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All Journal Journal of Tropical Life Science : International Journal of Theoretical, Experimental, and Applied Life Sciences JURNAL GIZI INDONESIA Jurnal Ilmu Dasar Epsilon: Jurnal Matematika Murni dan Terapan Jurnal Keolahragaan AcTion: Aceh Nutrition Journal BAREKENG: Jurnal Ilmu Matematika dan Terapan Biosaintifika: Journal of Biology & Biology Education Specta Journal of Technology Journal of Fundamental Mathematics and Applications (JFMA) PIKAT Prosiding Seminar Nasional Unimus
Kartika Nugraheni
Prodi Matematika Jurusan Matematika FMIPA Universitas Brawijaya
Agriculture, Biological Sciences & Forestry Humanities Chemical Engineering, Chemistry & Bioengineering Civil Engineering, Building, Construction & Architecture Computer Science & IT Control & Systems Engineering Decision Sciences, Operations Research & Management Economics, Econometrics & Finance Electrical & Electronics Engineering Energy Engineering Environmental Science Health Professions Immunology & microbiology Mathematics Mechanical Engineering Medicine & Pharmacology Nursing Physics Public Health Transportation Other

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Perubahan pengetahuan penjamah makanan hotel setelah penyuluhan higiene perorangan Kusuma, Hapsari Sulistya; Pasanda, Amalia; Nugraheni, Kartika; Nissa, Choirun
Jurnal Gizi Indonesia (The Indonesian Journal of Nutrition) Vol 6, No 1 (2017)
Publisher : Department of Nutrition Science, Faculty of Medicine, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (347.531 KB) | DOI: 10.14710/jgi.6.1.71-75

Abstract

Background : Personal hygiene food handlers in food processing is very important because with the application of good hygiene can minimize the possibility of food contamination. The personal hygiene can be influenced by some factors, for instance knowledge and behaviors of food handlers. Lack of knowledge, inappropriate behaviors towards personal hygiene can be changed by giving the right information. Objective : This study aims to determine differences in knowledge of food handlers before and after counseling.Methods : This was a quasi-experimental one group pretest posttest design. The sample of this study was 18 food handlers in Patra Jasa Hotel selected by total sampling method. Knowledge data obtained from the total score from the correct answer in the questionnaire. The data was analyzed using Wilcoxon test.Results : This study showed that the increases in knowledge of food handlers increased by 22%. Statistical analysis showed knowledge before and after nutrition extension (p = 0.001).Conclusions : there was difference in knowledge of food handlers before and after personal hygiene counseling.
SIMULASI PERGERAKAN TUMPAHAN MINYAK DI LAUT DENGAN PENGARUH ANGIN Millah, Nashrul; Anggriani, Indira; Nugraheni, Kartika
SPECTA Journal of Technology Vol 3 No 3 (2019): SPECTA Journal of Technology
Publisher : LPPM ITK

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35718/specta.v3i2.67

Abstract

As a petroleum-producing country, Indonesia has a very important role in supplying national and international petroleum needs. The distribution of oil by sea raises the risk of spills and harms the marine environment, especially for marine life. Most oil spills in the marine environment can form a thin layer on the surface due to the movement of wind, waves, and currents. In this study, the oil spill movement model used the Shallow Water Equation (SWE) model and the equation for the movement of oil spills. The SWE model consists of the equation of mass and momentum derived from the law of conservation of mass which is derived into the equation of continuity and the law of conservation of momentum which is derived into the equation of conservation of momentum. In this model, ocean currents are affected by several disturbances in the form of wind gusts and friction with the bottom. The model is solved numerically through simulation using the finite volume method. Discretization is done by using a staggered grid approach, where the mass and momentum variables are discretized in different cells. From the simulation results, it appears that the movement of oil spills is influenced by wind direction and current. The simulation results also found that the speed of the movement of oil spills has increased in the early times, but then gradually.  
Dynamics of a Fractional Order Eco-Epidemiological Model Nugraheni, Kartika; Trisilowati, Trisilowati; Suryanto, Agus
Journal of Tropical Life Science Vol 7, No 3 (2017)
Publisher : Journal of Tropical Life Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11594/jtls.07.03.09

Abstract

In this paper, we propose a fractional order eco-epidemiological model. We considere the existence of time memory in the growth rate of the three populations. We observed the dynamical behaviour by analysing with fractional order and then simulateing using Grünwald-Letnikov approximation to support analytical results. It found that the model has five equilibrium points, namely the origin, the survival of susceptible prey, the predator free equilibria, the infected prey free equilibria, the interior equilibria. Numerical simulations show that the existence of fractional order  is a factor which affects the behaviour of solutions. 
OPTIMAL CONTROL OF MATHEMATICAL MODELS IN BIOENERGY SYSTEMS AS EMPOWERMENT OF SUSTAINABLE ENERGY SOURCES Nugraheni, Kartika; Soemarsono, Annisa Rahmita; Millah, Nashrul; Anggriani, Indira; Usrotus Wakhidah, Ummi Saydatul
Journal of Fundamental Mathematics and Applications (JFMA) Vol 7, No 1 (2024)
Publisher : Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jfma.v7i1.22482

Abstract

Energy has a very important role in everyday life. Dependence on non-renewable energy increases its vulnerability to supply instability, making it important to seek alternative energy sources to overcome this dependence. Bioenergy is an alternative energy produced from organic materials such as biomass. Control of renewable energy is needed to increase production and empowerment. In this research, a mathematical model of biogas production growth in the form of differential equations formed with optimal control modifications is proposed. Completion of the model is carried out by forming an objective function, as well as determining the Hamilton function and Lagrange function. Numerical simulations in the model show that providing control can increase biogas production as a sustainable energy source.
The Improvement of Lipid Profiles and Glucose Resistance of Hypercholesterolemic Rats using Tempeh Flour Based-Yoghurt Complemented with Red Pitaya Peel Extract Nugraheni, Kartika; Putriningtyas, Natalia Desy; Fernando, G. S.N.; Bintari, Siti Harnina
Biosaintifika: Journal of Biology & Biology Education Vol 15, No 3 (2023): December 2023
Publisher : Department of Biology, Faculty of Mathematics and Sciences, Semarang State University . Ro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/biosaintifika.v15i3.47414

Abstract

Tempeh flour is potentially a substitute material in making yoghurt that provides bioactive for improving cardiovascular health. It is also suitably combined with antioxidant sources, such as red pitaya peel extract, which is well known for inhibiting metabolic inflammation. This study aims to analyze the effectiveness of tempeh flour-based yoghurt complemented with red pitaya peel extract in improving lipid profiles and glucose tolerance in hypercholesterolemic rats. A total of 36 male Wistar rats were used and divided into six different groups: regular diet (ND) and five high-fat-diet rat groups treated with no supplementation (HFD); diary-based yoghurt with lactic acid bacteria (YBAL); commercial yoghurt (YB); tempeh flour based-yoghurt with lactic acid bacteria (SY); and tempeh flour based yoghurt complemented with red pitaya peel extract (SDS). The supplementation of each treatment group was given a dose of 3.6 ml/ KgBW/ day as a single dose for 28 days. The blood sample was collected from sinus orbitalis and then used for lipid profile, glucose, liver enzyme analysis, and statistical analysis using ANOVA. The result shows that glucose levels increased significantly in all groups, except HFD groups, and there is no significant difference between normal and yoghurt treatment groups. However, yoghurt and red pitaya peel extract supplementation significantly decrease LDL-C and increase HDL-C levels while improving liver condition during hypercholesterolemia. In conclusion, tempeh flour-based yoghurt complemented with red pitaya peel extract can improve lipid profile and liver health in hypercholesterolemia rats. Therefore, further research on metabolism pathways is needed to develop potential nutraceutical products for people with hypercholesterolemia.
Analysis of Mangrove Forest Resource Depletion Models due to The Opening of Fish Pond Land with Time Delay Wakhidah, Ummi Usrotus Saydatul; Nugraheni, Kartika; Winarni, Winarni
Jurnal ILMU DASAR Vol 23 No 1 (2022)
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Jember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.19184/jid.v23i1.23889

