Judul: Pengaruh Curah Hujan terhadap Gangguan Jaringan PT. Telkom Bogor
Abstrak: Communication using telecommunication may be exposed to disturbance such as connection interruption, disconnection, etc. Climate is considered as one factor affecting these conditions. Too much rainfall may lead to floods that inundate telephone network and finally damage the network. However, the climatic factor has not been taken much into consideration by the telecommunication companies in designing network system. This study aims to assess the relationship between rainfall and level of disturbance of the telecommunication services. This study assessed three types of services, namely PSTN (home telephone), TDSL (internet services), and ISDN (digital services). There were 31 types of disturbances being assessed in the three services. The data of disturbance was collected on daily basis from 2007 to 2008. This study used principal component analysis (PCA) to reduce the number of disturbances into a number of principal components explaining most of the disturbances types. This study found that type of disturbance which frequently occurred was ‘no connecting tone’ (81.4%). Type of telecommunication services being disturbed mostly is PSTN. Types of disturbance can be seen from the factors causing the disturbance and location where disturbance factors occurred. Based on the disturbance factors, corrosion was the most common factor causing the disturbance (38.9%) and based on the location, dropwire was the most common one (35.7%). The analysis suggested that rainfall variability has significant relationship only with certain types of disturbances. At Cibinong, rainfall significantly affected the telecommunication services through its effects on 'network maintenance', 'dashed voice' and 'arrears'. At Dayeuh, rainfall significantly affected the services through its effect on 'SLI disconnection'. At Citeko, rainfall significantly affected the telecommunication services through its effects on 'MMA interruption', 'internet access error', 'browsing error', 'can't be called', 'bell error', 'no connecting tone', 'dashed voice' and 'mussy wiring'. At Jasinga, rainfall significantly didn't affect to any types of network interruption. At Bogor, rainfall significantly affected the telecommunication services through its effects on 'MMA interruption', 'internet access error', 'PCM interruption', 'browsing error', 'can't be called', 'bell error', 'no connecting tone', 'there were connecting tone but no answer', 'dashed voice', and 'mussy wiring'. Based on this study, it is recommended that the PT. Telkom Bogor may need to consider rainfall in designing the wire system particularly outdoor wire. Types of wire for outdoor should be high quality and anti-corrosion. To improve this study, it is recommended to include relative humidity and extreme climate as other climatic factors causing the disturbance.
Keyword: 

Judul: Evaluasi Curah Hujan GSMaP dan TRMM TMPA dengan Curah Hujan Permukaan Wilayah Jakarta – Bogor
Abstrak: Global Satellite Mapping of Precipitation (GSMaP) and Tropical Rainfall Measuring Mission Multi-Satellite Precipitation Analysis (TRMM TMPA) are global measured precipitation projects using satellite combination (blended) technique of infrared sensor and microwave sensor. This research having purpose to evaluate GSMaP and TRMM data with Surface rainfall data in various topographies (beach, level-land, mountainous region, and The whole area) and temporal variation (daily, 10days, and monthly) in Jakarta-Bogor area. The evaluation is done using visual and statistical comparison method (correlation coefficient, MAE, RMSE, and Mann-Whitney Test). The evaluation result of daily and 10days of GSMaP in all area studies showing a pattern didn’t follow the Surface rainfall (r<0.20), while TRMM daily rainfall data in beach area and The whole having r>0.60 and the Mann-Whitney test shows TRMM doesn’t have significant difference with surface rainfall data. 10days TRMM rainfall in all region, except mountainous region, shows TRMM rainfall can follow surface rainfall pattern (r>0.77). Monthly GSMaP data comparison to surface rainfall showing correlation more than 0.60 on beach and land area can be applied, by using correction equation, because GSMaP rainfall data always lower than surface data. The monthly TRMM rainfall data can be applied in all studies area because the pattern is suitable to surface rainfall data (maximum correlation is 0.98). Error identification shows that there is warm rain and high variation on land surface emission especially in mountainous area causing either GSMaP and TRMM cannot follow the surface rainfall data. GSMaP correction equation in beach region, shows the parameter that affect error are surface temperature and specific humidity in 850mb, while at region II, III, and The Whole there is no local parameter which has influence. TRMM correction equation in region III(mountainous area), shows local parameter which has an influence to accurate of this TRMM is surface pressure, wind 850mb, interaction of meridional wind and surface slope, air temperature 850mb, soil humidity in 10-200cm, and skin temperature.
Keyword: 

Judul: Embriogenesis ikan buta (Astyanax fasciatus)
Abstrak: Ikan buta Astyanax fasciatus adalah spesies ikan unik dari famili Characidae yang menempati perairan dalam gua di Wilayah La Cueva Chica-San Luis Potasi-Mexico. Ikan ini memiliki mata yang tereduksi (Blind Cavefish) dan warna kulit merah muda, pucat serta mengkilap.
Keyword: