DFM(A)- aspects for a horn antenna design

In this paper aspects of design for manufacturability and assembly (DFMA) are applied to the design of coaxially fed standard gain horn antenna for 1.70 - 2.60 GHz. Possibilities to utilize cross-technological approach method is examined. Methods of DFMA for laser processing are covered and practical design guides and methods are developed. Antenna construction for easy manufacturing and specialized performance is shown. Required dimensions and tolerances are discussed and suitable materials for laser processing are selected.

Antenna Design for Contactless IC Card Applications

Contactless integrated circuit cards are one form of application of radio frequency identification. They are used in applications such as access control, identification, and payment in public transport. The contactless IC cards are passive which means that both the data and the energy are transferred to the card without contact using inductive coupling. Antenna design and optimization of the design for contactless IC cards defined by ISO/IEC14443 is studied. The basic operation principles of contactless system are presented and the structure of contactless IC card is illustrated. The structure was divided between the contactless chip and the antenna. The operation of the antenna was covered in depth and the parameters affecting to the performance of the antenna were presented. Also the different antenna technologies and connection technologies were provided. The antenna design process with the parameters and the design tools isillustrated and optimization of the design is studied. To make the design process more ideal a target of development was discovered, which was the implementation of test application. The optimization of the antenna design was presented based on the optimization criteria defined in this study. The solution for the implementation of these criteria and the effect of each criterion was found. For enhancing the performance of the antenna a focus for future study was proposed.

Finnish buyers’ perceptions of Indian textile and clothing suppliers: Country of origin in focus

Choosing the right supplier is crucial for long-term business prospects and profitability. Thus organizational buyers are naturally very interested in how they can select the right supplier for their needs. Likewise, suppliers are interested in knowing how their customers make purchasing decisions in order to effectively sell and market to them. From the point of view of the textile and clothing (T&C) industry, regulatory changes and increasing low-cost and globalization pressures have led to the rise of low-cost production locations India and China as the world’s largest T&C producers. This thesis will examine T&C trade between Finland and India specifically in the context of non-industrial T&C products. Its main research problem asks: what perceptions do Finnish T&C industry buyers hold of India and Indian suppliers? B2B buyers use various supplier selection models and criteria in making their purchase decisions. A significant amount of research has been done into supplier selection practices, and in the context of international trade, country of origin (COO) perceptions specifically have garnered much attention. This thesis uses a mixed methods approach (online questionnaire and in-depth interviews) to evaluate Finnish T&C buyers’ supplier selection criteria, COO perceptions of India and experiences of Indian suppliers. It was found that the most important supplier selection criteria used by Finnish T&C buyers are quality, reliability and cost. COO perceptions were not found to be influential in purchasing process. Indian T&C suppliers’ strengths were found to be low cost, flexibility and a history of traditional T&C expertise. Their weaknesses include product quality and unreliable delivery times. Overall, the main challenges that need to be overcome by Indian T&C companies are logistical difficulties and the cost vs. quality trade-off. Despite positive perceptions of India for cost, the overall value offered by Indian T&C products was perceived to be low due to poor quality. Unreliable delivery time experiences also affected buyer’s reliability perceptions of Indian suppliers. The main limiting factors of this thesis relate to the small sample size used in the research. This limits the generalizability of results and the ability to evaluate the reliability and validity of some of the research instruments.

Antenna feed design for omnidirectional broadband antenna

This thesis is about development broadband feed for two-mirror antenna system that match following requirements: beamwidth from 45 to 90 degrees at -3 dB level, circular polarization, absence of radiation to the lower hemisphere area. Literature review was done in the areas of the UWB antennas creation. During the work attempts were made to create a feed in a form of the quad ridged horn and "eleven" antennas. The latter is introduced as the most effective feed among all antennas discussed in thesis. Radiation patterns and other results for "eleven" antenna were obtained. Results were saved as far field sources and placed slightly below focal point into the two-mirror antenna system, because phase center of the “eleven” antenna is predominantly shifted upwards. Directivity patterns for the two-mirror system were obtained and the conclusions about the work results have been made

Incorporating Sustainability in Global Sourcing Process, Industry Focus- Apparel / Textile

