Metode Penentuan Portofolio Optimal Menggunakan Model Indeks Tunggal Sharpe Saham-Saham LQ45 Tahun 2019

Abstrak--Konstruksi portofolio optimal menjadi fokus perhatian dan semakin menantang bagi manajemen investasi karena pada umumnya investor bermotif untuk memaksimalkan economic value-nya dengan memainkan peran dua variabel utamanya, imbal hasil (return) dan risiko (risk). Single Index Model(SIM) William Sharpe (1963) merupakan model yang sederhana terutama jika dibandingkan dengan model Markowitz (1952), terutama karena pertimbangan jumlah variabel masukannya. Model Markowitz dikatakan memiliki keterbatasan praktis serius; model Sharpe menyederhanakannya (http://www.economicsdiscussion.net/portfolio-management/theories-portfolio-management/sharpe-theory-of-portfolio-management-financial-economics/29763 [r. 07/05/20]).Penelitian ini bermaksud menggambarkan portofolio optimal seperti apa yang dapat dibentuk dari saham-saham LQ45 tahun 2019 menggunakan SIM tersebut. Hasilnya memperlihatkan 27 saham LQ45 terpilih dari 45 saham yang pantas menjadi anggota portofolio optimal dalam pembobotan mulai dari bobot yang tertinggi ke bobot terendah. Dengan tetap menyadari sepenuhnya bahwa SIM hanya menggunakan indeks (pasar) sebagai satu-satunya faktor pembentuk risiko berinvestasi,penerapan model ini memberikan pembelajaran yang amat berharga justru karena kesederhanannya sehingga mampu memberikan gambaran yang jelas dan dengan demikian tetap perlu dipelajari sebagai pengetahuan dasar dalam Mengelola Portofolio/ Investasi. Kata kunci: Sharpe’s Single Index Model, Portfolio Analysis, Optimal Portfolio Con-struction, Risk Characteristic Line. Abstract--Optimal portfolio construction is the focus of attention and is increasingly challenging for investment management because in general investors are motivated to maximize their economic value by playing the role of two main variable, return and risk. William Sharpe’s (1963) Single Index Model (SIM) is a simple model especially when compared to the Markowitz model (1952), mainly because of the consideration of the number of input variables. The Markowitz model is said to have serious practical limitations; the Sharpe model simplifies it (http://www.economicsdiscussion.net/portfolio-management/ theories-portfolio-management/sharpe-theory-of-portfolio-management-financial-econo-mics/29763 [r. 07/05/20]). This study intends to describe what optimal portfolio can be formed from LQ45 shares in 2019 using the SIM. The results show 27 selected LQ45 shares from 45 shares that deserve to be members of the optimal portfolio in weighting starting form the highest weight to the lowest weight. By being fully aware that SIM uses only the index (market) as the sole factor for investment risk, the application of this model provides valuable learning precisely because of its simplicity so as to provides a clear picture and thus need to be learned as basic knowledge in Managing Portfolio/ Investments. Keywords: Sharpe’s Single Index Model, Portfolio Analysis, Optimal Portfolio Con-struction, Risk Characteristic Line.

Safe Concentration of Benzene Exposure in Work Environment at Motor Workshop

Benzene is a colorless liquid that can evaporate rapidly in air and slightly dissolved in water. Exposure of benzene to the body has a very adverse impact on health. The aims of this research were to know benzene risk characteristic or RQ, and safe concentration of benzene exposure in a workshop environment. This research was observational, cross-sectional design with a population of 7 workers of the motor industry in Surabaya. The benzene exposure in the workplace was measured by Gas Chromatography-Flame Ionization Detector (GC-FID). Data analysis was done by using quantitative data. Maximum benzene intake received by workers was 0.1837 mg/kg/day. RQ on average workers more than 1 (> 1), with the highest RQ of 22.673. The highest safe concentration of workers was 3.9 mg/m3 and the lowest safe concentration was 0.4 mg/m3. The concentration of benzene exposure in the motor industry showed was above the threshold limit. According to the regulation of Manpower and Transmigration Ministry No 13 the year 2011, RQ for benzene showed a high-risk impact for workers, the smallest safe concentration for the worker was 0.4 mg/m3.

Studi Perbandingan Nilai Value at Risk Antara Saham Berbasis Syariah Dengan Saham Non Syariah Periode 2010-2012

This study aimed to empirically compare the risk between sharia and non-sharia based stock investment. The Sharia stocks are refereed to stocks that issued by companies listed in LQ-45, whereas the non-sharia stocks are defined as stocks that are issued by companies listed in Jakarta Indonesia Index (JII) between 2011 and 2012. In total, there were 25 companies listed in LQ-45 and 15 companies listed in JII which were involved in this study. This study used GARCH model to estimate the risk of every individual stock. The result showed that there was a difference in risk between sharia and non-sharia based stock. This study also documented that non-Sharia based stocks were more risky than Sharia-based stodcks. Finally, this study provides information on risk characteristic in Indonesia Capital Market.

Health Risk Characteristic Due to Air Pollution Exposure in Shoe Soles Workers (around Bubutan Road in Surabaya city)

Risk characterization is end of the risk assessment process. Toxin agent can enter the human body by inhalation process, skin (dermis) and digestion process. The objectives of this research is to determine risk characterization of exposure to air pollutans on the health of sole services worker. This study was an observational study with cross sectional approach. 25 people of this sampel study were the total population. Independent variabels were age, weight, lenght of work in this sector, lenght of exposure time, number of working days. Dependent variabels were the concentration of CO, SO2 and NO2. Data were analyzed descriptively and the result of the data would be narrated and shown on the frequency table. Result the exposure assessment of carbon monoxide parameter on sole services workers were gotten the highest intake value was 0.2028 mg/kg/day and the lowest value was 0.0085 mg/kg/day, sulfur dioxide parameter on sole services worker were gotten the highest intake value was 0.0004028 mg/kg/day and the lowest value was 0.0000169 mg/kg/day, nitrogen dioxide parameter on sole services worker were gotten the highest intake value was 0.01238 mg/kg/day and the lowest value was 0.00051 mg/kg/day. Based on the results of the research, it can be concluded that RQ < 1 showed that air quality is still safe. But, in fact is still founded the lamentation of the health disruption and the uncomfort air condition arround the survey area. Research of Refferences of Concentration (RfC) will be needed, especially for CO, SO2 and NO2 parameter fi t of the characteristic of Indonesian people and especially informal sector worker in Surabaya.Keywords: Risk Quotient, Exposure of CO, SO2 and NO2, Workers