Field Weakening Control of Interior Permanent Magnet Synchronous Motor Employing Model Order Reduction

Various control strategies have been adopted for the field weakening control of the interior permanent magnet synchronous motors. Most of these either use the magnetic model parameters or utilize the approaches like the look up tables to minimize the effects of parametric sensitivity. The variation of the inductance values due to the magnetic saturation or the cross-coupling and fluctuation in the stator resistance and the permanent magnet flux due to the temperature difference can significantly affect the control performance especially at high speeds. In this thesis, the field weakening algorithm has been proposed that employs one of the model order reduction technique, i.e. orthogonal interpolation method. This technique obtained from reducing the order of the finite element model of the machine takes the stator current components as input and outputs the corresponding flux linkage components. At first, the control design was implemented utilizing the reduction technique that contained the motor parameters to test the validity of the orthogonal interpolation method in the field weakening operation. Thereupon, the technique was designed operating independent of any machine parameter that put into place the orthogonal interpolation method and its inversion for the references calculation. The simulink feature, ‘algebraic constraint’, was used in combination with the reduction technique to produce the required current components. The control techniques were implemented in the field oriented control scheme. The methods were at first tested through simulations in the MATLAB/Simulink environment and then the experiments were performed in the dSPACE laboratory for validity of the results. The results provided in the end confirm the feasibility of the approach used. The motor operates well in the field aweakening region and can operate in the wide speed range. The results also confirm that the approach operating independent of the machine parameters exhibit better control performance

DESIGN OF A NOVEL THERMO-ELECTRIC COOLING DEVICE CAPABLE OF ACHIEVING CRYOGENIC TEMPERATURES FOR DENTAL PULP TESTING

Dental pulp testing is a diagnostic test in endodontics to test whether the dental pulp is dead or alive. Thermal tests (cold and hot) and electrical pulp testing techniques are two of the most common pulp sensibility tests currently being used. Although cold tests have shown more promising results in comparison to other techniques, the current methods used for cold testing have safety concerns as they involve direct application of the cold agent to the tooth. This study proposed a thermoelectric cooling based dental pulp testing device capable of achieving cryogenic temperatures and varying this temperature below 0℃ up to -60℃. This device is safe in operation and provides availability for on-site application due to its portability and stand-alone features. Thermoelectric cooling is based on the Peltier effect, which allows a temperature difference across a thermoelectric module and results in one side of the module becoming cold while the other side becomes hot. The challenge for such devices based on the Peltier effect is that the heat on the hot side of the module needs to be dissipated so that it is not too hot to burn the patient’s skin. This study explored the application of the phase change cooling technique in the form of heat pipes and vapor chambers to address this challenge. Finally, a thermoelectric cooling system capable of achieving -60℃ at the probe for pulp sensibility testing was proposed through modeling and simulation in Comsol Multiphysics software and experimentally validated using off-the-shelf hardware

Celebrity Endorsement: A Congruity Measure of Personalities

Purpose In marketing communications strategy, the use of celebrity is a common practice for major firms in supporting the brand imagery. Based on the cognitive theories of endorsement efficiency, the congruence between the personality of a brand being endorsed and that of the targeted personality of a celebrity is tested. Design/methodology/approach A total of 120 survey respondents brand-personality perceptions and perceptions of celebrity personality were measured and analysed. The congruence measures were used as indicators from the adjectives of Aaker's Scale to analyse the congruity effect. Findings The results indicated that a successful brand promotion needs congruency between the brand's and the endorser's personality, though it may be moderate. Originality/value The research undertaken on celebrity endorsement in this paper will be useful on both academic and professional platform, as this study derives specific insights to practitioners and it provides a basis for guiding further research beyond the mere celebrity selection decision. It enhances the usefulness of the congruency effect, providing a knowledge base for determining an overall brand positioning strategy. Also, it looks into the perception of Indian consumers on celebrity endorsement, providing theory for scholarly and directives for managers and professionals. Keywords: Celebrity Endorsement, Brand Personality, Congruenc

Importance of Brand Personality To Customer Loyalty: A Conceptual Study

Customer loyalty is viewed as the strengths of the relationship between an individual’s relative attitude and repeat patronage. Here an attempt has been made to probe into the behaviour of a customers’ willingness to buy a brand/product, of what are the related factors which influences his buying behaviour and attitude towards the brand. An investigation is done to highlight a point of what are the influencing factors which compels him to be a loyal for a brand. The theoretical study and the conceptual model, here, envisages the concept of brand loyalty by passing through the concept of brand personality. The study findings suggest a conceptual model that combines the theories of brand personality with the necessary dispositional variables to explain the customer’s loyalty processes. This model also rises to the marketing challenge of building long-term consumer relationships. Customer‘s loyalty, therefore, might be strengthened or retained by keeping in consideration various other factors through communicating a good brand relationship by involving the concept of brand personality, thus, enhancing the customer relationship building with social and resource exchanges and thus positively affecting the satisfaction of the customer. The theoretical framework will help the researches to further investigate into the concept of brand personality enhancing the customer loyalty. Keywords: Brand Personality, Customer Loyalty, Conceptual Mode

