Fidelity metrics for virtual environment simulations based on spatial memory awareness states

This paper describes a methodology based on human judgments of memory awareness states for assessing the simulation fidelity of a virtual environment (VE) in relation to its real scene counterpart. To demonstrate the distinction between task performance-based approaches and additional human evaluation of cognitive awareness states, a photorealistic VE was created. Resulting scenes displayed on a headmounted display (HMD) with or without head tracking and desktop monitor were then compared to the real-world task situation they represented, investigating spatial memory after exposure. Participants described how they completed their spatial recollections by selecting one of four choices of awareness states after retrieval in an initial test and a retention test a week after exposure to the environment. These reflected the level of visual mental imagery involved during retrieval, the familiarity of the recollection and also included guesses, even if informed. Experimental results revealed variations in the distribution of participants’ awareness states across conditions while, in certain cases, task performance failed to reveal any. Experimental conditions that incorporated head tracking were not associated with visually induced recollections. Generally, simulation of task performance does not necessarily lead to simulation of the awareness states involved when completing a memory task. The general premise of this research focuses on how tasks are achieved, rather than only on what is achieved. The extent to which judgments of human memory recall, memory awareness states, and presence in the physical and VE are similar provides a fidelity metric of the simulation in question

Efektivitas Penerapan Model Pembelajaran Student Fasilitator And Explaining Menggunakan Media Concept Map terhadap Peningkatan Pemahaman Konsep

Penelitian ini bertujuan (1) Untuk mengetahui gambaran peningkatan pemahaman konsep siswa kelasX SMA Negeri 1 Walenrang yang diajar menggunakan model pembelajaran Student Fasilitator andExplaining (2) Untuk mengetahui gambaran peningkatan pemahaman konsep siswa kelas X SMANegeri 1 Walenrang yang diajar tanpa menggunakan model student fasilitator and explaining (3)Untuk mengetahui model pembelajaran Student Fasilitator and Explaining efektif untukmeningkatkan pemahaman konsep fisika siswa dari pada siswa yang tidak diajar dengan modelpembelajaran Student Fasilitator and Explaining kelas X SMA Negeri 1 Walenrang. Penelitian inimerupakan jenis penelitian Quasi Experimental Design dengan menggunakan desain penelitian pretestposttestcontrol group design. Teknik analisis yang digunakan adalah analisis statistik deskriptif dananalisis statistik inferensial. Berdasarkan hasil analisis statistik inferensial diperoleh Dhitung = 0,56 , dapat disimpulkan bahwapenerapan Model pembelajaran Student Fasilitator and Explaining dengan Menggunakan MediaConcept Map efektif untuk meningkatkan pemahaman konsep fisika siswa daripada siswa yang tidakdiajar dengan model pembelajaran Student Fasilitator and Explaining dengan Menggunakan MediaConcept Siswa Kelas X SMAN 1 Walenran

Le comportement d'un système hydrologique en climat méditerranéen par l'analyse corrélatoire et spectrale des débits et des pluies. Cas de trois sous bassins sud-méditerranéens : (oued Sebdou, Moulah et Isser - Tafna - NW Algérie)

