion of reliability drop at R_a from the piecewise fitted curves. The proposed reliability behavior is verified successfully. The linear damage sum is found to be larger than unity for the high-low loading, and on the contrary for the low-high cases. A larger difference between the stress level changed results in larger deviation of damage sum from unity, especially when R_a near 0.9.
W oparciu o wyznaczony okres przejściowy i spadek niezawodności, artykuł prezentuje metodę określania funkcji ryzyka uszkodzenia kawałkami zależnej od poziomu niezawodności, zwanej (e_ocp) i służącej do modelowania dynamicznej niezawodności dla dwustanowych procesów obciążania zmęczeniowego. Na poczatku, parametry e_o, c, i p dopasowano do danych otrzymanych w drodze symulacji uszkodzeń pod wpływem działania cyklicznych naprężeń o kilku stałych amplitudach. Niezawodność dla obciążeń przechodzących od dużej amplitudy do małej opisano kawałkami zależnymi od poziomu przykładanych naprężeń i odpowiadającymi im wartościami e_o, c, i p. Wynosi ona R_a w okresie przejściowym, gdzie R_a jest niezawodnością, przy której poziom naprężeń jest zmieniany. Niezawodność przy obciążeniu rosnącym wyznaczono, odejmując część jej spadku przy R_a od kawałkami dopasowanych krzywych. Zaproponowany sposób opisu niezawodności sukcesywnie weryfikowano. Zaobserwowano, że liniowa suma uszkodzeń przekracza jedność dla scenariusza obciążeń stopniowo malejących i nie osiąga tej wartości w przypadku przeciwnym. Większe różnice w poziomach obciążeń skutkowały w większych odstępstwach liniowej sumy uszkodzeń od jedności. Szczególnie duże zauważono dla R_a = 0.9.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Computational simulation analysis for torus radius of edge contact in hip prostheses
Autorzy:: Li, F.
Chen, H
Mao, K.
Tematy:: staw biodrowy
endoproteza
kontakt Hertza
nacisk kontaktowy
hip prostheses
Hertzian contact
edge torus radius
contact pressure
contact dimensions
inclination angle; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/307414.pdf Link otwiera się w nowym oknie
Opis:: Stripe wear occurs when the components of hip prostheses move a sufficient distance laterally to contact the edge of the acetabular cup, causing abnormally high contact stresses. In this research, edge loading contact of prosthetic hip is analyzed in the most commonly used material pairs. The contact dimensions and maximal contact pressure are investigated in mutative normal edge loading with 3 different inclination angles (15°, 20°, 25°) and in alterable edge torus radius with edge loading of 2500 N and inclination of 20°. A computational case was conducted for a 14 mm radius alumina ceramic bearing with a radial clearance of 0.1 mm using a normal edge loading ranged from 0 N to 3000 N. Additionally, the Hertzian theory successfully captures principal curvature trends of the edge torus on the influence of maximal contact pressure and obtains the appropriate edge radius range for lower maximal contact pressure. This work elucidates the methods of applying classical contact theory to design the edge radius of hip bearings to better resist severe edge loading contact stresses and reduce the stripe wear.
Dostawca treści:: Biblioteka Nauki

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