Conceptual framework on teaching capacitors and inductors

The objective of this work is to suggest a conceptual framework on teaching capacitors and inductors in order to improve teaching abilities and to eliminate some fundamental misconceptions. The effort initially deals with resolution of physical structure and structural concepts/parameters of the devices and then resolves DC and AC responses of the inductors and capacitors. The resolutions are achieved by considering basic serious RL and RC circuits and resolving the circuits both theoretically and experimentally. As a result, an alternative teaching approach is offered and also a novel instructional material is developed and suggested. Some teaching clues are briefly inserted to guide teachers/instructors to reach a higher comprehension level. It is believed that the implications of the developed teaching material would be quite high and beneficial

Frequency of Abnormal Menstrual Cycles Associated with Raised BMI

Objective: The main aim of this study was to find the frequency of menstrual cycle abnormalities which were associated with higher BMI.Study Design: It is a cross sectional type of study.Place and Duration of study: This study was carried out in a duration of 9 months from August 2018 to April 2019 in Gynecology and Obstetrics department of Services hospital Lahore.Materials and Methods: A total of 100 cases which were in fertile group i.e. Age greater than 12 years were included in this study. Inclusion criteria was to have menstrual abnormalities for at least last 3 cycles. Exclusion criteria included patients with bleeding tendencies, abnormalities of uterus and hormonal abnormalities. Body mass index of every patient was calculated and the patients who had BMI greater than 25kg/m2 were labeled as high. Informed consent was taken from all the patients or their relatives. A pre-designed proforma was used to collect the data. Ethical committee approval was taken.Results: There were 100 patients selected for the study. Mean age in our study was 20.21±4.57 years. The mean time period for there were menstrual abnormalities was 7.21±2.34 months. 32% of the patients had raised BMI. 64% were taking treatment for this. The patients who had age of menarche greater than 14 years, incidence of increased BMI was much higher seen in 16 (47. 06%) of cases. Patients who had previous treatment for delayed menstruation also had increased BMI which was seen in 23 (40. 35%) cases.Conclusion: There is high association of menstrual abnormalities with Raised BMI and other factors like delayed menarche and prior treatment for it increases the incidence significantly

Kızıl Şahin (Buteo rufinus)'de yeni bir bit türü: Aegypoecus guralpi sp. n. (Phthiraptera: Ischnocera)]

A total of ten louse samples were collected from a long-legged buzzard (Buteo rufinus) in Hatay province in Mediterranean Region of Turkey. All of the louse samples were identified as a new species morphologically and named as Aegypoecus guralpi

