Kavramsal Değişim Yaklaşımına Dayalı Öğretim Yoluyla Öğrencilerin Kimyasal Reaksiyonlar ve Enerji Kavramlarının Geliştirilmesi

This study was designed to investigate the effectiveness of the conceptual change oriented instruction through demonstration over traditionally designed chemistry instruction on 10th grade students’ understanding of chemical reactions and energy concepts and their attitudes towards chemistry as a school subject. One of the groups was defined as control group in which students were taught by traditionally designed chemistry instruction (TDCI), while the other group defined as experimental group in which students were instructed by conceptual change oriented instruction through demonstrations (CCID). The results showed that CCID caused significantly better acquisition of the scientific conceptions related to chemical reactions and energy concepts than TDCI. Also, the results showed that there was a significant difference between post-test mean scores of students taught with CCID and those taught with TDCI with respect to their attitude toward chemistry as a school subject in favor of CCID.Bu çalışma, kavramsal değişime dayalı öğretim yönteminin kullanımının 10. sınıf öğrencilerinin kimyasal reaksiyonlar ve enerji konularındaki kavramları anlamalarına ve öğrencilerin kimyaya karşı olan tutumlarına etkisini geleneksel kimya öğretim yöntemi ile karşılaştırarak incelemek için tasarlanmıştır. Gruplardan bir tanesi kontrol grubu olarak tanımlanmış ve bu gruba geleneksel öğretim yöntemi uygulanmış, diğer grup ise deneysel grup olarak tanımlanmış ve bu grupta kavramsal değişim yaklaşımına dayalı öğretim yöntemi uygulanmıştır. Sonuçlar kavramsal değişim yaklaşımı kullanılan öğrencilerin, kimyasal reaksiyonlar ve enerji kavramlarını, geleneksel kimya anlatımı kullanılan gruba göre daha iyi anladıklarını göstermektedir. Ayrıca, sonuçlar öğrencilerin kimyaya karşı tutumlarına göre değerlendirildiğinde, kavramsal değişim yaklaşımı kullanılan grubun son-test ortalaması ile geleneksel kimya anlatımı kullanılan grubun son-test ortalaması arasında, kavramsal değişim yaklaşımı kullanılan grubun lehine anlamlı bir farklılık olduğu görülmektedir.  

Design of a ROIC for scanning type HgCdTe LWIR focal plane arrays

Design of a silicon readout integrated circuit (ROIC) for LWIR HgCdTe Focal Plane is presented. ROIC incorporates time delay integration (TDI) functionality over seven elements with a supersampling rate of three, increasing SNR and the spatial resolution. Novelty of this topology is inside TDI stage; integration of charges in TDI stage implemented in current domain by using switched current structures that reduces required area for chip and improves linearity performance. ROIC, in terms of functionality, is capable of bidirectional scan, programmable integration time and 5 gain settings at the input. Programming can be done parallel or serially with digital interface. ROIC can handle up to 3.5V dynamic range with the input stage to be direct injection (DI) type. With the load being 10pF capacitive in parallel with 1MΩ resistance, output settling time is less than 250nsec enabling the clock frequency up to 4MHz. The manufacturing technology is 0.35μm, double poly-Si, four-metal (3 metals and 1 top metal) 5V CMOS process

Realization of a ROIC for 72x4 PV-IR detectors

Silicon Readout Integrated Circuits (ROIC) for HgCdTe Focal Plane Arrays of 1x4 and 72x4 photovoltaic detectors are represented. The analog circuit blocks are completely identical for both, while the digital control circuit is modified to take into account the larger array size. The manufacturing technology is 0.35μm, double poly-Si, three-metal CMOS process. ROIC structure includes four elements TDI functioning with a super sampling rate of 3, bidirectional scanning, dead pixel de-selection, automatic gain adjustment in response to pixel deselection besides programmable four gain setting (up to 2.58pC storage), and programmable integration time. ROIC has four outputs with a dynamic range of 2.8V (from 1.2V to 4V) for an output load of 10pF capacitive in parallel with 1MΩ resistance, and operates at a clock frequency of 5 MHz. The input referred noise is less than 1037 μV with 460 fF integration capacitor, corresponding to 2978 electrons

Realization of readout integrated circuit (ROIC) for an array of 72x4, P-on-N type HgCdTe long wave infrared detectors

