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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
341

會計師執行財務報表查核時偵出舞弊責任的認知研究

廖基宏, Liao,Chi-Hung. Unknown Date (has links)
每當重大舞弊案件發生時,社會大眾常將矛頭指向負責財務報表查核的會計師,認為會計師並沒有負起他(她)應負的責任,在國際上,如安隆案(Enron)、世界通訊(Worldcom)的隱瞞虧損、線上時代華納(AOL Time Warner)的虛報廣告營收等等事件皆是如此;在我國,也有赫赫有名的博達等案。 會計師的專業與超然獨立的立場,使得簽證功能得到資訊使用者的信任,對投資大眾而言,亦提供一層重要的保障。然而,會計師所提供之合理確信並非絕對之保證,一旦因為某些無法控制之因素造成企業失敗,相關利害關係人無可避免地會將矛頭指向會計師,因此跟隨而來的訴訟將對會計師造成相當大的損失,而利害關係人與會計師的認知差距即為造成訴訟的關鍵因素。 本研究先探討會計師查核舞弊的責任為何?再進一步研究財務報表使用者與會計師間,對於會計師執行財務報表查核時,偵測舞弊責任的認知,同時研究不同人之間,是否存有認知差距。 本研究採透鏡模型觀念,針對學過及未學過審計學的人進行問卷調查,研究結果發現:受試者皆認為會計師負有偵測管理舞弊的責任,財務報表使用者與會計師之間的認知,雖然使用的線索相同,但線索使用的程度仍有不同。 關鍵字:舞弊、會計師責任、透鏡模型 / Every time when there is serious fraud, the public will accuse the audit accountant for not taking the responsibility he/she should take. Internationally, there are Enron and Worldcom concealed their loses, AOL Time Warner overstated their commercial revenues. In Taiwan, there are also cases like procomp. Due to the profession and independence of accountants, the public trusts the opinion they issued toward the financial statements. However, the assurance that the audit accountant provides is highly but not absolute guarantee. Once there is some incontrollable factors lead to business failure, the interested party will blame the audit accountants. Therefore, the follow-up lawsuit will cause a lot loses to the accountant. The gap between interested party and accountant will be the key point to the lawsuit. The study tries to analyze the viewpoints of the interested party and accountants toward the accountant duty of inspecting fraud when auditing financial statements. The study uses questionnaire, taking national university graduated and college students as objects, and discuss by the framework of lens model. The study concluded that all the interviewee think that the audit accountant has the responsibility to examine the fraud. As to the perception of interested party and accountants, on the other hand, though the interest party and accountant own the same clues, they use them to different extent.
342

Estimation of the mechanical properties of soft tissues using a laser-induced microbubble interrogated by acoustic radiation force

Yoon, Sangpil 13 July 2012 (has links)
This dissertation introduces a new approach to measure the mechanical properties of soft tissues. A laser-induced microbubble, created by focusing a single nanosecond laser pulse with a custom-made objective lens, was created at desired locations inside a tissue sample. An acoustic radiation force was generated by a low frequency transducer to displace the microbubble. A custom-built high pulse repetition frequency (PRF) ultrasound system, consisting of two 25 MHz single element transducers, was used to track the dynamics of the microbubble. Reconstruction of the mechanical properties at the specific location in a tissue sample was performed using a theoretical model, which calculated the dynamics of a microbubble under an externally applied force in a viscoelastic medium. The theoretical model and the high PRF ultrasound system were successfully validated in both gelatin phantoms and ex vivo bovine crystalline lenses. Age-related sclerosis of the crystalline lenses from bovine was clearly detected, which might be linked to changes in the crystalline. Location-dependent variation explained that the outer cortex and the inner nucleus had different mechanical properties. In the old and young porcine vitreous humors, age-related changes were not found. However, local variations of the mechanical properties were discovered, which may coincide with the different distributions of the molecular compositions. The laser-induced microbubble approach shows potential for future research into the origin of physiological phenomena and the development of inherent disorders in the eye. I hope that further studies – in the development of a more suitable theoretical model for the microbubble dynamics, in extension to in vivo applications, and in defining the relationship of the mechanical properties to molecular components in the eye – may provide a plan for the therapeutic treatment of eye-related diseases. / text
343

