44 research outputs found

    Microstrip Antennas for Indoor Wireless Dynamic Environments

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    Local residents and tourists’ opinion on the effects of boating activity towards Kilim waterways

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    Heritage sites within Kilim Karst Geoforest Park consist of geology, archaeology, ecology, history and culture. Therefore, both tourism and resource conservation should be integrated in order to benefit human and natural resources. This paper presents research that identifies the opinion of tourists and local residents on the effects of boating activities towards natural resource conservation in Kilim Karst Geoforest Park, Langkawi. 320 structured questionnaires were distributed to tourists, local residents in Kilim and staffs who are in charged in the tourism operation of Kilim Karst Geoforest Park including staff of Langkawi Development Authority (LADA), Koperasi Kampung Kilim Langkawi Berhad (KKKLB) and Komuniti Pengurusan Sumber Perikanan (KPSP). The study managed to gather 93% with response rate (n=299) that consist tourists (65), local residents of Kilim (145) and staff (89). Based on the analyses conducted, it was found that boating activities contributed to the pollutions along Kilim waterways in many ways for instance, oil spills and waste disposals. Majority of the respondents agreed that high boats speed increased strong waves, which lead to depletion of mangrove trees and affecting aquatic life. Kilim has become one of the preferred destinations for nature lovers since the area has been given the Geopark and has received countless of tourist arrivals. Nevertheless, this situation had also affected natural resources of the area. Thus, people who involved in tourism activities and the management of Kilim Karst Geoforest Park should concern and possessed adequate knowledge on natural resource conservation so that the area can be experienced by the future generations

    5G Hairpin and Interdigital Bandpass Filters

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    At two low 5G frequency bands: 3.7 GHz - 4.2 GHz and 5.975 GHz -7.125 GHz, Hairpin Bandpass Filter (HPBF) and Interdigital Bandpass Filter (IBF) are designed and simulated in this paper. Both filters show good results in terms of matching and transmission responses with a wide bandwidth through the two frequency bands. HPBF with simple design resulted in good return and insertion losses, < - 10.43 dB and – 0.63 dB, and < - 14.48 dB and –0.46 dB through frequency bands: 3.51 GHz - 4.27 GHz and 5.58 GHz – 7.24 GHz, respectively. In addition to good filter response that IBF provides, it supports high order second harmonics suppression. The simulated S11 and S12 of this filter are < -11.15 dB and –0.63 dB with out of band rejection up to 11.12 GHz through the frequency band 3.56  GHz – 4.25 GHz. Furthermore, at the second frequency band IBF is designed with two different grounding via hole radii (rVia), case 1: rVia = 0.4 mm and case 2: rVia = 0.7 mm. For both cases, the designed filter shows good results with high order second harmonics suppression up to 18.33 GHz and 18.96 GHz. In this paper, High Frequency Structure Simulator (HFSS) software is used to carry out the simulation

    Isu dan Cabaran Pelaksanaan Pendidikan Asas Vokasional (PAV) di Sekolah Menengah Harian, Malaysia

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    Kertas konsep ini membincangkan pelbagai isu berkaitan mata pelajaran baru di sekolah menengah akademik yang dikenali sebagai Pendidikan Asas Vokasional (PAV) yang baru dilaksanakan pada tahun 2013. PAV merupakan matapelajaran berasaskan kompetensi (Competency Based Education/ CBE) yang merangkumi pelaksanaan pengajaran dan pembelajaran serta pentaksiran berasaskan keterampilan. Justeru, fokus utama kertas ini ialah untuk mengupas mengenai isu serta cabaran terhadap pelaksanaan PAV daripasa aspek penyediaan dan latihan guru, proses pengajaran dan pembelajaran, penyediaan sumber, bahan dan peralatan, serta sistem penilaian dan pentaksiran. Adalah diharapkan kertas konsep ini dapat memperluaskan perspektif dan pemahaman terhadap berbagai isu berkaitan dengan proses pelaksanaan program PAV di sekolah-sekolah menengah harian biasa di Negara ini

    Miniaturized 4 x 4 switched-beam butler matrix with bandwidth enhancement for 5G communication system

