Judul: Algoritma untuk Dekomposisi Digraf Terboboti dengan Aplikasi Analisis Siklus Kehidupan Dipsacus sylvestris
Abstrak: Life cycle analysis is often carried out by ecologists. Life cycle can be described by digraph (directed graph), which consists of nodes as the stages of life cycle and the edges as the contribution of one life stage to another life stage. Further, the digraph was analyzed using algorithmic graph theory. This approach is done by decomposing weighted digraph by determining the cycle and then remove the edge with the smallest weight in the cycle. This digraph consist of two parts. The first part contains cycles that do not contain contradictory directions. The second contains no cycle. This algorithm ensures that the resulting cycle does not lead the contrary, when applied to the analysis of the life cycle.
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Judul: Pelabelan Komposit Pada Tree, Cycle, dan Graf Tangga.
Abstrak: Suatu Graf G dapat dikatakan memiliki pelabelan komposit jika graf tersebut memenuhi fungsi bijektif f:(V(G)UE(G))→{1,2,3,…,m+n} dan gcd⁡(f(uv),f(vw))≠1 dengan n adalah banyaknya verteks, m banyaknya sisi, dan u,v,w∈V(G). Graf yang memiliki pelabelan komposit disebut graf komposit. Dalam karya ilmiah ini, akan ditunjukan bahwa tree, cycle, dan graf tangga memiliki pelabelan komposit., A Graph G=(V(G),E(G)) can be said to have composite labeling if the graph fulfills the function of f:(V(G)UE(G))→{1,2,3,…,m+n} and gcd⁡(f(uv),f(vw))≠1 with order n, size m, and u,v,w∈V(G). A graph that admits composite labelling is know as a composite graph. This papper shows that the tree, cycle, and the ladder graph have composite labeling.
Keyword: Tree, cycle, Ladder graph, Composite Labeling

Judul: Integration of Islamic Stock Markets of OIC Countries Before and During the Russia-Ukraine War Crisis
Abstrak: Pasar saham yang terintegrasi memberikan dampak negatif seperti percepatan co-movement (pergerakan bersama) yang rentan terhadap guncangan ekonomi, maupun krisis pasar global ke pasar domestik. Salah satu krisis yang terjadi pada tahun 2022 adalah perang Rusia-Ukraina yang berdampak pada pasar saham, termasuk pada saham syariah yang dipercaya lebih tahan terhadap guncangan krisis global. Penelitian ini bertujuan untuk meneliti perkembangan, integrasi dan respon lima pasar saham syariah negara OKI pada perang Rusia-Ukraina. Metode yang digunakan adalah VAR/VECM pada indeks DJIMMT25, SPSADS, SPSUAEDS, JII, DJIMT, SPBMIR, dan SPBMIU. Hasil penelitian menunjukkan pergerakan yang sama pada pasar saham UAE dan Arab Saudi, sedangkan Turki mengalami tren positif selama perang. Pasar saham syariah negara OKI selama periode perang Rusia-Ukraina terkointegrasi, sementara pasar saham Malaysia memengaruhi pasar saham syariah empat negara OKI lainnya. Hasil IRF menunjukkan terdapat efek permanen pada volatilitas pasar saham syariah negara OKI akibat guncangan yang diberikan. Namun, respon volatilitas relatif kecil karena kontribusi guncangan lebih didominasi oleh pasar saham itu sendiri, An integrated stock market has negative impacts, such as accelerating co-movement, which is vulnerable to economic shocks and global market crises on the domestic market. One of the crises in 2022 was the Russia-Ukraine war which impacted the stock market, including Sharia stocks which were believed to be more resistant to the shocks of the global crisis. This study examines the development, integration, and response of OIC countries five Islamic stock markets in the Russia-Ukraine war. The method used is VAR/VECM on the DJIMMT25, SPSADS, SPSUUAEDS, JII, DJIMT, SPBMIR, and SPBMIU indices. The results show the same movement in the UAE and Saudi Arabia stock markets, while Turkey experienced a positive trend during the war. The Islamic stock market of the OIC countries during the Russia-Ukraine war was cointegrated. In contrast, the Malaysian stock market influenced the Islamic stock markets of the other four OIC countries. The IRF results show a permanent effect on the volatility of the Islamic stock market in OKI countries due to the shocks given. However, the volatility response is relatively small because the stock market itself dominates the contribution of shocks.
Keyword: co-movement, OIC, Rusia-Ukraine war, sharia stock market integration