Infrared Focal Plane Arrays (IRFPAs) are important and high-tech systems, which are used in many strategic applications, such as medical imaging, missile guidance, and surveillance systems. The most important building blocks of IRFPAs are detectors and Readout Integrated Circuit (ROIC). Both of them need careful design and implementation for the overall system to be succesful. Detector part produces the photon induced current and sent to the input of ROIC. Detector design and fabrication determines the operating wavelength and main noise performance of the imaging system. On the other hand, ROIC is the interface element between the detector and microcomputer of the IRFPA system, and determines important performance parameters of the overall system; such as linearity, dynamic range, injection efficiency, noise performance (less effective than detector), and power consumption. Therefore it is important to design and implement a ROIC, that fits best to the desired application. In this thesis, a CMOS ROIC is designed and implemented for scanning type of 72×4 Pon- N HgCdTe detector array in 0.35 μm, 4 metal 2 poly AMS CMOS process. Current Mirror Integration (CMI) is used as the unit cell of the ROIC. For the signal processing, Time Delay Integration (TDI) over 4 elements with an optical supersampling rate of 3 is used for improved Signal-to-Noise Ration (SNR). The designed and implemented ROIC has the properties of bidirectional scanning, variable integration time, adjustable gain settings, bypass functionality, automatic gain adjustment, and pixel selection/deselection functionality. ROIC is programmable through a serial and a parallel interface. Gain settings, TDI scanning direction, information of mulfunctioning pixels, ROIC operation mode (test or TDI) can be programmed by using these interfaces. Operating frequency of the ROIC is up to 5 MHz, while the dynamic range is 2.8 V

Digital readout integrated circuit (DROIC) implementing time delay and integration (TDI) for scanning type infrared focal plane arrays (IRFPAs)

This thesis presents a digital readout integrated circuit architecture implementing time delay and integration with an oversampling rate of 2 for scanning type infrared focal plane arrays with a charge handling capacity of 44.8 Me- while achieving quantization noise of 198 e- and power consumption of 14.5 mW. Conventional pulse frequency modulation method is supported by a single slope ramp ADC technique to have very low quantization noise together with a low power consumption. The proposed digital TDI ROIC converts the photocurrent into digital domain in two phases; in the first phase, most significant bits are generated by conventional PFM technique in the charge domain, while in the second phase least significant bits are generated by the single slope ramp ADC in the time domain. A 90x8 prototype has been fabricated and verified, showing a significantly improved signal-to-noise ratio of 51 dB for the low illumination levels (280,000 collected electrons), which is attributed to the TDI implementation method and very low quantization noise due to the single slope ADC. The proposed digital TDI ROIC proves the benefit of digital readouts for the scanning arrays enabling smaller pixel pitch, better SNR for low illumination levels and lower power consumption compared to the analog TDI readouts

CBS İÇİN KONUMSAL VERİLERİN ELDE EDİLMESİNDE GZK GPS YÖNTEMİNİN KLASİK JEODEZİK YÖNTEME GÖRE DOĞRULUK VE MALİYET ANALİZLERİNİN KARŞILAŞTIRILMASI

Coğrafi Bilgi Sistemi ( CBS ) çalışmalarında; konumsal verilerin elde edilmesi büyük öneme sahiptir. Çünkü CBS projelerinin başarıya ulaşması, elde edilen konumsal verilerin, oluşturulan CBS projesinin gerektirdiği doğrulukta ve güncellikte olmasına bağlıdır. Bu, sınırlı olan ülke kaynaklarının israf edilmemesi açısından önemlidir. CBS oluşturulmasında konumsal verilerin elde edilmesinde kullanılan yöntemlerin karşılaştırılması amacıyla S.Ü. Kampus alanı içinde yaklaşık 20 ha’lık bir test alanı oluşturulmuştur. Bu test alanı içine giren bütün detay noktalarının koordinatları kutupsal alım yöntemiyle (Elektronik Takeometre ile) ve GZK GPS (Gerçek Zamanlı Kinematik Global Konum Belirleme ) yöntemiyle elde edilmiştir. Kutupsal alım yöntemi ( Klasik yöntem ) referans kabul edilerek, GZK GPS yöntemiyle elde edilen konumsal verilerin doğruluk ve maliyet analizi yapılmıştır. Amprik test ve hesaplamalar sonucunda GZK GPS’de konum ortalama hatası mp=±7.2 cm olarak elde edilmiştir. Birim maliyet ( 1 ha ), klasik yöntemde 95.86 $, GZK GPS’de 17.22$ olarak hesaplanmıştır. Bu araştırmanın bir sonucu olarak, oluşturulacak CBS’nin amacına uygun olarak her bir yöntem ayrı ayrı olarak kullanılabileceği gibi birlikte de kullanılabilir