Les analyses corrélatoire et spectrale des chroniques de la pluie (entrée) et de débits (sortie) journaliers enregistrés au niveau des trois bassins sud méditerranéens Sebdou, Mouilah et Isser durant un seul cycle hydrologique nous ont permis d’obtenir des informations sur le fonctionnement de ces systèmes hydrologiques. Bien que la structure du signal « pluie » semble présenter les mêmes caractéristiques pour les trois bassins, le signal de sortie « débit » indique que l’oued Sebdou réagit différemment par rapport aux oueds Mouilah et Isser.The aim of this work was to show that correlation and spectral analyses can be used to understand the functioning of hydrological systems. Accordingly, a study was carried out on three southern Mediterranean basins: Sebdou; Mouilah and Isser; located in the north western of Algeria. (Figure 1). Correlation and spectral analyses of daily rainfall and discharge rates for one hydrological cycle were carried out.Simple analysisSimple analysis of rainfall showed that the correlograms (Figure 2) decreased rapidly for the three basins, reaching a value of 0.2 within 1-2 days. This result indicated that rainfall was a quasi-random phenomenon. The variance density spectrum (Figure 3) showed that the rainfall distribution was not monotonous and presented a “Leigh” signal structure.The simple analysis of discharge rates indicated that the Sebdou system was different. The correlogram (Figure 4a) decreased quickly, characterising independent events without memory and with non-significant amounts of water. However, the Mouilah and Isser correlograms (Figure 4 b,c) decreased slowly. They represent important memory effects with regulation of significant amounts of water. The spectral band (Figure 5) confirmed that the Sebdou system did not modify the input information. The regulation time was about 5 d for Sebdou, 21 and 43 d respectively for Mouilah and Isser.Cross analysisThe correlograms (Figure 6) show that the Mouilah and Isser rivers have a great buffering ability. The Sebdou River was characterised by a composite response of the surface flow and an important groundwater flow. The amplitude function (Figure 7) indicated that the Sebdou system had good inertia. The lag time (Figure 8) was 9, 2 and 5 days respectively for the Sebdou, Mouilah and Isser rivers. The amplification and attenuation of the input signal (Figure 10) show that the Sebdou basin is the most karstified system. The non-linearity of the relationship between rainfall and discharge was expressed by the coherence coefficient (Figure 9), which was lower than 1

Incidences de pluies exceptionnelles sur un aquifère libre côtier en zone semi-aride (Chaouia, Maroc)