Abstract

Mangrove forest is an ecosystem with many resources and high biological diversity that contain many species of animal, such as proboscis monkeys. One of the problems that keep happening on mangrove forest is the opening of fish pond. Opening of fish pond can damage mangrove resource by the degradation of the mangrove habitat. This study aims to analyze the depletion stability model of mangrove forest resources with time delay, and to show effect of time delay and the presence of change in the equilibrium point (Hopf bifurcation) on depletion stability model of mangrove forest resources due to fish pond openings. The depletion stability model of mangrove forest resources can be modeled as a system of nonlinear differential equations. In the numerical simulation results, critical value of delay (τ0) is 7.05 and the transverse conditions are not fulfilled. This mean there is no change in stability and the delay time parameter (τ) does not affect the stability of the system. System will remain stable when the mangrove forests, proboscis monkeys, and fish ponds are in equilibrium. In other words, mangrove forests, proboscis monkeys, and fish ponds can coexist even though time delays, and the analysis using the Hopf bifurcation cannot be carried out.
Faktor Risiko Kejadian Stunting di Wilayah Puskesmas Karangdoro Kota Semarang Prihatiningrum, Felin Aulia; Safitri, Anugrahaning Dyah; Susantini, Purwanti; Ayunintyas, Rr. Annisa; Nugraheni, Kartika
Prosiding Seminar Nasional Unimus Vol 7 (2024): Transformasi Teknologi Menuju Indonesia Sehat dan Pencapaian Sustainable Development G
Publisher : Universitas Muhammadiyah Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Prevalensi stunting di Puskesmas Karangdoro sebesar 5,55%, belum mencapai target KotaSemarang yang zero stunting. Kejadian stunting diduga berhubungan dengan beberapa faktor, sepertiriwayat KEK dan anemia kehamilan, BBLR, ASI eksklusif, serta hygiene sanitasi. Tujuan penelitian iniuntuk menganalisis faktor risiko yang menyebabkan kejadian stunting di wilayah Puskesmas Karangdoro.Penelitian analitik observasional dengan desain case control study, dilakukan terhadap 60 sampel yangterdiri dari 30 kasus yang dipilih menggunakan Total Sampling dan 30 kontrol menggunakan MatchingSampling lalu Sample Random Sampling. Data riwayat berat badan lahir, ASI eksklusif serta hygienesanitasi dikumpulkan dengan metode wawancara menggunakan kuesioner, lalu riwayat KEK dan anemiadiperoleh dari data sekunder yaitu dari buku KIA. Analisis faktor risiko dilakukan dengan menghitung ORmenggunakan tabel 2x2. Hasil penelitian menunjukkan sebesar 33,3% ibu hamil anemia, 13,3% ibu hamilKEK, 30% bayi dengan BBLR, 41,7% pemberian ASI tidak eksklusif, dan 83,3% keluarga dengan hygienesanitasi kurang. Ibu anemia (OR = 3,500), ibu KEK (OR = 1,800), bayi BBLR (OR = 2,895), pemberianASI