Analisis Portofolio Optimal Dengan Single Index Model Untuk Meminimumkan Risiko Bagi Investor Di Bursa Efek Indonesia (Studi Pada Saham Indeks Kompas 100 Periode Februari 2010-juli 2014)

Investments can be made in the capital market, capital market instruments which are mostly attractive for investors is stock. Stock provides a return in the form of capital gains and dividends yield, not only noticing the return, investors need to pay attention to the investments risk. Unsystematis risk can be minimized by forming the optimal portfolio using one of the methods that is single index model. Study purpose is to knowing the stocks forming the optimal portfolio, the proportion of funds allocated to each stocks, the level of expectation return and risk.The method used in this research is descriptive research method with a quantitative approach. The samples used were 46 stocks in Kompas 100 Index, which meets the criteria for sampling. The results showed that 12 stocks of forming optimal portfolio, the stocks of which are UNVR, TRAM, MNCN, BHIT, JSMR, BMTR, GJTL, KLBF, AALI, CPIN, AKRA, and ASRI. Stock with highest proportion of funds is TRAM (23,52%), stock with lowest proportion of funds is AALI (0,62%). Portfolio which are formed will give return expectations by 3,05477% and carry the risk for about 0,1228%

Abordagem da história da ciência na construção de um terrário, numa perspetiva de educação para o desenvolvimento sustentável

Mestrado em Ensino de Biologia e Geologia no 3º Ciclo do Ensino Básico e no Ensino SecundárioEm Portugal, avanços têm-se feito notar no que toca à tecnologia, o que leva a que novas aptidões e competências sejam desenvolvidas pelos cidadãos de forma a adaptarem-se à Era da informação. Para tal, é necessário que os alunos saiam já bem preparados das escolas de modo a que as suas aprendizagens atendam a essas mudanças, pois o ensino também implica mudança, evolução e crescimento, não só por parte dos estudantes mas também dos professores, das escolas e de todos os órgãos associados. Desta forma, vários métodos poderão ser implementados nas salas de aulas e um deles é a abordagem à História da Ciência. O presente trabalho investigativo procurou conhecer quais as aprendizagens, comportamentos e atitudes que os alunos desenvolveram ao longo das aulas, dando a conhecer os contributos que a construção de um terrário, através da História da Ciência, pode levar à educação de cidadãos informados, numa perspetiva de Educação para o Desenvolvimento Sustentável. A abordagem foi aplicada a alunos do 8.º ano, na disciplina de Ciências Naturais, utilizando várias técnicas e instrumentos de recolha de dados, nomeadamente, a observação, a análise documental e questionário. O recurso à construção e utilização de um material didático-pedagógico e a abordagem à História da Ciência, permitiram cativar o interesse dos alunos e centraliza-los no processo de ensino e de aprendizagem, no qual o aluno tem o principal papel. Dessa forma, foi possível averiguar como se contextualizam as aprendizagens através da abordagem utilizada, recolher e descrever as perspetivas dos alunos e em desenvolver as aprendizagens, comportamentos e atitudes, numa perspetiva de Educação para o Desenvolvimento Sustentável.In Portugal, advances have been made when it comes to Technology, which leads to new skills and competences to be developed by citizens in order to adapt to the Information age. To this end, it is necessary that students need to be well prepared when they conclude their studies, so that their acquired knowledge could meet these changes, for the teaching also implies changes, evolution and growth, not only by students but also by teachers, schools and all the associated teaching groups. This way, various methods can be implemented in the classroom and one of them is the approach to the History of Science. This research work was aimed to know which learnings, behaviors and attitudes that students developed during the lessons, so that it could be possible to publish the contribution of the construction of a terrarium, based in the History of Science, leading to the education of informed citizens, in a perspective of an Education for Sustainable Development. The approach was applied to 8th grade students, in the discipline of Natural Sciences, using various techniques and data collection instruments, like observation, documental analysis and a questionnaire. Building and using didactic-pedagogic material and applying History of Science knowledge, allowed to captivate the students' interest and it helped centralizing them in the process of teaching and learning, in which the student has the main role. Thus, it was possible to find out how to contextualize the learning through the used approaches, to collect and describe the perspectives of the students and developing the learning subject, behaviors and attitudes on a perspective of Education for the Sustainable Development

Contract negotiation and risk preferences in dual-channel supply chain coordination