This is a Master’s thesis research, which mainly aims at identifying the sustainability issues in sourcing process and to identify the core competencies in sourcing process through triple bottom line adaptation. The focus of this thesis is on apparel industry’s sourcing process. The purpose of this thesis is to examine global apparel industry’s reality in their sourcing process and how buyers-suppliers are cooperating with their sourcing process to incorporate sustainability. Other goal of this research paper is to provide recommendation for sustainable sourcing process for companies and how the stakeholders can be benefitted by sustainable sourcing. The literature review part of this paper has presented the research gaps from the earlier researches along with the key concepts, academic purposes and key definitions. Theoretical framework chapter has focused on global sourcing strategies and firm’s competencies and sustainable strategies. From the theoretical framework, author has presented essential theory which establishes the link between research questions and proposed hypotheses. Main results and findings have been presented in empirical findings and in data analysis chapter. This study is an exploratory research followed by deductive method and primary data has been used to evaluate the current situation of apparel industry; which will assist to build the recommendation model. Primary data has been collected through online questionnaires and secondary data has used to cover the literature and theoretical parts. Therefore, the potential outcome of this paper will display the importance of sustainable sourcing from academic point of view and also from the business perspective. As a final point, this paper has followed the research objectives and has generated some new directions for further studies.

Perceptions of green branding and identity building amongst small Finnish textile producers

The textile industry is one of the most polluting industries in the world. The amount of air and water pollution it causes puts a burden on the environment. There are companies who have taken the environmental and social aspects into account in the their production and chosen to operate in a green manner. This thesis studies how the phenomenon of green branding is seen from the perspectives of small Finnish textile companies. The theory used in this thesis has to do with green branding and identity building. The theory is used to analyze the results of the empirical findings. The main research question that the thesis aims to answer is how green branding is perceived within the Finnish textile industry. In order to answer the main research question, empirical data was collected from five relevant companies within the Finnish textile industry. The companies interviewed for the study were WST, Saana ja Olli, RCM, R-collection and Tiensivu. The study was conducted as a multiple case based study where multiple experts from green companies were interviewed. The experts were all owners or employees of companies that have a so-called green brand identity. The data was collected through semi-structured interviews, where the relevant experts from each company were interviewed either by themselves, in pairs or in groups. The data that was collected for this study was primary data, and the results of the study are mainly based on the experiences and opinions of the experts interviewed. The data collected does not cover the entire green textile industry within Finland, but study does however give a fairly comprehensive view of the phenomenon, as the textile industry in Finland is quite concise. The general findings of the study show that all experts from the companies interviewed agreed that a green brand identity does benefit their company in one way or the other. The findings also show contradictions with the older theory (eg. Charter et al. 1999, Pickett et al. 1995), and perhaps give a more modern view of the thoughts within the industry.

Photodamage to Oxygen Evolving Complex - An Initial Event in Photoinhibition of Photosystem II.

Photosystem II (PSII) of oxygenic photosynthesis is susceptible to photoinhibition. Photoinhibition is defined as light induced damage resulting in turnover of the D1 protein subunit of the reaction center of PSII. Both visible and ultraviolet (UV) light cause photoinhibition. Photoinhibition induced by UV light damages the oxygen evolving complex (OEC) via absorption of UV photons by the Mn ion(s) of OEC. Under visible light, most of the earlier hypotheses assume that photoinhibition occurs when the rate of photon absorption by PSII antenna exceeds the use of the absorbed energy in photosynthesis. However, photoinhibition occurs at all light intensities with the same efficiency per photon. The aim of my thesis work was to build a model of photoinhibition that fits the experimental features of photoinhibition. I studied the role of electron transfer reactions of PSII in photoinhibition and found that changing the electron transfer rate had only minor influence on photoinhibition if light intensity was kept constant. Furthermore, quenching of antenna excitations protected less efficiently than it would protect if antenna chlorophylls were the only photoreceptors of photoinhibition. To identify photoreceptors of photoinhibition, I measured the action spectrum of photoinhibition. The action spectrum showed resemblance to the absorption spectra of Mn model compounds suggesting that the Mn cluster of OEC acts as a photoreceptor of photoinhibition under visible light, too. The role of Mn in photoinhibition was further supported by experiments showing that during photoinhibition OEC is damaged before electron transfer activity at the acceptor side of PSII is lost. Mn enzymes were found to be photosensitive under visible and UV light indicating that Mn-containing compounds, including OEC, are capable of functioning as photosensitizers both in visible and UV light. The experimental results above led to the Mn hypothesis of the mechanism of continuous-light-induced photoinhibition. According to the Mn hypothesis, excitation of Mn of OEC results in inhibition of electron donation from OEC to the oxidized primary donor P680+ both under UV and visible light. P680 is oxidized by photons absorbed by chlorophyll, and if not reduced by OEC, P680+ may cause harmful oxidation of other PSII components. Photoinhibition was also induced with intense laser pulses and it was found that the photoinhibitory efficiency increased in proportion to the square of pulse intensity suggesting that laser-pulse-induced photoinhibition is a two-photon reaction. I further developed the Mn hypothesis suggesting that the initial event in photoinhibition under both continuous and pulsed light is the same: Mn excitation that leads to the inhibition of electron donation from OEC to P680+. Under laser-pulse-illumination, another Mn-mediated inhibitory photoreaction occurs within the duration of the same pulse, whereas under continuous light, secondary damage is chlorophyll mediated. A mathematical model based on the Mn hypothesis was found to explain photoinhibition under continuous light, under flash illumination and under the combination of these two.

