20 research outputs found
Improving the performance of MIMO Relay Networks using Parallel Relays
No full textIn this thesis, we focus on improving the performance of MIMO relay communication systems using parallel relays and successive interference cancellation. We aim at minimising the mean-squared error of the signal waveform estimation at the destination node subjecting to transmit power constraints at the source and relay nodes. The joint source and relay matrices optimisation problems for parallel MIMO relay systems are highly nonconvex. We transform the problems into suitable forms which can be efficiently solved using standard convex optimization techniques. Both linear and nonlinear transceivers have been considered. The proposed algorithms have a significant performance improvement over the earlier approaches
Optimal Relay Design of Zero Forcing Equalization for MIMO Multi Wireless Relaying Networks
No full textIn this paper, we develop the optimal relay design for multiple-input multiple-output (MIMO) multi wireless relaying networks, when we consider the problem of zero-forcing processing is studied for multi-input multi- output multi-relay communication system in which MIMO source-destination pairs communicate simultaneously. It is assumed that due to severe shadowing effects which communication links can be established only with the aid of relay node. The aim is to design the relay amplification matrix to maximize the achievable communication sum- rate through the relay, which in general amplifying-and- forward relaying mechanisms are considered. The zero forcing (ZF) algorithm has studied for a MIMO multi relay network by comparing its performance in terms of bit- error-rate (BER) at destination algorithm. In particular, we investigate its performance with and without using the ZF at the relay. Our results demonstrate that the system performance can be significantly improved by using the ZF algorithm at relay (optimal relay ZF algorithm)</jats:p
Investigating Successive Interference Cancellation in MIMO Relay Network
No full textIn this paper, we study the zero-forcing (ZF) and minimum mean-squared error (MMSE) algorithms for a multiple-input multiple-output (MIMO) relay network and compare their performance in terms of bit-error-rate (BER). In particular, we investigate their performance with and without using the successive interference cancellation (SIC) at the receiver. Our results demonstrate that the system performance can be significantly improved by using the SIC technique
Investigating Performance Zero-Forcing of Source Weighting Matrix in MIMO Relay Communication
No full textIn this paper, we study the zero forcing (ZF) algorithm fora two hop multiple-input multiple-output (MIMO) relaycommunication system consisting of one source node, onerelay node, and one destination node. We consideramplify-and-forward (AF) strategy at relay node anddestination node, respectively. We propose Pre-ZFequalization on the transmitter side. We have evaluatedthe proposed system by comparing with existingalgorithms. The proposed Pre-ZF equalization algorithmhas a significant improvement in the system bit-error-rate(BER) performance
Analisis Efektivitas Manajemen Proyek Infrastruktur di Dinas Pekerjaan Umum Perumahan Rakyat Kabupaten Nabire
No full textPentingnya manajemen proyek infrastruktur dalam mendukung pembangunan daerah. Hal ini mencakup tantangan yang dihadapi oleh Dinas PUPR Kabupaten. Penelitian ini bertujuan untuk menganalisis efektivitas manajemen proyek yang dilaksanakan oleh Dinas PUPR untuk mengidentifikasi faktor-faktor yang berkontribusi terhadap keberhasilan atau kegagalan proyek infrastruktur. Penelitian ini menggunakan pendekatan campuran (mixed methods), yang mengombinasikan metode kuantitatif dan kualitatif. Data dikumpulkan melalui kuesioner yang disebarkan kepada staf Dinas PUPR dan wawancara mendalam dengan pejabat terkait. Analisis statistik dilakukan untuk mengevaluasi data kuantitatif, sedangkan analisis tematik digunakan untuk data kualitatif. Metode ini bertujuan untuk memberikan gambaran yang komprehensif mengenai efektivitas manajemen proyek infrastruktur. Hasil penelitian menunjukkan bahwa efektivitas manajemen proyek