Bir Bilgi Tanımının Eleştirisi: Devvânî’nin Risâle fî Ta‘rîfi’l-‘İlm Bağlamında

Bu çalışmada, Celâleddîn ed-Devvânî’nin (öl. 908/1502) Risâle fî ta‘rîfi’l-‘ilm isimli risalesi tahlil edilmektedir. Risalede müteahhir dönem kimi kelamcıların benimsediği bir bilgi tanımı eleştirilmektedir. Araştırması yapılan bilgi tanımının üç bileşeni bulunmaktadır: Sıfat, temyiz ve çelişiğe ihtimali olmamak. Bilgi kategori olarak bir sıfattır. Bu sıfat ile temyiz elde edilir. Sonuç bilgidir ve bu bilginin çelişiğine ihtimali olmamalıdır. Devvânî bu bilgi tanımının sekiz ihtimalini incelemektedir. Sekiz ihtimalin her birinde farklı sorunlar ortaya çıkmaktadır. Devvânî’ye göre sözü edilen tanım, her ihtimale göre sorunludur. Fakat Devvânî eleştirdiği bilgi tanımının yerine başka bir bilgi tanımı önermemektedir. Makalede öncelikle kelam düşünce tarihinde sözü edilen bilgi tanımına ulaşma süreci anlatılacaktır. İlk dönemden itibaren yapılan bilgi tanımları özetlenecektir. Tanımların güçlü ve zayıf yönleri yorumlanacaktır. İslam düşüncesinde bilginin mahiyetine yönelik iki ana akım vardır: Fahreddin er-Râzî’nin (öl. 606/1210) başını çektiği ilk akıma göre mutlak bilgi bedihidir, tanımlanamaz. İkinci akıma göre mutlak bilginin mahiyeti nazarîdir, tanımlanabilir. Makaledeki ilk başlık İslam düşüncesinde bilgi tanımları ve eleştirileridir. Çalışmadaki ikinci başlık özgünlük iddiası taşımaktadır. Çünkü Devvânî’nin anılan risalesi ilk kez değerlendirilecektir. Risalenin sonucuna göre bilginin özünü bulmak için yapılan tanım, her açıdan temelsizdir. İslam düşünce tarihinde özcülük karşıtlığının bir yansıması olarak risalenin değerlendirilmesi önem arz etmektedir. Modern çalışmaların çoğu bu risaleyi Devvânî’nin eserleri arasında saymamaktadırlar. Hayreddin ez-Ziriklî (öl. 1976) tarafından kaleme alınan el-Aʿlâm adlı biyografi kitabında Risâle fî ta‘rîfi’l-‘ilm Devvânî’nin eserleri arasında sayılmıştır. Birden çok yazma nüshanın girişinde de eser, Devvânî’ye açıkça nispet edilmiştir. Çift taraflı yapılan araştırmalar sonucunda eserin müellife aidiyeti sağlanmıştır. Ancak aynı risaleyi içeren başka iki yazma nüshada eser, Şâirzâde isimli meçhul bir şahsa ait gibi gösterilmektedir. Fakat bu isimle ilgili herhangi bir bilgiye ulaşılmamıştır. Bu isim bir müellif olmaktan çok müstensih ismine benzemektedir. İki ismin birbirine karıştırılması sonucunda böyle bir yanlışlık olmuş gibi gözükmektedir. Devvânî’nin küçük hacimli bu risalesi dönemin ilmi atmosferine ve entelektüel seviyesine ışık tutacak niteliktedir. Adudüddîn Îcî’nin (öl. 756/1355) Mevâkıf adlı klasik kelam kitabında sözü edilen bilgi tanımı diğer bilgi tanımlarından üstün tutulmaktadır. Kusursuz olarak takdim edilen bu bilgi tanımı yerine Cürcânî (öl. 816/1413) Şerh-i Mevâkıf’ta Mâtürîdî’ye (öl. 333/944) atfedilen bilgi tanımını tercih etmiştir. Bu tercih, Devvânî’nin de içinde bulunduğu gelecek kuşaklar için örtük bir eleştiri kabul edilmiştir. Cürcânî’nin gelişigüzel tercih de bulunmadığı yorumunu yapanlar, tanımın üzerine giderek eleştirileri devam ettirmiştir. Risalede ortaya konulan ince işçilik, eleştirel düşüncenin yoğun bir şekilde işletildiğini gözler önüne sermektedir. Risalenin doğru anlaşılması mantık ilminin bilinmesine ve takip edilmesi ise yoğun bir dikkate bağlıdır. Mantık ilminin tasavvur, tasdik, hüküm, nakz gibi kavramlarından alınan yardımla bilginin tanımı çeşitli açılar incelenmektedir. Mantık ilminde kesin, zan, taklit, şüphe gibi bilginin her türlü katmanı tek tek araştırılmaktadır. Kelam ilminde ise bilginin ideal düzeyi olan kesin olmasına dikkat edilmektedir. Kesin olmayan bir bilinen, kelam ilminde bilgi sayılmamaktadır. Çünkü kelamcıların temel hedefi, dinî inançları kesin bilgi üzerine inşa etmektir. Kesin olmayan, muhtemel bilginin başka bir şeye temel olması yanlıştır. Bilinenler arasındaki bir bilginin kesinlik düzeyine ulaşması için doğru olması ve diğer ihtimalleri dışarıda bırakması gerekmektedir. Devvânî’nin risalesinde incelediği bilgi tanımındaki kesinlik için koşulan diğer şart aksinin yanlış olmasıdır. Bir bilginin kesin doğru sayılması tersinin yanlış olmasına bağlıdır. İşte bu risalede ihtimal dışı bırakılmak istenen çelişiklerin veya çelişkinin nerede aranacağı tartışılmaktadır. Bilgi, insan zihninden, dış dünyadan veya ikisi arasındaki ilişkinin kendisinden ayrılmamaktadır. Öyleyse çelişki bu üç alanda aranmalıdır. Risalede Devvânî bilgi tanımını bu üç alanı dikkate alarak eleştirmektedir