Oppimisen haasteet sukupuolinäkökulmasta : esimerkkinä tekstiili- ja vaatetusteollisuus

Summary: Gender and learning - examples from the textile and clothing industry

Purification and fractionation by nanotiltration in dairy and sugar and sweetener industry applications

Nanotiltration is a membrane separation method known for its special characteristic of rejecting multivalent ions and passing monovalent ions. Thus, it is commonly applied with dilute aqueous solutions in partial salt removal, like in drinking water production. The possibilities of nanofiltration have been studied and the technique applied in a wide branch of industries, e.g. the pulp and paper, the textile and the chemical processing industry. However, most present applications and most of the potential applications studied involve dilute solutions, the permeating stream being generally water containing monovalent salts. In this study nanotiltration is investigated more as a fractionation method. A well-known application in the dairy industry is concentration and partial salt removal from whey. Concentration and partial demineralization is beneficial for futher processing of whey as whey concentrates are used e.g. in baby foods. In the experiments of this study nanotiltration effectively reduced the monovalent salts in the whey concentrate. The main concern in this application is lactose leakage into the permeate. With the nanofiltration membranes used the lactose retentions were practically ? 99%. Another dairy application studied was the purification and reuse of cleaning solutions. This is an environmentally driven application. An 80% COD reduction by nanofiltration was observed for alkaline cleaning-in-place solution. Nanofiltration is not as commonly applied in the sugar and sweeteners industry as in the dairy industry. In this study one potential application was investigated, namely xylose purification from hemicellulose hydrolyzate. Xylose is raw material for xylitol production. Xylose separation from glucose was initially studied with xylose-glucose model solutions. The ability of nanofiltration to partially separate xylose into the permeate from rather concentrated xylose-glucose solutions (10 w-% and 30 w-%) became evident. The difference in size between xylose and glucose molecules according to any size measure is small, e.g. the Stokes diameter of glucose is 0.73 nm compared to 0.65 nm for xylose. In further experiments, xylose was purified into nanoliltration permeate from a hemicellulose hydrolyzate solution. The xylose content in the total solids was increased by 1.4—1.7 fold depending on temperature, pressure and feed composition.

Vaatetus- ja tekstiilimateriaalien ekologinen elinjakson hallinta Talousvarikon toiminnoissa