Novel Broadband Direction of Arrival Estimation Using Luneburg Lens

Yu, Xiaoju, Liang, Min, Sabory-Garcia, Rafael 10 1900 (has links)
ITC/USA 2012 Conference Proceedings / The Forty-Eighth Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2012 / Town and Country Resort & Convention Center, San Diego, California / A broadband passive direction finding system utilizing Luneburg lens has been investigated. With the simulated power level distribution at the detectors mounted on a Luneburg lens, both Cramér-Rao bound (CRB) and the root mean square error (RMS) based on the Correlation Algorithm (CA) for the direction of arrival (DoA) estimation have been derived and calculated. Guidelines on how to design the Luneburg lens detecting system have been studied. Finally, as a proof-of-concept demonstration, the DoA performance of a Luneburg lens fabricated using the polymer jetting technology with five detectors 10° equally spaced to receive the azimuth signal from -20° to 20° is demonstrated.
344

Λειτουργική και αισθητική ένταξη συστημάτων αξιοποίησης της ηλιακής ενέργειας στα κτίρια / Building integration of solar energy systems regarding practical and aesthetacal aspects

Σιαμπέκου, Χριστιάνα 28 June 2007 (has links)
Στην παρούσα εργασία μελετήθηκαν βιβλιογραφικά οι ενεργειακές και αισθητικές παράμετροι που συμβάλλουν στην εξοικονόμηση ενέργειας στον κτιριακό τομέα. Παράλληλα έγινε πειραματική μελέτη μιας καινοτόμου προτεινόμενης διάταξης με φακούς Fresnel για τον έλεγχο του φωτισμού και της θερμοκρασίας των εσωτερικών χώρων των κτιρίων, καθώς και τριών πειραματικών διατάξεων θερμικών ηλιακών συλλεκτών με σκοπό την εκτίμηση της απόδοσης των συλλεκτών με πολύχρωμη απορροφητική επιφάνεια σε σχέση με αυτή των μαύρων συλλέκτων και σε σχέση με το πλεονέκτημα της αισθητικής ενσωμάτωσής τους στα κτίρια. / The abstract is not available.
345

Μελέτη της διάχυσης αιωρημάτων των πρωτεϊνών του φακού με δυναμική σκέδαση φωτός: συσχετισμός με το φαινόμενο του καταρράκτη