dipengaruhi oleh beberapa faktor, termasuk perencanaan yang matang, pengelolaan risiko, serta keterlibatan masyarakat dalam proses pembangunan. Data menunjukkan bahwa 75% responden menganggap bahwa proyek infrastruktur yang dilaksanakan oleh Dinas PUPR memiliki tingkat efektivitas yang tinggi, namun masih terdapat tantangan terkait keterlambatan dan pembengkakan biaya pada beberapa proyek. Selain itu, hasil analisis juga mengungkapkan bahwa komunikasi yang baik antara semua pemangku kepentingan berkontribusi positif terhadap keberhasilan proyek. Kesimpulan dari penelitian ini menekankan pentingnya penerapan prinsip-prinsip manajemen proyek yang baik dan keterlibatan aktif dari semua pihak terkait untuk meningkatkan efektivitas proyek infrastruktur di Dinas PUPR Kabupaten Nabire. Penelitian ini juga merekomendasikan agar Dinas PUPR terus mengembangkan sistem monitoring dan evaluasi yang lebih efektif untuk proyek-proyek mendatang, serta meningkatkan pelatihan bagi staf mengenai manajemen proyek yang efisien. Hasil penelitian ini diharapkan dapat memberikan kontribusi bagi pengembangan kebijakan dan praktik manajemen proyek di tingkat lokal
Joint source and relay design for MIMO multi-relay systems using projected gradient approach
No full textIn this paper, we develop the optimal source precoding matrix and relay amplifying matrices for non-regenerative multiple-input multiple-output (MIMO) relay communication systems with parallel relay nodes using the projected gradient (PG) approach. We show that the optimal relay amplifying matrices have a beamforming structure. Exploiting the structure of relay matrices, an iterative joint source and relay matrices optimization algorithm is developed to minimize the mean-squared error (MSE) of the signal waveform estimation at the destination using the PG approach. The performance of the proposed algorithm is demonstrated through numerical simulations
Direction of Denmark Analysis and Possibilities on the Example of Cargofast OÜ
No full textKäesoleva diplomitöö eesmärgiks oli leida viise Cargofast OÜ Kesk-Euroopa veosuuna kasumlikkuse suurendamiseks. Autor analüüsis kahe kliendi Taani eksportkoormate veomarsruute kasutades Lätist või Leedust väljuvaid laevaliine ning tehtud mittestruktueeritud intervjuusid Cargofast OÜ ning Samru Trans OÜ juhtkonnaga. Uuringu käigus selgitas autor välja, et veosuunal Sõmerpalu – Skaerbaek on kõige soodsam kasutada laevaliini Klaipeda-Kiel. Antud laeva kasutades on veoaeg neli päeva ning transpordikulud kokku Cargofast OÜ-le 1242,7 eur. Veosuunal Põlva – Vinderup on kõige soodsam minna laevaga Ventspils – Travemünde. Antud laevaga minnes on veoaeg viis päeva ning transpordikulud kokku Cargofast OÜ-le 1306,85 eur. Cargofast OÜ on kasutanud Taani veosuunal tavaliselt Lätist väljuvaid laevaliine. Autor leidis, et Sõmerpalust Toftan AS-st Taani Skaerbaeki laadides nädala alguses ning kasutades Klaipeda – Kiel laevaliini suureneb brutokasum võrreldes Ventspils – Travemünde laevaliiniga 3,2%. Ühe kuuga suureneks brutokasum vedades iga nädal ühe koorma kasutades Klaipeda – Kiel nädala alguses väljuvat laevaliini 12,8% ning aastas 153,6%. Võrreldes Liepaja – Travemünde laevaliigiga oleks brutokasum suurem kasutades Kliapeda – Kiel väljumist 8,6%. Ühe kuuga suureneks brutokasum vedades iga nädal ühe koorma kasutades Klaipeda – Kiel nädala alguses väljuvat laevaliini 34,4% ning aastas 412,8%. Klaipeda – Kiel laevaliin tõstab Cargofast OÜ veoaegadest kinnipidamist. Põlvast AS Pinest-st laadides esmaspäeval ning kasutades Klaipeda – Kiel laevaliini suureneks kasum võrreldes Liepaja – Travemünde laevaliiniga 3%. Ühe kuuga suureneks brutokasum vedades iga nädal ühe koorma kasutades Klaipeda – Kiel nädala alguses väljuvat laevaliini 12% ning aastas 288%. Autorile oli ette antud aastaringselt ekspordihinnad AS Pinest-st ning Toftan AS-st. Autor analüüsis, millise kliendiga teeniks rohkem brutokasumit. See ei tähendanud, et ettevõte peaks loobuma teisest kliendist vaid see on otsuste tegemisel oluline teada. Kõige tulutoovamaks Cargofast OÜ-le osutus Sõmerpalu – Klaipeda – Kiel – Skaerbaek veosuund nädala alguses laadimisega. Võrreldes Põlva – Ventspils – Travemünde – Vinderup veosuunaga osutus brutokasum 