eksklusif (OR = 1,147), dan keluarga dengan hygiene sanitasi kurang (OR = 2,739) adalah faktor risikokejadian stunting. Ibu anemia lebih berisiko 3,5 kali memiliki balita stunting, ibu KEK lebih berisiko 1,8kali memiliki balita stunting, bayi BBLR lebih berisiko 2,8 kali menjadi stunting, pemberian tidak ASIeksklusif lebih berisiko 1,1 kali memiliki balita stunting, dan keluarga dengan hygiene sanitasi yang kurangakan berisiko 2,7 kali memiliki balita stunting. Kata Kunci : anemia, ASI eksklusif, BBLR, hygiene sanitasi, KEK, stunting.
Total Bakteri Asam Laktat dan Total Padatan Terlarut Yoghurt Kelapa dengan Penambahan Bunga Telang Berdasarkan Lama Penyimpanan Safitri, Yuliani Dewi; Nugraheni, Kartika; Fitriyanti, Addina Rizky; Isworo, Joko Teguh
Prosiding Seminar Nasional Unimus Vol 7 (2024): Transformasi Teknologi Menuju Indonesia Sehat dan Pencapaian Sustainable Development G
Publisher : Universitas Muhammadiyah Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Prevalensi intoleransi laktosa di Indonesia pada anak usia anak-anak berusia 3-5 tahun yaitu 21,3%, usia 611 tahun sebesar 57,8%, dan usia 12-14 tahun sebesar73%. Pada lansia di Indonesia sebesar 66%. Yoghurt kelapa merupakan salah satu alternatif solusi yang dapat dijadikan makanan fungsional bagi penderitaintoleransi laktosa. Tujuan dari penelitian ini yaitu untuk mendeskripsikan total bakteri asam laktat dan total padatan terlarut yoghurt kelapa dengan penambahan bunga telang berdasarkan waktu simpan pada suhu dingin yaitu 5°C. Penelitian dilakukan secara eksperimental dengan desain rancangan acak lengkap.Variasi waktu simpan yang digunakan adalah 0,1,3,5,7 dengan 5 kali pengulangan. Data dianalisis secara kualitatif dengan menggunakan SNI 2981:2009 mengenai yoghurt sebagai acuan untuk menilai kualitas produk yang dihasilkan. Total bakteri asam laktat pada yoghurt kelapa dengan penambahan bunga telangmengalami fluktuasi selama masa penyimpanan yaitu diperoleh nilai tertinggi hari ke-3 sebesar 2,37 x 10 koloni/ml, dan terendah pada hari ke-7 sebesar 1,22x107 koloni/ml. Total padatan terlarut pada yoghurt kelapa dengan penambahan bunga telang mengalami penurunan dengan hasil total padatan terlarut tertinggipada hari penyimpanan ke-0 yaitu sebesar 9,04°Brix dan terendah pada hari ke-7 sebesar 6,58°Brix. Produk yoghurt kelapa belum dapat menjadi alternatif yoghurt susu sapi karena tidak memenuhi SNI.Kata Kunci : Bunga telang, lama penyimpanan, total BAL, total padatan terlarut, yoghurt kelapa.
PENERAPAN ALGORITMA HILL CIPHER DAN PERMUTASI PADA SISTEM KRIPTOGRAFI POLYALPHABETIC Lukmaini, Sindi; Wira Tama, Yanuar Bhakti; Nugraheni, Kartika
EPSILON: JURNAL MATEMATIKA MURNI DAN TERAPAN (EPSILON: JOURNAL OF PURE AND APPLIED MATHEMATICS) Vol 18, No 2 (2024)
Publisher : Mathematics Study Program, Faculty of Mathematics and Natural Sciences, Lambung Mangkurat