Γιαννοπούλου, Αθηνά 15 February 2008 (has links)
Στη διδακτορική αυτή διατριβή πραγματοποιείται η μελέτη των δυναμικών ιδιοτήτων των πρωτεϊνών του βοδινού φακού με τη μέθοδο της Δυναμικής Σκέδασης Φωτός και επιχειρείται ο συσχετισμός των ιδιοτήτων αυτών με το φαινόμενο του καταρράκτη. Μελετήθηκαν δυο μοντέλα καταρράκτη, ο «ψυχρός» καταρράκτης, που προκύπτει με ψύξη του φακού κάτω από τους 17 οC και ο «θερμός» καταρράκτης που προκύπτει με θέρμανση του φακού πάνω από τους 50 οC. Οι μετρήσεις στις διάφορες θερμοκρασίες πραγματοποιήθηκαν σε όλο το φάσμα συγκεντρώσεων, από πολύ αραιά μέχρι πολύ πυκνά αιωρήματα των πρωτεϊνών του φακού. Επιπλέον, μελετήθηκαν τρία ξεχωριστά συστήματα: ομογενή αιωρήματα α) από ολόκληρους φακούς νεαρών βοδιών, β) από τους πυρήνες των φακών νεαρών βοδιών και γ) α-κρυσταλλινών, οι οποίες αποτελούν το είδος των πρωτεϊνών με το μεγαλύτερο ποσοστό στο φακό (45 %) και επιπλέον έχουν το μεγαλύτερο μοριακό βάρος (800 kDa). Για τη μελέτη των α-κρυσταλλινών, προηγήθηκε απομόνωση και διαχωρισμός των διάφορων ειδών πρωτεϊνών του φακού με χρωματογραφία πηκτής. Από την ανάλυση των αποτελεσμάτων προέκυψε ότι: Τα αιωρήματα των πρωτεϊνών του φακού περιγράφονται από τέσσερις μηχανισμούς διάχυσης: τη συλλογική διάχυση, η οποία εμφανίζεται σε ενδιάμεσες συγκεντρώσεις (c>75 mg/ml) και γίνεται βαθμιαία πιο γρήγορη όταν αυξάνει η συγκέντρωση και την αυτοδιάχυση των α-κρυσταλλινών, των HMα-κρυσταλλινών και των συσσωματωμάτων των κρυσταλλινών (c>200 mg/ml), η οποία γίνεται βαθμιαία πιο αργή με αύξηση της συγκέντρωσης. Όλοι οι μηχανισμοί διάχυσης γίνονται βαθμιαία πιο αργοί κατά την ψύξη των αιωρημάτων. Το ίδιο ισχύει και κατά τη θέρμανση σε μια σταθερή θερμοκρασία (Τ>50 οC) με την αύξηση του χρόνου θέρμανσης. Όσο αυξάνεται η συγκέντρωση σε μια δεδομένη υψηλή θερμοκρασία (Τ>50 οC) αυξάνεται και ο αριθμός ή/και το μοριακό βάρος των συσσωματωμάτων των κρυσταλλινών. Όσο αφορά τον ψυχρό καταρράκτη, η σκεδαζόμενη ένταση αυξάνεται απότομα, ενώ εμφανίζονται «περιοχές» υψηλής συγκέντρωσης για T<TC, όπου TC η κρίσιμη θερμοκρασία σχηματισμού του ψυχρού καταρράκτη. Τα συμπεράσματα που προέκυψαν από τη διδακτορική αυτή διατριβή είναι σημαντικά για την κατανόηση των βασικών μηχανισμών των αλληλεπιδράσεων των πρωτεϊνών του φακού τόσο σε φυσιολογικές όσο και σε παθολογικές συνθήκες, καθώς επίσης για την έγκαιρη διάγνωση των πρώιμων σταδίων του γεροντικού καταρράκτη. / Protein condensation is the molecular basis for many neurodegenerative diseases such as Alzheimer’s disease and lens cataract. The cause of protein condensation (aggregation and/or phase separation) and the route to the condensed state are still a matter of debate, despite the intense research efforts on the subject. The present dissertation aims at studying the molecular basis of lens cataract in mammal lenses. The fact that the lens is a complex, dense dispersion of proteins (called crystallines) in water is an important obstacle that makes the understanding of the cataract onset in the lens a tough problem if not an impossible task. A strategy to overcome this obstacle is to study the cataract onset in simpler systems, e.g. dispersions of the various crystalline species at various protein concentrations ranging from very dilute dispersions to dense ones such as the intact lens. In this work we investigate the dynamics of bovine lens proteins dispersions by means of Dynamic Light Scattering, in an effort to reveal possible correlations of their behavior with the cataract effect. Two models of cataract were studied; the “cold” cataract, that is caused by cooling lens proteins below 17 οC and the “heat-induced” cataract, caused by heating lens proteins above ~45-50 οC. The temperature dependence of the diffusion coefficient was studied over a wide range of concentrations, from the very dilute limit up to the dense regime approaching lens concentration. The studies were carried out for three different young bovine lens protein dispersions. (a) Lens homogenates consist of the total lens content, (b) homogenate dispersions of the nucleus content, and (c) dispersions of isolated α-crystallins, i.e. the species that dominate in DLS among lens proteins. α-crystallins were separated from the mixture of lens proteins by using gel-filtration chromatography. The main conclusions of the present work are the following. The dynamics of lens protein dispersions are described by four diffusion mechanisms: one collective diffusion process that appears at moderate concentrations, c>75 mg/ml, and becomes faster with increasing concentration and three self-diffusion processes of α-crystallins, HMα-crystallins and large aggregates of crystallins (c>200 mg/ml). Self-diffusion becomes slower with increasing concentration. All diffusion mechanisms become slower by lowering the temperature of the dispersions. The same holds when the dispersions are heated at a constant temperature above 50 οC by increasing the heating time. Concerning “cold” cataract, it was observed that the scattered intensity grows rapidly, while “domains” of very high concentration appear for T<TC, where TC denotes the critical temperature for “cold” cataract formation.
346

Akies lęšiuko ultragarsinių, biocheminių ir mechaninių savybių įvertinimas / Evaluation of ultrasonic, biochemical and mechanical properties of eye lens

Raitelaitienė, Ramunė 13 January 2006 (has links)
Aging lens undergoes the changes in the amount of water soluble lens proteins and their redistribution from low molecular weight to high. This results in the development of high molecular weight aggregates, which change the lens transparency, increase light scattering and contribute to the hardening of the lens. All these disturbances cause changes in ultrasound attenuation. Hardness of the cataractous lens is one of the major factors influencing the suitability of a patient for fhacoemulsification. Age and nuclear color have been shown to be good clinical markers of lens hardness, but there is a need of more quantitative and objective examination method. In this work a new methodics of assessement of eye lens hardness in vitro was developed, the hardness of dogs and human eye lenses was assessed experimentally, the investigation of ultrasound attenuation coefficient, the amount of water soluble lens proteins and their distribution to the fractions of different molecular weight was performed. A strong correlation between lens hardness and ultrasound attenuation was investigated. The results enable to evaluate lens hardness pre-operatively and non invasively and help surgeons when choosing patients to the phacoemulsification method of cataract extraction. The performed investigation confirmed that the opacification of the lens is due to the changes in the amount of water soluble lens proteins and the presence of high molecular weight compounds, which disturb the light... [to full text]
347