DİJİTAL ORTOFOTO HARİTALARDA KONUM DOĞRULUĞU VE MALİYET KARŞILAŞTIRMASI

In Geographic Information System ( GIS ) studies, spatial data obtained has been of greatimportance. The achievement of GIS projects is dependent upon the accuracy and spatial data updated.This is vital in terms of extravagant waste of national sources. The test area about 20 ha has beenestablished in Selcuk University Campus to compare spatial data for GIS. All detail points covering thetest area have been measured by polar coordinate method using electronic tachymetry and obtainedsame coordinates with Digital Orthophoto production Method. Polar coordinate method (classicalmethod) has been accepted as a reference and it has been compared with the spatial data obtained fromdigital orthophoto method in view of accuracy and cost. The root mean square (RMS) errors obtainedfrom comparisons have been found as mp=±53.7cm for digital orthophoto production method. The unitcost (1 ha) is 95.86 $for classical method, 21.93$ for digital orthophoto production method.Coğrafi Bilgi Sistemi (CBS) çalışmalarında; konumsal verilerin elde edilmesi büyük önemesahiptir. CBS projelerinin başarıya ulaşması, elde edilen konumsal verilerin, oluşturulan CBS projesiningerektirdiği doğrulukta ve güncellikte olmasına bağlıdır. Bu, sınırlı olan ülke kaynaklarının israfedilmemesi açısından önemlidir. CBS için konumsal verileri karşılaştırmak amacıyla Selçuk Üniversitesi(S.Ü.) Kampus alanı içinde yaklaşık 20 ha’lık bir test alanı oluşturulmuştur. Bu test alanı içine girenbütün detay noktalarının koordinatları kutupsal alım yöntemiyle (Elektronik Takeometre ile) ve dijitalortofoto görüntü üzerinden koordinatlar okunarak elde edilmiştir. Kutupsal alım yöntemi (Klasikyöntem) referans kabul edilerek, dijital ortofotodan elde edilen konumsal verilerin doğruluğubelirlenmeye çalışılmış ve her iki yöntem maliyet yönünden karşılaştırılmıştır. Dijital ortofotodan eldeedilen konum ortalama hatası mp=±53.7cm olarak bulunmuştur. Birim maliyet (1 ha), klasik yöntemde95.86 $, dijital ortofoto yönteminde ise 21.93$ olarak hesaplanmıştır

Digital pixel readout integrated circuit architectures for LWIR

This paper presents and discusses digital pixel readout integrated circuit architectures for long wavelength infrared (LWIR) in CMOS technology. Presented architectures are designed for scanning and staring arrays type detectors respectively. For scanning arrays, digital time delay integration (TDI) is implemented on 8 pixels with sampling rate up to 3 using CMOS 180nm technology. Input referred noise of ROIC is below 750 rms electron meanwhile power dissipation is appreciably under 30mW. ROIC design is optimized to perform at room as well as cryogenic temperatures. For staring type arrays, a digital pixel architecture relying on coarse quantization with pulse frequency modulation (PFM) and novel approach of extended integration is presented.. It can achieve extreme charge handling capacity of 2.04Ge(-) with 20 bit output resolution and power dissipation below 350 nW in CMOS 90nm technology. Efficient mechanism of measuring the time to estimate the remaining charge on integration capacitor in order to achieve low SNR has employed

Low-power LVDS for digital readout circuits

This paper presents a mixed-signal LVDS driver in 90 nm CMOS technology. The designed LVDS core is to be used as a data link between Infrared Focal Plane Array (IRFPA) detector end and microprocessor input. Parallel data from 220 pixels of IRFPA is serialized by LVDS driver and read out to microprocessor. It also offers a reduced power consumption rate, high data transmission speed and utilizes dense placement of devices for area efficiency. The entire output driver circuit including input buffer draws 5mA while the output swing is 500mV at power supply of 1.2V for data rate of 6.4Gbps. Total LVDS chip area is 0.79 mm(2). Due to these features, the designed LVDS driver is suitable for purposes such as portable, high-speed imaging