Les eaux souterraines qui représentent les seules ressources en eau de la Chaouia côtière, sont très minéralisées : intrusion marine, évaporation et recyclage des eaux d'irrigation chargées en sels. L'évolution spatio-temporelle piézométrique et hydrochimique de cet aquifère a été observée sur 179 puits, de 1991 à 1998 qui inclue une période exceptionnellement pluvieuse. Une comparaison par rapport à l'état de la nappe en 1971, date du début de l'exploitation des eaux souterraines, a été faite. Les suivis ont montré qu'à la suite des pluies importantes de 1996 (943 mm), un rehaussement important du niveau de la nappe et des dilutions plus ou moins retardées de tous les sels en solution dans l'eau, sont mesurés dans tous les puits. En effet, la nappe qui a accusé des baisses de 10 à 20 m entre 1971 et 1995, remonte en 1996 de 4,5 à 12,5 m en moyenne surtout au centre et à l'amont de la plaine. Quant à la qualité des eaux qui s'était dégradée, elle a connu des améliorations importantes avec des variations de 0,5 à plus de 4 ms/cm au niveau de la conductivité électrique. Ces faits montrent une grande sensibilité de la nappe aux apports par les pluies qui constituent sa principale alimentation.A study of regional pollution in the coastal aquifer system between Oum-er-Rbia River and Bir Jdid (Coastal Moroccan Meseta, Morocco) was based on data gathered from 1995 to 1998. The study improved the hydrogeological and hydrochemical understanding of the aquifers. The study examined the effects of significant rains on the quantity and quality of coastal groundwater. These waters exhibited high sensitivity to the rain input.Measurements undertaken since 1991 on 179 wells in the study area reveal that the groundwaters are highly mineralized - conductivity reaches more than 10 mS/cm, depending on season and well location. These results also show high chloride concentrations (more than 3500 mg/l), sodium concentrations frequently in the 500 - 1000 mg/l range and nitrates between 150 and 250 mg/l.In coastal Chaouia, these high concentrations of dissolved mineral salts aggravate the problem of supplying quality water to the rural population for drinking or even market-gardening irrigation purposes. The area is characterized by increased irrigated surfaces (more than 16000 hectares with 4125 m3 /s) and a demographic rise that has triggered the chaotic boring of more than 2000 wells into a heterogeneous aquifer sensitive to salinity. Possible sources of this high salinity include :Seawater intrusion into coastal aquifer sectors (mainly into a two-kilometre strip of coastline). The degree and the length of the marine intrusion were exacerbated by intensive pumping for irrigation needs, particularly during the dry season. Other factors such as coastal aquifer permeability, saturation zone thickness and basement depth also affect the degree and length of the marine intrusion. Seawater pollution is more marked in the southwestern coastal area.Reuse of irrigation saline waters, especially as groundwater circulates in the coastal and eastern sectors deep in the soil (to depths of 10 m).Several important factors have been highlighted concerning the origin of the chemical elements in solution and the mechanism of hydrochemical distribution: evaporation, lithology of tapped aquifers, water table depth, distance of wells from the coast, type of soil, use of fertilizers, frequency of pumping operations, and rainfall, among others.A regular network of 179 wells was monitored and surveyed in this study. Spatial and temporal changes in the water table and in the hydrochemistry of the aquifer were monitored between 1991 and 1998, a span which included an exceptionally rainy period (1996). Data are compared with those from 1971, the year groundwater exploitation began.The studied region is characterized by a semi-arid climate, mean annual rainfall of 391 mm (between 1977 and 1998), mean temperature of 17.8 °C, and mean rainfall input of 142 mm. In the dry season, high temperature combined with low rainfall and intensive pumping operations give rise to salinization of shallow groundwater. Groundwater in the area of study circulates in two principal hydrogeological matrices :1. Sandy-calcareous Plio-Quaternary and paleozoic strata in costal sectors and the eastern part located between Tnine Chtouka and Bir Jdid. These hydrogeological strata are characterized by significant porosity and permeability and are exploited at a shallow depth, generally less than 14 m, under sandy-clayed soil.2. A Cretaceous aquifer in marly limestone located between Oum-er-Rbia River and Tnine Chtouka. This aquifer is characterized by a low permeability and a water table generally exceeding 24 m in depth.Monitoring showed that after the heavy rains of 1996 (943 mm, with infiltration of 142 mm), the water table rose markedly in all study wells and a lagged dilution (3 to 6 months) was noted for all mineral salts dissolved in water. In fact, the water table, which had dropped between 1971 and 1995 (10 m in the costal sectors and 20 m in the others parts of the studied region), rose by an average 4.5 to 12.5 m in the central and up-gradient parts of the plain. Several factors were at work between 1971 and 1995: decreased pumping times (about 15 minutes) combined with sharp decreases in the thickness of the saturated zone; appearance of a closed piezometric level in the western region between Oum-er-Rbia River and Tnine Chtouka; and desiccation of 59 wells. With the aid of a polynomial model, annual level evolution of the five coastal test piezometers showed correlation factors of 0.76 to 0.93 respectively for years 1996 and 1997. Other quantitative effects of exceptional rains on groundwater identified include: increased pumping time (up from less than 15 minutes prior to the heavy rains of 1996); increased saturated zone thickness; rises in the water-table surpassing former sea-level heights in certain wells ; general advancement of the piezometric levels towards the coastline; and increased aquifer thickness stemming from longer pumping times.In terms of quality, groundwater showed gradually increasing salinity (by a factor of 2) between 1971 and 1995 and significant improvements after the rains of 1996. Between 1971 and 1995, increased mineralization was observed mainly in coastal and eastern parts of the aquifer between Tnine Chtouka and Bir Jdid. Conductivity of the waters in some coastal wells increased from 5 mS/cm to more than 10 mS/cm. After the exceptional rains of 1996, differences ranging from 0.5 to more than 4 mS/cm were observed in 71 % of the 179 wells analysed. Over the same period, chloride concentrations decreased by average values ranging from 150 to 500 mg/l (higher decreases surpassed 1000 mg/l). By contrast, spatial distributions of conductivity and of the main mineral salts remained unchanged and coastal and eastern groundwaters were still the most vulnerable to high salinity.The quantitative and qualitative effects of heavy rain point to the high sensitivity of these groundwaters to rain input, which is the principal recharge source of the studied aquifer

Pengembangan Instrumen Tes Diagnostik Pilihan Ganda Dua Tingkat Untuk Mengidentifikasi Pemahaman Konsep Matematika