Optical biopsy systems using ultra-slim objectives for the diagnosis of breast cancer

Kyrish, Matthew 16 September 2013 (has links)
One in eight women in America will develop breast cancer at some point in their lives. Breast cancer is the second deadliest form of cancer for women in the United States. When a suspicious region of the breast is detected, the tissue is diagnosed by removing a sample, preparing an H&E section, and performing histopathology. This procedure is expensive, invasive, and can take days to return a diagnosis. An alternative to excision biopsies is to instead perform an optical biopsy. This work details endomicroscopes intended to perform optical biopsies in breast tissue. The work address two issues limiting current optical biopsy systems: insufficient resolution and inability to reject out of focus light. To improve the resolution of current endomicroscopes, ultra-slim objectives are developed using optical plastics and zero alignment fabrication techniques. These objectives can outperform current alternative endomicroscope objectives in terms of performance across the field of view and chromatic aberration correction, while remaining as narrow as a biopsy needle. Next, an endomicroscope which utilizes structured illumination to perform optical section is designed, tested, and evaluated on ex vivo breast biopsies. The new endomicroscope provides high contrast images by reducing out of focus background light. Finally, an achromatic, ultra-slim objective and the structured illumination endomicroscope are integrated to form an optical biopsy system with improved lateral resolution and axial response. This integrated system is a step forward for in vivo microscopy and cancer diagnoses.
348

Dirbtinių ašarų poreikis nešiojant hidrogelinius ir silikono hidrogelinius kontaktinius lęšius / The Demand of Artificial Tears Using Hydrogel and Silicone Hydrogel Contact Lenses

Jakšienė, Neringa 26 June 2013 (has links)
Trečdalis gyventojų kenčia dėl pavargusių ir sausų akių sindromo (Pečeliūnienė, 2006). Juos vargina jausmas, lyg į akis būtų pripilta smėlio ar žvyro, akis gali parausti arba atsiranda būdingas svetimkūnio bei diegimo, raižymo pojūtis, šviesos baimė. Rytais, tik atsimerkus, gali būti jaučiamas neilgalaikis aštrus skausmas ar padidėjęs ašarojimas bei akių nuovargis, matymo pablogėjimas, kontaktinių lęšių netoleravimas. Pusė patiriančiųjų pavargusių akių simptomus jų visai negydo. Nesiėmus reikiamų priemonių, tokiems žmonėms vėliau diagnozuojamas sausų akių sindromas (SAS). Ypač dažnai sausumas vargina pacientus, dėvinčius kontaktinius lęšius – ašarų turi pakakti dar ir lęšiui sudrėkinti. / One third of people suffer from tired and dry eye syndrome (Pečeliūnienė, 2006). They weary a feeling of eye full of sand or gravel, ache and cutting, fair of light, an eye can get red. In the mornings when eyes are just opened, there can be a short period of sharp ache or increased tearing and also eye tiredness, vision deterioration, intolerance of contact lenses. A half of people who suffer from eye tiredness, do not treat them at all. When taking no measures, a dry eye syndrome is later diagnosed (SAS). This very often appear to people with contact lenses - tear drops must be also enough for irrigating the lenses.
349

Frost Heave: New Ice Lens Initiation Condition and Hydraulic Conductivity Prediction

Azmatch, Tezera Firew Unknown Date
No description available.
350

PERFORMANCE OF PAN-TILT TRACKER BASED ON THE PIN-HOLE LENS MODEL

Mehta, Vikas Chandra 01 January 2009 (has links)
In the modern day, recognition and tracking of face or the iris is potentially one of the most powerful ways of differentiating between an authentic person and an imposter. Our method uses stereo vision to track the 3-Dimensional coordinates of a target equivalent to a person’s eyes and using a pan-tilt unit we target these areas for additional processing such as iris or facial imaging. One of the most important parts involved in tracking is the way the pan-tilt unit is calibrated. There have been techniques in the past where PTZ (Pan-tilt-zoom) digital camera has been used and calibrated using self calibration techniques involving a checker board calibration grid but the tracking error was found to be large in these techniques. We introduce a more accurate form of calibration of the pantilt unit using photogrammetric calibration technique and view the pan-tilt unit as an emulation of a Pinhole Lens Model to detect and track the target. The system is demonstrated on ideal targets.

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