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20527/epsilon.v18i2.12845

Abstract

TTechnological advances have a great influence on facilitating long-distance communication, one of which is exchanging messages. The security of a message is an important aspect of protecting sensitive information. Cryptography is a branch of science that aims to maintain the confidentiality, integrity, and authenticity of messages in communication. One of the cryptographic methods used is Hill Cipher, which converts plaintext into ciphertext using a key matrix, but Hill Cipher is vulnerable to cryptanalysis attacks, especially if the key matrix is not chosen properly. Based on these problems, this research was conducted by applying the Hill Cipher algorithm with permutation as an additional layer of security. This study aims to analyze the effect of the message and key matrix on the performance of computation time in the encryption and decryption process of Hill Cipher combined with permutation, where the message characters are limited to 26 alphabetic characters and the use of Hill block length and permutation techniques is set at 5 characters. The simulation results show the average performance of computation time on the encryption and decryption process is 0.000083199 seconds and 0.000113493 seconds for a message with 707 characters. The key matrix used must be invertible, and the performance of computation time on encryption and decryption with different keys is 0.000094817 seconds and 0.00025938 seconds.
STABILITY ANALYSIS OF GAMBLING BEHAVIOR MODEL WITH COGNITIVE BEHAVIORAL THERAPY TREATMENT Asfa Niswah, Fazat; Nugraheni, Kartika; Fitria, Irma; Dewanti, Retno Wahyu
BAREKENG: Jurnal Ilmu Matematika dan Terapan Vol 19 No 3 (2025): BAREKENG: Journal of Mathematics and Its Application
Publisher : PATTIMURA UNIVERSITY

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30598/barekengvol19iss3pp1879-1892

Abstract

Gambling, driven by the desire for quick profits, involves individuals or groups betting money, often resulting in significant financial consequences. Gambling behavior can be influenced by the environment or society. Thus, the dynamics of environmental influences on gambling behavior can be mathematically modeled using differential equations. This study presents a mathematical model of the environmental impact on the dynamics of the SI1I2T (Susceptible-Infective1-Infective2-Treatment) population of gamblers undergoing cognitive behavioral therapy (CBT). The model replaces the recovered sub-population with a treatment sub-population, representing individuals receiving CBT, as there is no definitive cure for gambling addiction. It consists four sub-populations: It consists of four sub-populations: (S) individuals susceptible to gambling, (I₁) gamblers who are not yet addicted, (I₂) addicted gamblers, and (T) individuals undergoing treatment but at risk of relapse. Mathematical analysis identifies two equilibrium points: a gambling-free equilibrium and an endemic gambling equilibrium. Furthermore, the results of the stability analysis using the linearization method shows that the balance point has a asymptotically stability characteristic requirement. The basic reproduction number ( ) was calculate and resulted if < 1, then the free gambler population equilibrium point is asymptotically stable, and vice versa. Based on the results of the data analysis, the value of = 0.5. This value is less than 1, so the equilibrium point obtained is the free gambler population and asymptotically stable equilibrium point. This means that the population will be free from gambling behavior. Numerical simulation represents the results of the analysis that has been obtained. Providing cognitive behavioral therapy (CBT) to gamblers in treatment can help reduce the gambler population. The population growth will decrease in such a way that it will eventually lead to a gambling-free population
Co-Authors Ali Khomsan Ali Rosidi Anggriani, Indira Aprilia Indra Kartika, Aprilia Indra Asfa Niswah, Fazat Asihanto, Balqis Aureola Putri Ayunintyas, Rr. Annisa Catherina, Angela Dewi, Luthfia Fernando, G. S.N. Fitria, Irma Fitriyanti, Addina Rizky Hapsari Sulistya Kusuma Istianty, Ari Joko Teguh Isworo Lukmaini, Sindi M.Pd S.T. S.Pd. I Gde Wawan Sudatha . Maulida, Fitra Millah, Nashrul Muhammad Muhibbi Mustakim Mustakim Natalia Desy Putriningtyas, Natalia Desy Nissa, Choirun Pabannu, Alfian Pasanda, Amalia Pinda Ayu Widiyani Prihatiningrum, Felin Aulia Purwanti Susantini Rahajoe, Toeti Retno Wahyu Dewanti Safitri, Anugrahaning Dyah Safitri, Yuliani Dewi Siti Harnina Bintari Soemarsono, Annisa Rahmita Trisilowati Trisilowati, Trisilowati Usrotus Wakhidah, Ummi Saydatul Wakhidah, Ummi Usrotus Saydatul Winarni Winarni Yanuar Bhakti Wira Tama Yogaswara, Andre