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    A 4 x 4 Butler Matrix (BM) without phase shifter is proposed to provide bandwidth enhancement and size reduction by removing a conventional 0 dB/90⁰ crossover, two 0⁰ phase shifters and two 45 phase shifters. Two proposed 3 dB/45⁰ patch couplers replace the combination of two conventional 3 dB/90⁰ branch-line couplers and two 45⁰ phase shifters, whilst a modified0 dB/0⁰ crossover removes two 0⁰ phase shifters from the conventional BM. The -10 dB fractional bandwidths of reflection coefficients and isolations for the proposed BM are 18.46% in simulation and measurement. The -6 dB ± 1.5 dB average transmission coefficient and +45⁰, �135�, +135⁰and +45⁰ of output phase differences with 1.8� average phase imbalance are accomplished at 6.5 GHz. The simulated and measured scattering parameters (S parameters) and phase differences are in close compliance with each other. Four switched-beams pointed at +15⁰, -50⁰, +50⁰ and +15⁰ are developed by integrating the proposed BM with inset feeding patch antennas. The proposed BM is miniaturized by 51.56%, whilst the bandwidth performance is enhanced by 9.7% compared to the conventional BM. Hence, this compact BM is a promising candidate for the fifth generation (5G) communication system

    5G hairpin bandpass filter

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    In this paper, Hairpin Bandpass Filter (HPBF) is designed, simulated and fabricated at two 5G low-frequency bands: 3.7 GHz-4.2 GHz and 5.975 GHz-7.125 GHz. This filter will be a part of our 5G narrowband/ Ultra Wide Band (UWB) reconfigurable antenna project that plays a significant role in the recent wireless networks, such as Cognitive Radios (CRs). Through the two frequency bands, the filter resulted in good matching and transmission responses with enhanced bandwidth. The measured reflection coefficient of the proposed HBPF, S11 is <-10 dB and <-11.66 dB through 3.45 GHz – 4.25 GHz and 5.62 GHz – 7.6 GHz, respectively. However, the transmission coefficient, S12 is around-1.5 dB and – 1.17 dB at the center frequencies FC = 3.75 GHz and 6.61 GHz, respectively. In this paper, the High-Frequency Structure Simulator (HFSS) software is used to carry out the simulation. The full-wave simulation results are validated with the hardware measurements

    Aplikasi Konsep Dan Kaedah Lukisan Kejuruteraan Dalam Matematik Oleh Guru-Guru Matematik Di Sekolah Menengah Teknik Seluruh Negeri Kelantan

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    Penyelidikan ini adalah untuk mengkaji tahap pengetahuan dan aplikasi Lukisan Kejuruteraan dalam mata pelajaran matematik oleh guru-guru matematik di semua Sekolah Menengah Teknik di negeri Kelantan. Semua guru matematik telah digunakan sebagai sampel dalam kajian ini. Set soal selidik yang mengandungi dua bahagian iaitu berbentuk kuantitatif dan kualitatif digunakan bagi mendapatkan keputusan yang lebih menyeluruh. Data dianalisis secara manual dan dikemukakan dalam bentuk peratus. Hasil kajian menunjukkan guru tidak mempunyai pengetahuan tentang integrasi dua mata pelajaran tersebut, tahap apalikasi guru yang mempunyai pengalaman mengajar Lukisan Kejuruteraan adalah baik dan biodata guru seperti pengalaman mengajar dan kelulusan akademik tidak mempengaruhi pengetahuan dan aplikasi guru. Beberapa cadangan dikemukakan untuk memperbaiki kelemahan-kelemahan yang dikenalpasti, antaranya guru-guru perlu diberi pendedahan tentang konsep dan kaedah mengajar Lukisan Kejuruteraan. Di samping itu penyelarasan skema jawapan soalan matematik yang mempunyai kaitan secara langsung dengan Lukisan Kejuruteraan perlu dilakukan

    Radio access network power management considering radio over fiber technique for 4G mobile system

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    Radio over fiber technique was suggested as excelent candidates for 4G radio access network considering large number mobile users. With higher number of base stations, a microwave link presents more disadvantages across base stations in relation to power management, interference effect, atmosphere effects, and maintenance. In this paper, the radio over fiber power management technique is introduced. It transmits and receives signals with lower losses and dispersion effect through the fiber link. The signal quality is improved with the parameters optimization for practical applications. It proposed better power level for 4G mobile base stations with the expected coverage area, as well as power control and signal improvement for the system

    Active integrated antenna (AIA) with image rejection

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