Penelitian ini bertujuan menghasilkan sebuah instrumen tes diagnostik untuk mengidentifikasi tingkat pemahaman konsep matematika siswa yang berbentuk pilihan ganda dua tingkat. Penelitian ini merupakan penelitian Research & Development (R & D) dengan menggunakan model pengembangan Tessmer yang dikenal dengan tipe formatif evaluation. Pengembangan Tessmer terdiri dari 4 tahap yaitu preliminary, self evaluation, tahap prototyping (expert reviews, one-to-one dan small group) dan field test. Angket respon siswa pada instrumen tes diagnostik pilihan ganda dua tingkat memenuhi kriteria tercapai dan tidak ada perbaikan/revisi terhadap instrumen tes yang akan dikembangkan karena lebih dari 50% siswa yang memberikan respon positif. Dari hasil angket respon siswa dapat diketahui bahwa produk instrumen tes diagnostik ini dapat dikatakan praktis untuk digunakan. Hasil data tes diagnostik pilihan ganda dua tingkat untuk mengidentifikasi pemahaman konsep siswa, dapat diketahui bahwa jumlah siswa yang termasuk dalam kategori paham konsep 58,95%, persentase siswa yang mengalami miskonsepsi sebesar 12,63% dan persentase siswa yang tidak paham konsep sebesar 28,25%. Berdasarkan hasil pekerjaan siswa dalam menjawab tes diagnostik pilihan ganda dua tingkat dapat dikatakan bahwa produk instrumen tes ini cukup efektif dalam mengidentifikasi tingkat pemahaman konsep matematika siswa

Pelatihan E-learning Edlink Sebagai Media Pembelajaran Di SMK Negeri 2 Gorontalo Utara

Tujuan dari pengabdian ini adalah untuk menambah pengetahuan dan wawasan tentang inovasi pembelajaran berbasisE-learning bagi siswa-siswi SMK Negeri 2 Gorontalo Utara dengan melalui kegiatan pelatihan penggunaan Edlink. Kegiatan ini dihadiri oleh siswa, guru pamong, dengan metode implementasi pengabdian menggunakan metodeceramah, pertanyaan dan jawaban, serta simulasi. Hasil pendampingan ini menunjukkan bahwa media pembelajaransangat penting bagi pendididikan. Dalam konteks pendidikan, e-learning dapat digunakan dalam berbagai tingkatpendidikan, mulai dari pendidikan anak usia dini hingga pendidikan tinggi dan pendidikan pendidikan non-formal. E-learning dapat menjadi alternatif bagi siswa yang kesulitan dalam menghadiri kelas reguler karena jarak,keterbatasanfisik, atau alasan lainnya. E-learning juga dapat memungkinkan siswa untuk memperoleh akses ke berbagai materipembelajaran dan sumber daya yang mungkin tidak tersedia di lingkungan pembelajaran tradisional. Pendampinganberfokus pada kesulitan siswa dalam melakukan pengelolaan kelas dengan Edlink, harapannya siswa mampumenyesuaikan dan memiliki pengetahuan baru. Ada pemberian materi secara langsung untuk tim pengabdian kepadasiswa dengan metode ceramah, yang diikuti dnegan sesi tanya jawab oleh peserta dalam sesi tnya jawab sehinggapelaksanaan kegiatan pengabdian kepada masyarakat ini dalam bentuk pelatihan penggunaan platform aplikasi E-learning Edlink. Pemberian metode ceramah ini dimaksudkan untuk menyamakan persepsi antara tim mengajar di sekolah  dengan peserta pelatihan  terkait  Edlink. Luaran yang dicapai dari kegiatan pengabdian keoada masyarakat ini yaitu: peserta pelatihan yang berasal dari siswa SMK Negeri 2 Gorontalo Utara telah memiliki pengetahuan dan wawasan tentang cara mengembangkan serta menggunakan aplikasi E-learning Edlink, memiliki e-learning sendiri agar dapat mendukung proses pembelajaran agar lebih menarik bagi siswa

PENGEMBANGAN INSTRUMEN TES DIAGNOSTIK PILIHAN GANDA DUA TINGKAT UNTUK MENGIDENTIFIKASI PEMAHAMAN KONSEP MATEMATIKA

Abstrak:Penelitian ini bertujuan menghasilkan sebuah instrumen tes diagnostik untuk mengidentifikasi tingkat pemahaman konsep matematika siswa yang berbentuk pilihan ganda dua tingkat. Penelitian ini merupakan penelitian Research & Development (R & D) dengan menggunakan model pengembangan Tessmer yang dikenal dengan tipe formatif evaluation. Pengembangan Tessmer terdiri dari 4 tahap yaitu preliminary, self evaluation, tahap prototyping (expert reviews, one-to-one dan small group) dan field test.Angket respon siswa pada instrumen tes diagnostik pilihan ganda dua tingkat memenuhi kriteria tercapai dan tidak ada perbaikan/revisi terhadap instrumen tes yang akan dikembangkan karena lebih dari 50% siswa yang memberikan respon positif. Dari hasil angket respon siswa dapat diketahui bahwa produk instrumen tes diagnostik ini dapat dikatakan praktis untuk digunakan. Hasil data tes diagnostik pilihan ganda dua tingkat untuk mengidentifikasi pemahaman konsep siswa, dapat diketahui bahwa jumlah siswa yang termasuk dalam kategori paham konsep 58,95%, persentase siswa yang mengalami miskonsepsi sebesar 12,63% dan persentase siswa yang tidak paham konsep sebesar 28,25%. Berdasarkan hasil pekerjaan siswa dalam menjawab tes diagnostik pilihan ganda dua tingkat dapat dikatakan bahwa produk instrumen tes ini cukup efektif dalam mengidentifikasi tingkat pemahaman konsep matematika siswa.Abstract:The study is aimed at producing a diagnostic test instrument to identify the level of understanding of mathematical concepts of students in the form of two-level multiple choice. This research is a Research & Development (R & D) by using Tessmer development model known as formative type evaluation. The development of Tessmer consists of four stages: introduction, self-evaluation, prototyping (expert review, one-to-one and small group) and field testing. Questionnaire responses of students on the two-level multiple choice diagnostic test instrument meet the achieved criteria and no improvement/revision of the test instrument to be developed as more than 50% of the students responded positively. From the questionnaire results of students’ response, it can be identified that the product of diagnostic test instrument can be said to be practical to use. The results of the two-level multiple choice diagnostic test instrument data to identify students' concept of understanding can be observed that the students who understand the concept, those who experienced misconceptions, and who do not understand the concept are 58.95%, 12.63%, and 28.25% respectively. Based on the results of the students’ work in answering the two-level multiple choice diagnostic test, it can be said that the test instrument product is quite effective in identifying the level of understanding of students' mathematical concepts

A common mechanism for efficient N 2 O reduction in diverse isolates of nodule‐forming bradyrhizobia

Bradyrhizobia are abundant soil bacteria, which can form nitrogen‐fixing symbioses with leguminous plants, including important crops such as soybean, cowpea and peanut. Many bradyrhizobia can denitrify, but studies have hitherto focused on a few model organisms. We screened 39 diverse Bradyrhizobium strains, isolated from legume nodules. Half of them were unable to reduce N2O, making them sources of this greenhouse gas. Most others could denitrify NO3‐ to N2. Time‐resolved gas kinetics and transcription analyses during transition to anaerobic respiration revealed a common regulation of nirK, norCB and nosZ (encoding NO2‐, NO and N2O reductases), and differing regulation of napAB (encoding periplasmic NO3‐ reductase). A prominent feature in all N2‐producing strains was a virtually complete hampering of NO3‐ reduction in presence of N2O. In‐depth analyses suggest that this was due to a competition between electron transport pathways, strongly favouring N2O over NO3‐ reduction. In a natural context, bacteria with this feature would preferentially reduce available N2O, produced by themselves or other soil bacteria, making them powerful sinks for this greenhouse gas. One way to augment such populations in agricultural soils is to develop inoculants for legume crops with dual capabilities of efficient N2‐fixation and efficient N2O reduction