Judul: Diversity of lichens’ three city parks at south jakarta as bioindicators of air pollution
Abstrak: Lumut kerak merupakan organisme yang dapat mengabsorpsi polutan udara namun tidak mampu mengembalikannya kembali ke lingkungan sekitarnya, sehingga polutan udara terakumulasi dan merubah fisiologisnya. Kondisi tersebut menjadikan lumut kerak dapat dijadikan sebagai bioindikator pencemaran udara. Tujuan penelitian ini yaitu untuk mengukur keanekaragaman lumut kerak dan melihat hubungannya dengan karakteristik lingkungan (suhu, kelembapan, SO2, NO2 dan TSP) di tiga taman kota di Jakarta Selatan. Penelitian dilaksanakan pada bulan Maret hingga April 2014. Taman Kota Martha Tiahahu mewakili peruntukan pusat kegiatan sosial ekonomi. Taman Kota Ayodya mewakili peruntukan rekreasi, dan Taman Kota Gandaria Tengah mewakili peruntukan pemukiman. Hasil penelitian menunjukkan bahwa nilai indeks keanekaragaman lumut kerak ketiga taman kota berturut-turut semakin rendah yaitu Martha Tiahahu (1.23), Gandaria Tengah (1.17) dan Ayodya (0.57). Dominasi pohon dengan keliling batang yang besar di Martha Tiahahu diduga menjadi faktor utama tingginya nilai indeks keanekaragaman di taman tersebut. Dari lima karakteristik lingkungan, hanya kelembapan yang memiliki hubungan linier (berbanding lurus) terhadap keanekaragaman lumut kerak., Lichen is an organism that afford to absorb air pollutants but can’t return it back into the surrounding environment, so the air pollutants accumulate and affect physiology. Those conditions make lichens can be used as bioindicators of air pollution. This study’s purpose is to measure the diversity of lichens and see its relationship with environmental characteristics (temperature, humidity, SO2, NO2 and TSP) in three city parks at South Jakarta. The study was conducted in March to April 2014. Martha Tiahahu City Park represents the center of socio-economic activity. Ayodya City Park represents recreation and Gandaria Tengah City Park represents residential designation. The result showed that the value of lichens’ diversity index from the highest value is Martha Tiahahu (1.23), Gandaria Tengah (1.17) and Ayodya (0.57). The large trees dominance at Martha Tiahahu is the major factor of the high value in city park’s diversity index. Moisture is the only one of environment’s character that has a linear relationship (proportional) to the lichens’ diversity.
Keyword: keanekaragaman, kualitas udara, lumut kerak

Judul: The Study of Lichens as Air Quality Bio-indicator in Two Different Locations
Abstrak: Lumut kerak merupakan organisme yang merespon baik adanya perubahan kualitas udara. Penelitian ini bertujuan mengkaji keanekaragaman dan respon lumut kerak di dua lokasi berbeda sebagai bioindikator kualitas udara. Penelitian ini menggunakan data primer dan data sekunder. Pengumpulan data primer dilakukan di Jalan Agatis, Kampus IPB Dramaga pada tanggal 20 Februari – 5 April 2020 dan 23 – 30 Juli 2020. Penelitian ini juga menggunakan hasil data dari penelitian sebelumnya di Jalan Rumah Sakit, Kota Bandung sebagai data pembanding. Data dianalisis menggunakan metode analisis deskriptif analitik. Nilai indeks keanekaragaman lumut kerak pada pohon mahoni di Jalan Agatis (1,83) lebih tinggi daripada di Jalan Rumah Sakit (1,25). Jumlah jenis lumut kerak yang ditemukan di Jalan Agatis sebanyak tujuh jenis dari lima famili, sedangkan di Jalan Rumah Sakit ditemukan lima jenis dari tiga famili. Jenis Dirinaria picta, Lepraria sp., Pyxine cocoes, dan Chrysothrix sp. dapat ditemukan di kedua lokasi. Lumut Kerak di kedua lokasi memiliki respon yang berbeda dalam hal warna, bentuk, keadaan, dan persentase tutupan lumut kerak., Lichen is an organism that responds well to air quality changes. The purpose of the research was to examine the diversity and response of lichens in two different locations as bio-indicator of air quality. This research was sourced on primary and secondary data. Primary data was conducted on Agatis Street, IPB University, on 20 February to 5 April 2020 and 23 to 30 July 2020. This research also used data results from previous research on Rumah Sakit Street, Bandung City as comparative data. The method used to analyze the data was descriptive-analytical. The value of lichens diversity index on mahogany trees on Agatis street (1,83) is higher than in Rumah Sakit street (1,25). The number of lichen's types found on Agatis street as many as seven types of five families, while on Rumah Sakit street found five types of three families. Dirinaria picta, Lepraria sp., Pyxine cocoes, and Chrysothrix sp. can be found in both locations. The lichens in both locations had different responses in terms of color, form, condition, and the percentage of lichens cover.
Keyword: air quality, diversity, substrate

Judul: Construction of Strongly Optimal Binary Linear Code with Minimum Distance 9 and 11
Abstrak: A binary linear code of length n over q F is a subspace of n q F . A code has three parameters that attached to it, namely length, dimension, and minimum distance. A code with length n, dimension k and minimum distance d is often called [n, k, d ]-code. Usually, when two parameters are given, then we want to find a code that has the best value for the last parameter. Based on Gilbert- Varshamov bound, if a [n, k, d ]-code exists and can not be expanded, we call it a strongly optimal code. In this paper, we construct strongly optimal code with minimum distance 9 and 11. In constructing the code, we created a theorem and algorithm based on Gilbert-Varshamov bound before we implement the algorithm to MAPLE programming language. Because of computational limitations, the program can only construct up to k = 10 for d = 9 and k = 12 for d = 11.
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