17% suuremaks Cargofast OÜ-le. Ühe kuuga suureneks brutokasum eelistades Sõmerpalu – Klaipeda – Kiel – Skarebaek laevaliini 68% ning aastas 816%. Autor eelistaks vedada rohkem Sõmerpalus asuvat Toftan AS klienti. Mittestruktueeritud intervjuudest Cargofast OÜ ning Samru Trans OÜ juhatuse liikmetega selgus, et Taani liinidega ollakse rahul. Taani liinid on kujunenud Cargofast OÜ Kesk – Euroopa veosuuna stabiilseimaks ning kasumlikumaks osaks. Pidevalt on vaja küsida erinevate laevaliinide hinnapakkumisi, et olla kursis laevapileti hindadega, sest hinnad muutuvad aastas mitmeid kordi. Käesoleva lõputööga selgitas autor välja ettevõtte Cargofast OÜ veokulud vedades kahe kliendi eksportkoormaid Taani mandrile ning pakkus välja võimalikke uusi lahendusi.Direction of Denmark analysis and possibilities on the example of Cargofast OÜ. The aim of this thesis was to find ways how to increase profitability for Cargofast OÜ in direction of Central Europe. By the analysis of two customers based on Denmark export loads transport routes and using Latvia or Lithuania outgoing shipping services, also unstructured interviews carried with Cargofast OÜ and Samru Trans OÜ management. During the study the author explained that the trailing direction Sõmerpalu – Skaerbaek is the most profitable when using shipping road called Klaipeda-Kiel. When using this particular ship the transportation time is only four days and the shipping cost for Cargofast OÜ is 1242,7 eur. The shipping direction Põlva - Vinderup is most advantageous when using the ship Ventspils - Travemünde. When going by this road the transportation time is five days and transport costs all together for Cargofast OÜ 1306,85 eur. Typically Cargofast OÜ has used in Denmark trailing direction ships that were outgoing from Latvian shipping services. The author found that loading from Sõmerpalu Toftan AS to Denmark Skaerbaek at the beginning of the week and using Klaipeda - Kiel shipping services, the total gross profit increases 3,2% compared to Ventspils - Travemünde shipping route. In one month gross profit would increase each week when carrying loads using Klaipeda - Kiel at the beginning of the week, the outgoing shipping services 12,8% and 153,6% a year. Compared to Liepaja - Travemünde marine species have a higher gross profit using Kliapeda - Kiel departure of 8,6%. In one month gross profit would increase each week while carrying a load using Klaipeda - Kiel at the beginning of the week outgoing shipping services 34,4% and 412,8% a year. Klaipeda - Kiel shipping service raises Cargofast OÜ times of the carriage. Loading from Põlva AS Pinest On Monday and using Klaipeda - Kiel increase in earnings compared to the shipping Liepaja - Travemünde shipping route 3%. In one month, it would increase gross profit each week while carrying a load using one of Klaipeda - Kiel at the beginning of the week the outgoing shipping line by 12% and 288 % per year. The author was a given year - round export prices from the AS Toftan and Pinest AS. By the analysis, author found out which client would earn more gross profit. This doesnt mean that the company should give up other clients but it is important knowledge during decision making. The most profitable line for Cargofast OÜ was Sõmerpalu - Klaipeda - Kiel - Skaerbaek direction when loading at the beginning of the week. Compared Põlva - Ventspils - Travemünde - Vinderup trailing direction gross profit was 17% higher for Cargofast OÜ. In one month the gross profit would possibly increase when preferring Sõmerpalu - Klaipeda - Kiel - Skarebaek shipping line by 68% and 816% per year. The author would prefer to carry more its client Toftan AS that is located in Sõmerpalu. During unstructured interviews with Cargofast OÜ and Samru Trans OÜ board members turned out that they were satisfied with the Danish lines. The Danish lines are the most stable and profitable part for Cargofast – Central European transportation direction. There is a constant need to ask for quotes from various shipping lines, in order to be familiar with the ferry ticket prices, because prices change several times a year . In this thesis the author explained Cargofast OÜ shipping costs when delivering export loads from Estonia to Denmark for two customers, and suggested possible new solutions
Joint source and relay optimization for parallel MIMO relays using MMSE-DFE receiver
No full textIn this paper, we study the optimal structure of the source precoding matrix and the relay amplifying matrices for multiple-input multiple-output (MIMO) relay communication systems with parallel relay nodes. In particular, a nonlinear decision feedback equalizer (DFE) is used at the destination node, and the minimal mean-squared error (MMSE) criterion is used to detect the transmitted signal at each stream. We show that the optimal source precoding matrix and the optimal relay amplifying matrices have a beamforming structure. Using such optimal source and relay matrices and the MMSE-DFE receiver, a joint source and relay power loading algorithm is developed to minimize the MSE of the signal waveform estimation. Compared with existing algorithms for parallel MIMO relay networks, theproposed source and relay design together with the MMSE-DFE receiver has a significant improvement in the system bit-errorrate performance
The Cost-Benefit Analysis of Logistics Services for VMV Lines OÜ
No full textKäesoleva diplomitöö keskeks teemaks on teenuste sisseostmine ning isikliku autopargi omamine. Diplomant võrdleb neid kahte strateegiat eesmärgiga välja pakkuda edasine arengusuund väikeettevõttele VMV Lines OÜ-le, mis pakub veoteenust omades isklikku väikest autoparki. Töö esimene pool on teoreetiline, mis on esitatud teises peatükis, kus tutvustatakse transpordi olemust ning selgitatakse, mida tähendab teenuste sisseostmine ning isikliku autopargi omamine. Lisaks tuuakse välja iskliku autopargi omamise eelised ning puudused. Lisaks teoreetilisele arutlusele viiakse läbi samalaadsete ettevõtete majandusaasta aruannete analüüs kolmandas peatükis. Lähtuvalt nendest tulemustest arutleb autor VMV Lines OÜ tuleviku aregusuundade üle neljandas peatükis. Lähtudes teooriast ning praktilisest juhtumist järeldab diplomant, et efektiivseks majandamiseks on VMV Lines OÜ-l tarvis suurenada autoparki, eeldusel, et kulude üle on kontroll. Lisaks soovitab diplomant tegeleda ka lisaks ekspedeerimisega, kuna omakulud on sel juhul väga väikesed. Eelduseks on heade ja usaldusväärsete koostööpartnerite leidmine. Ettevõttel VMV Lines OÜ on arenguruumi võttes arvesse antud töös võrreldud ettevõtteid. Eeskujuks saaks kasutada ettevõtte EKA Veod finantsanalüüsi. Kindlasti tuleks investeerida müüki ning turundusse ja selleks saaks kasutada võõrkapitali, sest ettevõttel kohustused puuduvad. Arvesse tuleb võtta ka ühe tonni efektiivsuskalkulatsioonid, kust paistis selgelt välja, et mitu ettevõtet (EKA Veod, Finnic ning Deston Cargo) kasutavad veokeid efektiivsemalt kui praegu VMV Lines OÜ. Müügimahu suurenedes tuleb arvestada kindlasti ka veokite ning töötajate lisandumisega ja seetõttu ka lisakuludega. Võttes arvesse EKA Veod OÜ näitajaid, saame öelda et õige käibekapitali juhtimise korral on võimalik likviidsust väga kõrgel tasemel hoida. Ka rentaabluse näitajaid on võimalik müügimahu suurendades kasvatada, jättes püsikulud praegusele tasemele. Hindade tõstmine võib olla üks lahendus müügitulu suurendamisel ning rentaabluse näitajate parandamisel, aga efekt võib osutuda ka vastupidiseks, kui hindu tõsta liiga suurel määral. Hindu saaks tõsta mõõdukalt 3-5% ning diferentseerida seda erinevate klientide vahel. Selline muutus kataks ära iga-aastase inflatsiooni ning tagaks olemasoleva kliendibaasi säilimise. Antud töö näitab ka seda, et olenemata väga tihedast konkurentsist, veonduse turul, on võimalik siiski saavutada uutel ettevõtetel häid tulemusi, sest nõudlus endiselt eksisteerib. Turul on ka kindlasti mitmeid kasutamata nišše, et saavutada konkurentsieelis teiste ettevõtete ees. Veondus on küll väga sarnane erinevate ettevõtete vahel, aga võimalik on pakkuda lisaks veoteenusele ka muid lisahüvesid oma klientidele, mis tekitavadki konkurentsieelise. Teenusepakkujatena on kindlasti väga oluline klienditeenindus ja suhtlus, millega on võimalik välja paista teiste ettevõtete seast. Tiheda konkurentsi tõttu eelistatakse partnereid, keda saab lisaks heale veoteenusele ka usaldada ning kellega on meeldiv suhelda.The