Tämän case -tutkimuksen tarkoituksena on kartoittaa tekstiili- ja vaatetusmateriaalien ekologista elinjakson hallintaa Talousvarikon toiminnoissa ja tutkimalla mahdollisuuksia soveltaa saatuja tuloksia. Talousvarikko on Puolustusvoimien Materiaalilaitoksen alainen järjestelmävastuuvarikko, jonka tehtävänä on varusmiesten ja kadettien vaatetuksen hankinta- ja ylläpitotoiminnot. Talousvarikko jakautuu neljälle paikkakunnalle. Hämeenlinnassa on hankinta-, hallinto- ja materiaaliosasto. Säkylässä, Mikkelissä ja Sodankylässä ovat vaatetuskorjaamot. Tekstiilimateriaalien elinkaariajattelussa tarkastellaan raaka-aineiden jaottelua ja maailman kuitutuotantoa. Tekstiilikuidut jaotellaan luonnon- ja tekokuituihin. Luonnonkuidut ovat pääosin luonnon raaka-aineita ja tekokuidut ovat synteettisesti valmistettuja. Tekstiilikuitujen- ja materiaalien vaikutus ekologiseen elinjakson hallinnan vaiheisiin on riippuvainen raaka-aineidenalkuperästä. Vaatetus- ja tekstiilimateriaalin elinkaari muodostuu tuotekehityksestä, hankinnasta, valmistuksesta, käytöstä, huollosta ja hylkäyksestä. Ekologista elinjakson hallintaa tarkastellaan materiaalivirta- ja elinkaarianalyysien kautta. Elinkaarianalyysin tarkastelu painottuu vaikutusluokkien arvottamiseen ja materiaalivirta-analyysissä tarkastellaan ainevirtoja ja sitä kautta jätteiden määrän vähentämistä. Joutsenmerkin valintakriteerien pohjana on aina tuotteiden elinkaarianalyysi. Joutsenmerkin valintakriteerien soveltaminen Talousvarikon toimintoihin vaatetus- ja tekstiilimateriaalin elinkaaren jokaisessa vaiheessa antaa mahdollisuuden lisätä ekologista elinkaaren hallintaa Talousvarikon toiminnoissa. Ympäristönäkökohtien huomioiminen tuotekehityksessä ja hankinnoissa antaa mahdollisuuden tehdä tilauksia / sopimuksia yhteiskuntavastuullisilta yrityksiltä huomioiden valmistuksen yhdeksi osaksi hankinta ja logistiikka pääprosessia.

Performance Evaluation of Six-Sectored Configuration in Hexagonal WCDMA (UMTS) Cellular Network Layout

The objective of this master's thesis is to evaluate the optimum performance of sixsectored hexagonal layout of WCDMA (UMTS) network and analyze the performance at the optimum point. The maximum coverage and the maximum capacity are the main concern of service providers and it is always a challenging task for them to achieve economically. Because the optimum configuration of a network corresponds to a configuration which minimizes the number of sites required to provide a target service probability in the planning area which in turn reduces the deployment cost. The optimum performance means the maximum cell area and themaximum cell capacity the network can provide at the maximum antenna height satisfying the target service probability. Hexagon layout has been proven as the best layout for the cell deployment. In this thesis work, two different configurations using six-sectored sites have been considered for the performance comparison. In first configuration, each antenna is directed towards each corner of hexagon, whereas in second configurationeach antenna is directed towards each side of hexagon. The net difference in the configurations is the 30 degree rotation of antenna direction. The only indoor users in a flat and smooth semi-urban environment area have been considered for the simulation purpose where the traffic distribution is 100 Erl/km2 with 12.2 kbps speech service having maximum mobile speed of 3 km/hr. The simulation results indicate that a similar performance can be achieved in both the configurations, that is, a maximum of 947 m cellrange at antenna height of 49.5 m can be achieved when the antennas are directed towards the corner of hexagon, whereas 943.3 m cell range atantenna height of 54 m can be achieved when the antennas are directed towards the side of hexagon. However, from the interference point of view the first configuration provides better results. The simulation results also show that the network is coverage limited in both the uplink and downlink direction at the optimum point.

