Judul: Biaya Eksternal dan Willingness to Accept Masyarakat Akibat Eksternalitas Negatif Pabrik Gula Rafinasi Kabupaten Lampung Selatan
Abstrak: The increase in population effects the demand of sugar. This has led to positive and negative externalities. This research uses qualitative descriptive analysi, loss of earnings method, Contingent Valuation Method (CVM), and multiple linear regression. The example research is purposive sampling. The result shows that the negative externatilies that most imposed on society is degradation of groundwater’s quantity and quality along with degradation of river water quality. This negative externalities caused the society to spend IDR9,176,115,390 of external costs every month. Average WTA value on respondent that owned dried and contaminated well is IDR256,757 per month per patriarch and IDR341,538 per month per patriarch for respondent that owned rice field near the river and cattle which consumed the river water. Several factors that influence respondent’s WTA value for dried and contaminated well: job as farmer, job as breeder, other job, amount of loss, age, income, and water taste, whereas for respondent that owned rice field near the river and cattle: dependent amount, long in stay, job as farmer, job as breeder, amount of loss, age, income, dan water smell.
Keyword: willingness to accept, refined sugar factory, negative externalities, external cost, estimation

Judul: Estimasi Biaya Eksternal dan Willingness to Accept Masyarakat Akibat Pencemaran di Sekitar Kawasan Pabrik Gula Cepiring, Kendal
Abstrak: The activities of economy, such as production and consumption may reduce the level of environmental quality. An industrial activity is one of the economic activities that has effects not only in economic and social aspect but also influences the physical change of environmental quality. A variety of measures and procedures can be used to improve or maintain environmental quality. Therefore, the study of the estimation of both external cost and people’s willingness to accept (WTA) compensation, the effects toward environment caused by industrial activities is needed for doing further arrangements about environmental charges or taxes to achieve sustainable development. The objective of this study is to identify the society who living in the industry area, to estimate both the external cost and WTA value caused by industrial activities, and to identify the factors that influence WTA value. This paper presents a survey which explores the descriptive analysis, valuation of environmental economics, and application of contingent valuation method (CVM). The observations and interviews were conducted to society who live in sugar industry area, Cepiring-Kendal taken by purposive sampling method. The result shows that the external cost of each household per month is 64.721 IDR, the external cost of society of RW 04 Cepiring is 229.845.336 IDR, while in agricultural sector is 314.720.000 IDR per year. Compared to the external cost of each household, the average of mean values of household’s WTA per month is higher, which is 440.132 IDR. There are five factors that influence WTA value significantly such as education level, houses from industry area, quality of noise, economic losses caused by water pollution, and zero-effort to replace the environmental quality.
Keyword: 

Judul: Penggunaan Teorema Homeomorphy 2-Manifold dan Teorema Euler Poincare pada Torus 𝑇�� dan Simplicial Complex 𝐾��
Abstrak: Two dimensional topological spaces are said to be homeomorphic if they have the same topological invariant, where one of topological invariant used is an Euler characteristic. Homeomorphy 2-Manifold’s Theorem and Euler Poincare’s Theorem are used to distinguish two topological spaces. Homeomorphy 2-Manifold’s Theorem uses Euler characteristic to identify two dimensional topological spaces. Euler Poincare’s Theorem is an alternative way to find Euler characteristic with Betti number, which is topological invariant as well. The objective of this paper is to investigate the homeomorphism of torus 𝑇����� and simplicial complex 𝐾�����. Topological space torus and simplicial complex 𝐾����� have the same Euler characteristic, which is two. Based on Homeomorphy 2-Manifold’s Theorem topological space torus 𝑇����� and simplicial complex 𝐾����� is homeomorphic.
Keyword: simplicial, torus, Euler, homeomorphism, topology