<div><p>This study employs profit-sharing contracts to coordinate dual-channel supply chains and examines the selection of profit-sharing parameters and the allocation of extra system profit gained from coordination. We characterise the Pareto-optimal contracts for the two- and three-stage dual-channel supply chains, by developing and maximising system utility function related to risk preferences and negotiating power. Under the optimal profit-sharing parameter in a two-stage supply chain, both members are reluctant to cooperate; however, in a three-stage supply chain, under the optimal two profit-sharing parameters selected by optimising the system utility function, the retailer is always reluctant to cooperate, but the distributor or the supplier may have incentives to deviate from cooperation. In this case, the distributor and the supplier will negotiate again as in a two-stage supply chain so that all three members can benefit from coordination with profit-sharing contracts. Besides acting independently, the distributor, in the process of contract negotiation, may choose to form an alliance with the upstream supplier or the downstream retailer, which means the relationship among the three members involving profit allocation after coordination is quite different from that for a two-stage supply chain and is not necessarily interest-contrary. In the contract negotiation, in any kind of scenario, risk aversion and negotiation power have a significant impact on the selection of optimal profit-sharing parameters and the allocation of extra system profit. One member’s risk aversion or its negotiation power may be advantageous to the other. Mathematical examples are illustrated to clarify the contract negotiation process.</p></div

Alfalfa cropping is superior to cotton and rapeseed cropping in improving the quality and microbial diversity of reclaimed saline soils

Soil salinisation has led to increasing abandonment of farmlands in the arid region of northwest China, and the cultivation of cash crops has become an important way to reuse abandoned farmlands and remediate saline soils. In this study, the effects of cotton (Cot), alfalfa (Alf), and rapeseed (Rap) cropping on the bacterial and fungal communities in saline soil were compared based on high-throughput sequencing. The results showed that soil pH and electrical conductivity (EC) of the Cot, Alf, and Rap groups decreased significantly compared with those of bare land (CK). Especially, soil pH (8.3) and EC (0.93 mS cm-1) of the Alf group decreased the most, and the contents of total nitrogen (TN) and total phosphorus (TP) increased the most, which increased by 250% and 91.4%, respectively compared with those of the CK (p < 0.05). Actinobacteriota and Proteobacteria were the dominant bacterial phyla in the three groups, Ascomycota and Basidiomycota were the dominant fungal phyla. The diversity of soil bacterial and fungal communities in the Alf group was higher than that in the Cot and Rap groups. The results of RDA and PERMANOVA analysis showed that soil pH, EC, C/N ratio, and TN were the main factors affecting soil bacterial and fungal communities in the three groups. In general, Cot, Alf, and Rap cropping all could reduce soil pH and EC and improve soil microbial community structure and diversity, but Alf cropping had the best effects in improving saline soil quality and bacterial and fungal diversity.</p

A solution to the problem of height overcompensation in GNSS-IR corn height measurements: a canopy reflectance calibration model

The global navigation satellite system interferometric reflectometry (GNSS-IR) technique for collecting corn height has the limitation of not accounting for changes in the corn canopy reflector. A model that uses the corn canopy reflection coefficient to account for changes in the canopy’s reflector and the power attenuation of the signal reflected by the soil surface is proposed. This letter proposes a method to solve the overcompensation problem of traditional GNSS-IR vegetation height measurement. Considering the decrease in GNSS signal penetration depth and the upward shift of the actual reflecting surface caused by changes in corn leaf water content (LWC), this letter provides a calibration model for the GNSS-IR corn height measurement. The GNSS signals reflected from the corn canopy were separated using empirical mode decomposition (EMD), and the height measurement was then calibrated using the directed and reflected signal ratios. The results of the experiments show that the model proposed in this letter can effectively improve the accuracy of corn height measurement, and the root mean square error (RMSE) is reduced to 0.17m. Compared with the current study, the model proposed in this study reduces the influence of the actual reflective surface variation of the corn canopy on the height measurement using GNSS-IR.</p

Low-Pressure and Nascent Yields of Thermalized Criegee Intermediate in Ozonolysis of Ethene

The yields of thermalized formaldehyde oxide (CH2OO, the simplest Criegee intermediate) produced from ozonolysis of ethene at low pressures were measured indirectly using cavity ringdown spectroscopy (CRDS) and chemical titration with an excess amount of sulfur dioxide (SO2). The method of monitoring the consumption of SO2 as a scavenger allows better characterization of the CH2OO at low pressure and short residence time. The yield of thermalized CH2OO from ethene ozonolysis was found to decrease with decreasing pressure. The nascent yield of thermalized CH2OO was determined to be 20.1 ± 2.5% by extrapolation of the 7–19 Torr measurements to the zero-pressure limit. Kinetic models enable better evaluation and understanding of the different measurement methods of thermalized Criegee intermediates. The information on the low-pressure yields from this work serves as a benchmark for theoretical calculations and facilitates a better understanding of the alkene ozonolysis reaction mechanisms

