Judul: Kesuburan alami dan homogenitas bahan induk tanah-tanah di Daerah Karangsambung, Kebumen, Jawa Tengah
Abstrak: Karangsarnbung region, Kebumen, Central Java was a region which formed by geological formation resulted interaction between Australia's Indian Ocean plates with Eurasia continental plates and has various rocks from several ages and forming process. The rocks were recording of earth process which will result different soil characteristic. This research was aimed to study natural fertility and homogeneity of soil parent materials which was developed fiom several rocks. Research was done in Natural Geological Laboratory Karangsarnbung, Kebumen. Soil samples were collected in 6 profiles. PI from diabas, P2 from phylite, P3 &om chert, P4 fi-om marble, P5 from basalt, and P6 from shale This research was done through analysis of clay fraction use DTAJTG and FTIIRS to determine type of clay mineral and analysis of soil parent material
Keyword: 

Judul: Evaluation of Weathering Stage, Soil Development, and Soil Classification at Karangsambung Formation and Melange Lok Ulo complex in Karangsambung, Kebumen, Central Java. Supervised
Abstrak: Geographically Indonesia is a country that is influenced by Hindia Australia, Eurasia, and Pacific plates interaction. One of the evidence of interaction can be seen in Karangsambung, Kebumen, Jawa Tengah. According to Sukendar Asikin (1974), stratigraphy of Karangsambung is Melange Lok Ulo complex, Totogan-Karangsambung formation, Waturondo formation, and Panosogan formation. This research was aimed to study the relation between geologic formation/soil parent material as one of land component with weathering stage, soil development and its soil classification by Soil Taxonomy System. The research was done with soil morphology description of six soil profiles that located in Karangsambung formation (P1 developed on diabas and P6 develop on Shale) and Melange Lok Ulo complex (P2 developed on phylite, P3 developed on chert, P4 developed on marble, and P5 developed on basalt). Besides that, soil sampling, laboratory analysis, evaluation of weathering stage by mineralogical, chemical, and physical methods, and soil classification by Soil Taxonomy were also conducted. Based on the evaluation of weathering stage from mineralogical, chemical, and physical methods, it was obtained that the physical and chemical estimation method is relative analogously, whereas mineralogical method is not. The order of weathering stage sequencly is P4>P1>P5>P3>P2>P6. These soil profiles are categorized as developed profiles. The order of soil development stage was determined by horizon completeness and effective depth of soil. The soil development sequence is P4>P1>P3>P2>P6>P5. Using Soil Taxonomy (USDA, 2006), the soil formed at Karangsambung formation is classified as Typic Dystrudepts, whereas the soil formed at Melange Lok Ulo Complex as Fluventic Dystrudepts and Typic Dystrudepts. Based on this soil classification system, geologic formation has indirect correlation with soil’s name family category, likewise with weathering stage and soil development.
Keyword: 

Judul: Truncated Stop Loss as a Optimal Solution of Reinsurance Agreement in One-Period Model
Abstrak: Reinsurance is one of risk management efforts of an insurance company, which is called the cedent. Similar with insurance, reinsurance constitutes the cedent to pay the premium. We consider one-period reinsurance model and derive a rule which minimizes the ruin probability of the cedent for a fixed reinsurance premium. Therefore, it is needed to construct an optimal reinsurance agreement for the cedent. The premium is calculated according to four different principles, i.e. economic, generalized zero-utility, Esscher, and mean-variance principles. Stop loss is a reinsurance contract which protect the insurance company for losses that exceed a certain amount. The result of this research shows that a truncated stop loss is an optimal agreement in the class of all reinsurance contracts with various premiums calculated using above mentioned principles.
Keyword: