Efficient Second-Order Plane Adjustment

Planes are generally used in 3D reconstruction for depth sensors, such as RGB-D cameras and LiDARs. This paper focuses on the problem of estimating the optimal planes and sensor poses to minimize the point-to-plane distance. The resulting least-squares problem is referred to as plane adjustment (PA) in the literature, which is the counterpart of bundle adjustment (BA) in visual reconstruction. Iterative methods are adopted to solve these least-squares problems. Typically, Newton's method is rarely used for a large-scale least-squares problem, due to the high computational complexity of the Hessian matrix. Instead, methods using an approximation of the Hessian matrix, such as the Levenberg-Marquardt (LM) method, are generally adopted. This paper challenges this ingrained idea. We adopt the Newton's method to efficiently solve the PA problem. Specifically, given poses, the optimal planes have close-form solutions. Thus we can eliminate planes from the cost function, which significantly reduces the number of variables. Furthermore, as the optimal planes are functions of poses, this method actually ensures that the optimal planes for the current estimated poses can be obtained at each iteration, which benefits the convergence. The difficulty lies in how to efficiently compute the Hessian matrix and the gradient of the resulting cost. This paper provides an efficient solution. Empirical evaluation shows that our algorithm converges significantly faster than the widely used LM algorithm

Analisis Pengaruh Konversi Hutan Terhadap Larian Permukaan Dan Debit Sungai Bulili, Kabupaten Sigi

Tidak dapat dipungkiri bahwa kebutuhan lahan untuk bidang pertanian dan perkebunan semakin mendesak seiring bertambahnya penduduk suatu wilayah dan juga akibat migrasi dari wilayah lain. Konsekuensinya adalah perambahan dan konversi hutan yang tidak dapat dielakkan, termasuk di daerah studi. Konversi hutan berakibat langsung dan tidak langsung pada perilaku hidrologis suatu kawasan atau Daerah Aliran Sungai (DAS) seperti menurunnya kemampuan air hujan terinfiltrasi ke dalam tanah akibat pemadatan tanah secara sistemik yang secara simultan meningkatkan larian permukaan (surface runoff) dan meningkatkan risiko banjir di musim hujan dan kekeringan di musim kemarau. Tujuan penelitian ini adalah untuk menganalisis dan mendapatkan besaran dan rasio limpasan langsung dan debit aliran sungai saat banjir dan saat air normal dengan membandingkan sub-DAS yang masih tertutup hutan asli dengan sub-DAS yang sudah beralih fungsi menjadi lahan terbuka dan pertanian/perkebunan. Dari hasil analisis dan simulasi data dapat disimpulkan bahwa konversi hutan berakibat pada meningkatnya volume larian permukaan dan debit aliran di Sungai Bulili sebesar 219.8 mm; dengan membandingkan total limpasan pada tahun 2002 dan 2004 pada bendung 2 (sub-DAS terkonversi) dan bendung 3 (sub-DAS hutan asli), walaupun curah hujan tercatat lebih kecil pada tahun 2002 dibandingkan dengan tahun 2004. Disamping itu, analisis terhadap beberapa kejadian banjir di daerah studi menunjukkan pola hidrograf dengan kenaikan debit yang tajam dan besar (koefisien kepencengan rerata 6.0) dengan waktu tiba banjir menjadi lebih pendek di sub-DAS terkonversi dengan waktu tiba banjir berkisar 25 – 30 menit pada bendung 1 dan berkisar 40 – 55 menit pada bendung 2. Rasio debit antara bendung 2 dan bendung 1 pada tahun 2002 adalah 2.33 meningkat menjadi 4.57 pada tahun 2004 dengan rasio banjir maksimum tercatat tahun 2002 sebesar 1.41 dam meningkat tahun 2004 sebesar 3.13

Biological Functions of Arabidopsis TGA1 and TGA4 Transcription Factors

Plant immune system comprises three main layers. Recognition of conserved microbe-associated molecular patterns (MAMPs) initiates the first layer of immune response, known as MAMP-triggered immunity (MTI). However successful pathogens utilize virulent strategies, such as effector proteins, to suppress MTI and facilitate their growth, resulting into effector-triggered susceptibility (ETS). In response to ETS, plants acquire resistance proteins (R proteins) to monitor the presence of the pathogen effector proteins, leading to stronger immune response, known as effector-triggered immunity (ETI). During the plant immune response, large-scale transcriptional reprogramming is activated by numerous transcription (co)factors. The Arabidopsis TGA factors have been shown to be required for resistance to disease. In the present study, the biological functions of clade I TGA factors (TGA1 and TGA4) during plant immune responses were investigated in depth. My results demonstrate that the Arabidopsis TGA1 and TGA4 are positive regulators in disease resistance against various types of pathogens. Multiple mutant alleles and overexpression lines of clade I TGA factors were identified and analyzed to confirm the previous finding that clade I TGA factors positively contribute to ETS against a virulent race of the bacterial pathogen Pseudomonas syringae and further discover their positive role in ETS against the fungal pathogen Colletotrichum higginsianum. In addition, clade I TGA factors were shown to play important roles in MTI-mediated disease resistance against P. syringae pv. tomato hrcC-, and ETI-mediated disease resistance against P.s.t. AvrRpt2. Furthermore, clade I TGA factors are required for non-host resistance against P. syringae pv. phaseolicola 1448a, wich relies on both MTI and ETI. Loss of resistance in mutants of clade I TGA factors was shown to be associated with defects in cell wall-based defence responses, including callose deposition, apoplastic oxidative burst and extracellular PR-1 protein accumulation. Interestingly, transcript levels of PR-1, callose synthase and other genes encoding defence proteins accumulated at, or above, wild type levels in the mutants. Furthermore, the double mutant is more sensitive to the glycosilation inhibitor, tunicamycin, indicative of a compromised endoplasmic reticulum (ER) stress response. These results suggest that clade I TGA factors control defence-related secretion events that are required for cell wall-associated defence responses. Analysis of the non-expressor of pathogenesis-related genes 1 (npr1-1) mutant and an tga1-1 tga4-1 npr1-1 triple mutant indicate that clade I TGA factors act substantially independent of NPR1 during plant immune responses. Moreover, mutation of clade I TGA factors also results in developmental changes, including curly leaves and late flowering. Together, these results demonstrate that TGA1 and TGA4 factors play a unique role in mediating both defence responses and developmental processes

Analisis Hidrograf DAS Poso dengan Metode Hidrograf Satuan Sintetis Snyder dan Hidrograf Satuan Sintetis Soil Conversation Service (SCS)

The Poso River is a river located in Poso Regency, Central Sulawesi Province, which has a length of 74.58 km, and watershed area of 1092.810 km2. Energy in the Poso River is used for hydroelectric power plant (PLTA). With the construction of the Poso hydropower plant, maximum flood discharge data is needed for the prevention of Poso hydro power plant safety. In calculating the flood discharge, the method used is a synthetic unit hydrograph. Synthetic unit hydrograph is a graph of the relationship between flow rate (Q) and time (t). In this study, the method used to calculate the designed flood discharge is the Snyder synthetic unit hydrograph method and the Soil Conversation Service (SCS) synthetic unit hydrograph. The aims of this study are to determine the largest flood discharge value and to determine the hydrograph shapes of the two methods. The parameters that will be obtained from both methods are peak time (Tp), base time (Tb) and peak discharge (Qp). From the analysis it can be found that in the Snyder SUH method, the peak time (Tp) is 12.616 hours, the base time (Tb) is 67.276 hours with a peak discharge (Qp) of 21.672 m3sec. Whereas in the SCS SUH method, the peak time (Tp) is 10.954 hours, the base time (Tb) is 57.268 hours with a peak discharge (Qp) of 20.751 m3/sec. The result demonstrates the result that the largest flood discharge has occurred in the Snyder SUH method

Analisis Ketersediaan Air DAS Sausu Untuk Kebutuhan Air Pada D.I. Sausu Bawah, Kabupaten Parigi Moutong

This study aims to grasp and analyze the water availability in Sausu Watershed and the need of water in Lower Sausu Irrigation Scheme. The research begins with data collection and hydro-climatological analysis to determine whether the water is enough or not enough to be used during a hydrological period. To obtain the comparison between the needs and availability of water, a hydro-climatological analysis and calculation of water need are carried out. Methods that used namely the Penman Modification method and the F.J Mock method. Penman modification method is used to calculate monthly evapotranspiration (ETo) by taking into account climatological factors such as air temperature, wind speed, solar radiation and relative humidity. By applying the F.J.Mock method for calculating the water availability, the amount of water flow from the rain, characteristics of the drainage area and evapotranspiration can be calculated. Based on the results of data analysis for Sausu watershed area of 568.64 km², it shows that the average value of water availability in the lower intake for 1 year is app. 30.19 m³/sec with the maximum value of app. 48.149 m3/sec and the minimum is app. 4.134 m3/sec. Whereas the maximum water demand in the Lower Sausu irrigation scheme is app. 1.77 m³/sec with the minimum of 0.04 m3 /sec and the average is app. 0.49 m3/sec. It can be concluded that the water availability in the Sausu River Basin is sufficient to meet the water needs of the Lower Sausu Irrigation Scheme throughout the year, or there is a continuous surplus

Energy Efficiency Opportunities and Savings Potential for Electric Motor and Its Impact on GHG Emissions Reduction

Motors are the single largest users of electric power, consuming over half of all electricity and more than 60% of that used in the industrial sector.  The use of energy-efficient motor technologies offers utilities the possibility of achieving substantial energy savings and reduction of GHG emissions. This paper presents a comprehensive literature review about energy efficiency opportunities and savings potential for electric motor. This paper compiles latest literatures in terms of journal articles, conference proceedings, web materials, reports, books, handbooks on electrical motor energy use, and opportunities for energy efficiency as well as energy savings strategies. Besides, present status of the efficient motor technology, market potential have been presented in this paper. Also, different energy savings strategies such as rewinding, use of variable speed drive (VSD), and capacitor bank to improve the power factor to reduce their energy uses have also been reviewed. Furthermore, cost parameters to carry out economic analysis and payback period for different energy savings strategies have been shown as well.DOI:http://dx.doi.org/10.11591/ijece.v3i4.359