Perancangan Dan Implementasi Sistem Kendali Robot Tangan Prensilia

Teknologi robotika pada bidang medis terus berkembang dan penggunaannya semakin luas. Pada tugas akhir ini sistem kendali loop tertutup untuk robot tangan telah dikembangkan dan dievaluasi. Sistem kendali dengan komponen utama mikrokontroler untuk mengendalikan robot tangan IH2 Azzurra mampu bekerja secara real-time. Sistem yang dibuat memiliki antarmuka UART dengan baud rate sebesar 115,2kbps yang dapat menerima masukan dari sensor gerak berupa sarung tangan dan menghasilkan keluaran berupa suatu perintah sebagai masukan robot tangan. Perintah ini mampu mengatur kecepatan motor pada masing-masing jari robot tangan sesuai dengan gerakan tangan melalui sensor gerak. Metode sistem kendali yang digunakan adalah sistem kendali PID diskrit berbasis mikrokontroler ATMEGA8. Performansi dari sistem kendali yang dirancang dapat dilihat secara langsung menggunakan perangkat lunak berbasis PC yang telah dibuat. Selain itu, perangkat lunak PC dapat memperbaharui firmware pada mikrokontroler secara langsung dan parameter-parameter penting pada sistem dapat ditampilkan dalam bentuk grafik, atau disimpan pada media penyimpanan berbasis PC sehingga lebih mudah untuk dianalisa lebih lanjut. Performansi yang dihasilkan sistem cukup baik, dilihat dari nilai error steady state tertinggi sebesar 3,137%, settling time tertinggi sebesar 3,8 detik, overshoot tertinggi sebesar 3,529%, dan RMSE rata-rata tertinggi yang dihasilkan sebesar 0,0595%±0,0119%. Kebutuhan daya pada sistem relatif rendah yakni 111,9mW. Sehingga catu daya baterai li-ion berkapasitas standar dapat digunakan untuk mencatu sistem selama kurang lebih 29,4 jam atau 1,225 hari. Tingkat portabilitas dari sisi kebutuhan daya sudah terpenuhi untuk sistem ini

Benefits of expressive writing in reducing test anxiety: A randomized controlled trial in Chinese samples

<div><p>Purpose</p><p>To explore the effect of expressive writing of positive emotions on test anxiety among senior-high-school students.</p><p>Methods</p><p>The Test Anxiety Scale (TAS) was used to assess the anxiety level of 200 senior-high-school students. Seventy-five students with high anxiety were recruited and divided randomly into experimental and control groups. Each day for 30 days, the experimental group engaged in 20 minutes of expressive writing of positive emotions, while the control group was asked to merely write down their daily events. A second test was given after the month-long experiment to analyze whether there had been a reduction in anxiety among the sample. Quantitative data was obtained from TAS scores. The NVivo10.0 software program was used to examine the frequency of particular word categories used in participants’ writing manuscripts.</p><p>Results</p><p>Senior-high-school students indicated moderate to high test anxiety. There was a significant difference in post-test results (<i>P</i> < 0.001), with the experimental group scoring obviously lower than the control group. The interaction effect of group and gender in the post-test results was non-significant (<i>P</i> > 0.05). Students’ writing manuscripts were mainly encoded on five code categories: cause, anxiety manifestation, positive emotion, insight and evaluation. There was a negative relation between positive emotion, insight codes and test anxiety. There were significant differences in the positive emotion, anxiety manifestation, and insight code categories between the first 10 days’ manuscripts and the last 10 days’ ones.</p><p>Conclusions</p><p>Long-term expressive writing of positive emotions appears to help reduce test anxiety by using insight and positive emotion words for Chinese students. Efficient and effective intervention programs to ease test anxiety can be designed based on this study.</p></div

Reviving the Dead: History and Reactivation of an Extinct L1

<div><p>Although L1 sequences are present in the genomes of all placental mammals and marsupials examined to date, their activity was lost in the megabat family, Pteropodidae, ∼24 million years ago. To examine the characteristics of L1s prior to their extinction, we analyzed the evolutionary history of L1s in the genome of a megabat, <i>Pteropus vampyrus</i>, and found a pattern of periodic L1 expansion and quiescence. In contrast to the well-characterized L1s in human and mouse, megabat genomes have accommodated two or more simultaneously active L1 families throughout their evolutionary history, and major peaks of L1 deposition into the genome always involved multiple families. We compared the consensus sequences of the two major megabat L1 families at the time of their extinction to consensus L1s of a variety of mammalian species. Megabat L1s are comparable to the other mammalian L1s in terms of adenosine content and conserved amino acids in the open reading frames (ORFs). However, the intergenic region (IGR) of the reconstructed element from the more active family is dramatically longer than the IGR of well-characterized human and mouse L1s. We synthesized the reconstructed element from this L1 family and tested the ability of its components to support retrotransposition in a tissue culture assay. Both ORFs are capable of supporting retrotransposition, while the IGR is inhibitory to retrotransposition, especially when combined with either of the reconstructed ORFs. We dissected the inhibitory effect of the IGR by testing truncated and shuffled versions and found that length is a key factor, but not the only one affecting inhibition of retrotransposition. Although the IGR is inhibitory to retrotransposition, this inhibition does not account for the extinction of L1s in megabats. Overall, the evolution of the L1 sequence or the quiescence of L1 is unlikely the reason of L1 extinction.</p></div

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