main topic of this paper is out-sourcing and owning a car fleet. The author compares these two strategies in order to propose the future strategy for small enterprise VMV Lines OÜ, which provides transport service and owns currently a small fleet. The first part of the paper is theoretical and it is presented in the second paragraph, which introduces the nature of transport and explains what means out-sourcing and owning a car fleet. In addition, the advantages and disadvantages of owing a personal car fleet are introduced. In addition to the theoretical discussion, the author carries out an analysis of annual reports of transport companies in the third chapter. Based on the results, the author proposes the future strategies for VMV Lines OÜ. The results indicate that for effective management, VMV Lines OÜ must increase the fleet but at the same time the costs need to be under strict control. In addition, the author suggest for the company in question to provide the expediting service, which means providing service through a third party. The reason for this suggestion is that the costs of providing this kind of service are very low. The precondition is finding trustworthy partners. The analysis of VMV Lines OÜ annual report shows that the company has room to grow. A good example is a company EKA Veod OÜ. According to the economic analysis VMV Lines OÜ should invest in sales and marketing while using external finance, because in that case the company does not have any obligations. The efficacy estimates per ton should also be taken into account, which showed that several companies in the analysis (EKA Veod, Finnic and Deston Cargo) use their fleet more efficiently than VMV Lines OÜ. It should be kept in mind that the increase of sales volume needs more fleet and labor, therefore increased costs. Taking into account the indicators of EKA Veod OÜ, it can be said that the proper capital management enables to keep a high level of liquidity. Additionally, there is room to grow the profitability indicators while keeping the fixed costs at the same level. The increase of prices could be one of the solutions to increase the revenues and improve the profitability indicators. On the other hand the effect of that could result the opposite results if the prices are increased too much. The moderate increase of prices is around 3-5% and this should be differentiated between the customers. That increase would also cover the yearly inflation and ensures the existence of current customers. The paper shows that, despite of the high competition in the transport market it is possible to achieve good economic results if there is still demand for the service. There are still unused niches in the market, which could be used as a competition edge. Although transportation services are rather similar in the market, there is possibility to offer other additional benefits to the customers, which create the competition edge. As a service provider it is important to have good customer service and relations, which makes it possible to differ from others in the same market. Because of the high competition the customers value transport service that is trustworthy and has good and pleasant communication
Joint source and relay optimization for parallel MIMO relay networks
No full textIn this article, we study the optimal structure of the source precoding matrix and the relay amplifying matrices for multiple-input multiple-output (MIMO) relay communication systems with parallel relay nodes. Two types of receivers are considered at the destination node: (1) The linear minimal mean-squared error (MMSE) receiver; (2) The nonlinear decision feedback equalizer based on the minimal MSE criterion. We show that for both receiver schemes, the optimal source precoding matrix and the optimal relay amplifying matrices have a beamforming structure. Using such optimal structure, joint source and relay power loading algorithms are developed to minimize the MSE of the signal waveform estimation at the destination. Compared with existing algorithms for parallel MIMO relay networks, the proposed joint source and relay beamforming algorithms have significant improvement in the system bit-error-rate performance