Vaiheohjatut antenniryhmät GSM-tukiasemissa

Diplomityön aiheena oli selvittää onko Suomessa GSM-tukiasemissa käytössä vaiheohjattuja antenniryhmiäja olisiko tällaisten antennien käyttöön kiinnostusta tai mitään es-teitä. Lähtökohtana tälle työlle oli ajatus GSM-tukiasema-antennista, jota voitaisiin kääntää tarpeen mukaan haluttuun suuntaan. Vaiheohjatut antenniryhmät mahdollistavat juuri tällaisen antennin keilan kääntämisen ja muokkaamisen elektronisesti, ilman kuluvia osia. Keilan muitakin ominaisuuksia voidaan säätää, kuten muotoa ja keilojen määrää. Nämä ominaisuudet mahdollistaisivat esimerkiksi ruuhkaisilla alueilla keilojen lisäämisen, jolloin alueen puhelujen välityskapasiteetti kasvaisi.Tarvittaessa voitaisiin myös keilan muotoa muuttaa. Esimerkiksi hätätilanteessasaadaan haluttu keila suunnattua tarkasti tietylle alueelle tai toiselle tukiasemalle ja näin varmistettua kuuluvuus. Myös huoltotoimenpiteet joissakin tapauksissa helpottuisivat. Etenkin vaikeakulkuisissa paikoissa sijaitsevien tukiasemien ensiapu, esimerkiksi antennin fyysisesti kääntyessä, voitaisiin hoitaa etänä kääntämällä pelkkää keilaa ja tässä tapauksessa kääntää antenni tukiaseman normaalin huollon yhteydessä. Suurimpia ongelmakohtia kyseisen tekniikan käyttöönotossa on ollut hinta, mutta muun muassa uusien valmistustekniikoiden avulla vaiheohjattujen antenniryhmien hintoja ollaan saatu pudotettua.

Onnistuneen uuden tuotteen kehittäminen ja hallinta - Tapaustutkimus: Tekstiilialan yritys

Tuotesuunnittelu on yrityksen selviämisen kannalta erittäin tärkeä toiminto. Menestynyt tuotesuunnittelu vaatii selkeän tuotestrategian, laadukkaasti suoritetun tuotesuunnitteluprosessin ja tarvittavienresurssien yhdistämistä sekä uuden tuotteen tuottojen hallintaa myynnin seurannalla. Kohdeyrityksessä uusien tuotteiden suunnittelun ja hallinnan tärkeys on huomattu ja niiden kehittämiseksi yritys on lisäämässä panostustaan. Tämä tutkimuspyrkii tuomaan kohdeyrityksen tietoon tuotesuunnitteluun ja uuden tuotteen hallintaan vaikuttavat menestystekijät sekä tuomaan esille näitä toimintoja tukevia kehittämismahdollisuuksia. Tutkimus on normatiivinen tapaustutkimus, jossa teoria on koottu tieteellisistä, lähinnä empiirisistä tutkimuksista koostuvista artikkeleista. Yrityksen tuotesuunnitteluun liittyvät prosessit ja toiminnot on selvitetty puolistrukturoiduilla haastatteluilla sekä havainnoimalla. Tutkimuksessa havaittiin selkeitä eroja uuden tuotteen hallinnan menestystekijöiden ja yrityksen toimintojen välillä. Tuotesuunnitteluprosessin uudelleen organisointi, toimitusketjun hallinta ja tuotekohtainen kustannuslaskenta ovat asioita, joita kehittämällä yritys voi mahdollisesti parantaa uusien tuotteiden elinkaaren aikaista hallintaa ja taloudellista onnistumista sekä lisätä yrityksen kannattavuutta.

Tuning the design procedures for laser processed microwave mechanics

This research has been focused at the development of a tuned systematic design methodology, which gives the best performance in a computer aided environment and utilises a cross-technological approach, specially tested with and for laser processed microwave mechanics. A tuned design process scheme is also presented. Because of the currently large production volumes of microwave and radio frequency mechanics even slight improvements of design methodologies or manufacturing technologies would give reasonable possibilities for cost reduction. The typical number of required iteration cycles could be reduced to one fifth of normal. The research area dealing with the methodologies is divided firstly into a function-oriented, a performance-oriented or a manufacturability-oriented product design. Alternatively various approaches can be developed for a customer-oriented, a quality-oriented, a cost-oriented or an organisation-oriented design. However, the real need for improvements is between these two extremes. This means that the effective methodology for the designers should not be too limited (like in the performance-oriented design) or too general (like in the organisation-oriented design), but it should, include the context of the design environment. This is the area where the current research is focused. To test the developed tuned design methodology for laser processing (TDMLP) and the tuned optimising algorithm for laser processing (TOLP), seven different industrial product applications for microwave mechanics have been designed, CAD-modelled and manufactured by using laser in small production series. To verify that the performance of these products meets the required level and to ensure the objectiveness ofthe results extensive laboratory tests were used for all designed prototypes. As an example a Ku-band horn antenna can be laser processed from steel in 2 minutes at the same time obtaining a comparable electrical performance of classical aluminium units or the residual resistance of a laser joint in steel could be limited to 72 milliohmia.