Threshold limit theorems in the theory of rumors, snowball sampling and epidemics

1990 ◽  
pp. 184-188 ◽  
Author(s):  
Anders Martin-Löf
Keyword(s):  
Limit Theorems ◽  
Snowball Sampling ◽  
Threshold Limit

Symmetric sampling procedures, general epidemic processes and their threshold limit theorems

1986 ◽  
Vol 23 (02) ◽  
pp. 265-282 ◽  
Author(s):  
Anders Martin-Löf
Keyword(s):  
Limit Distribution ◽  
Limit Theorems ◽  
General Type ◽  
Finite Population ◽  
Binomial Sampling ◽  
Threshold Limit ◽  
Iterative Sampling ◽  
Factorial Series ◽  
Sampling Procedures ◽  
Symmetric Sampling

Iterative sampling procedures of a general type in a finite population are considered. They generalize the Reed-Frost process in that binomial sampling is replaced by an arbitrary symmetric sampling defined by a factorial series distribution. Threshold limit theorems are proved saying that the total number of sampled objects is either small with a certain limit distribution, or a finite fraction of the population with a Gaussian limit distribution as the size of the population gets large. These results extend earlier ones for the Reed-Frost process [1], and are proved in a more direct way than before.

Symmetric sampling procedures, general epidemic processes and their threshold limit theorems

1986 ◽  
Vol 23 (2) ◽  
pp. 265-282 ◽  
Author(s):  
Anders Martin-Löf
Keyword(s):  
Limit Distribution ◽  
Limit Theorems ◽  
General Type ◽  
Finite Population ◽  
Binomial Sampling ◽  
Threshold Limit ◽  
Iterative Sampling ◽  
Factorial Series ◽  
Sampling Procedures ◽  
Symmetric Sampling

Iterative sampling procedures of a general type in a finite population are considered. They generalize the Reed-Frost process in that binomial sampling is replaced by an arbitrary symmetric sampling defined by a factorial series distribution. Threshold limit theorems are proved saying that the total number of sampled objects is either small with a certain limit distribution, or a finite fraction of the population with a Gaussian limit distribution as the size of the population gets large. These results extend earlier ones for the Reed-Frost process [1], and are proved in a more direct way than before.

Limit theorems and price changes in financial markets

1998 ◽  
Vol 77 (5) ◽  
pp. 1353-1356
Author(s):  
Rosario N. Mantegna, H. Eugene Stanley
Keyword(s):  
Financial Markets ◽  
Limit Theorems ◽  
Price Changes

Hubungan Alexithymia dengan Kecanduan Media Sosial pada Remaja di Jakarta Selatan

2020 ◽  
Vol 1 (2) ◽  
pp. 9
Author(s):  
Yunita Mansyah Lestari ◽  
Suzy Yusna Dewi ◽  
Aulia Chairani
Keyword(s):  
Social Media ◽  
Interpersonal Relationships ◽  
P Value ◽  
Snowball Sampling ◽  
Research Subjects ◽  
Chi Square ◽  
Toronto Alexithymia Scale ◽  
Social Media Addiction ◽  
Consecutive Sampling ◽  
Tas 20

ABSTRAK   Alexithymia ditandai dengan ketidakmampuan dalam mengenali dan mengekpresikan emosi serta pemikiran yang berorientasi eksternal sehingga mereka memiliki hubungan interpersonal yang buruk. Remaja dengan alexithymia cenderung menjadi kecanduan media sosial.Penelitian ini bertujuan untuk mengetahui hubungan antara Alexithymia terhadap kecanduan media sosial pada remaja di Jakarta Selatan. Subjek penelitian adalah remaja yang berusia 13-19 tahun dan tinggal di Jakarta selatan. Pengambilan data menggunakan metode consecutive sampling dan snowball sampling dengan menyebar kuesioner menggunakan link googleform. Jumlah subjek penelitian sebanyak 207 orang (41 = laki-laki, 166 = perempuan). Skala yang digunakan adalah Toronto Alexithymia Scale (TAS-20) dan Social Media Disorder (SMD). Analisa data menggunakan metode chi-square pada SPSS 25. Hasil penelitian didapatkan 85 orang mengalami alexithymia, 88 mengalami kecanduan dan 62 orang mengalami alexithymia dan kecanduan media sosial. p-value didapatkan 0,000. Hal ini berarti terdapat hubungan antara Alexithymia dengan Kecanduan Media Sosial pada remaja di Jakarta Selatan. Kata Kunci :Alexithymia, Kecanduan Media Sosial, Remaja     ABSTRACT   Alexithymia is characterized by an inability to recognize and express emotions and have external oriented thoughts so that they have poor interpersonal relationships. Teenagers with alexithymial tend to become addicted to social media. This study aims to determine the relationship between Alexithymia towards social media addiction in adolescents in South Jakarta. The research subjects were adolescents aged 13-19 years and lived in south Jakarta. Retrieval of the data was using consecutive sampling and snowball sampling method by distributing questionnaires using the googleform link. The number of research subjects was 207 people (41 = men, 166 = women). The scale was used is the Toronto Alexithymia Scale (TAS-20) and Social Media Disorder (SMD). Data analysis using the chi-square method in SPSS 25. The results showed that 85 people had alexithymia, 88 were addicted and 62 people had alexithymia and were addicted to social media. p-value obtained is 0,000. This means that there is a relationship between Alexithymia and Social Media Addiction in adolescents in South Jakarta. Keyword : Adolescents, Alexithymia, Social Media Addiction

Drug abuse and drug addiction among students of University of Rajshahi

2020 ◽  
Vol 11 (3) ◽  
pp. 21-32
Author(s):  
Faiqua Tahjiba
Keyword(s):  
Drug Abuse ◽  
Drug Addiction ◽  
Actual Condition ◽  
Snowball Sampling ◽  
Case Study Method ◽  
Monthly Expenditure ◽  
Physical Problems ◽  
Depth Interview ◽  
Research Show

Objectives: The aim of this study was to investigate the actual condition of the students of University of Rajshahi (RU) regarding drug abuse and addiction. Using case study method the research was conducted with four objectives: (a) to find out how respondents began drug abuse; (b) to discover the causes of their drug addiction; (c) to understand the process of their drug abuse; and (d) to find out the economic, social and health effects of drug abuse. Methods: Case study method was used in this research. Through snowball sampling 18 drug- addicted students of RU were selected as respondents. In-depth interview with a schedule was used to collect data from the respondents in January 2019. Results: Findings of the study show that the causes of drug addiction included curiosity, frustration, friends’ request, neglect from family and friends etc. The drugs which they usually abused were Yaba, Phensydyle, Ganja (Weed), Chuani etc. Their average monthly expenditure for collecting drugs was in between Taka 8,000-10,000. They collected those drugs from rickshaw pullers at different points within the campus and from Mizaner Mor, Budhpara slum and other places outside the campus. The respondents opined that drugs were available if sufficient money could be spent. The respondents had senior and junior fellow students and local boys as companions while taking drugs. Most of them faced physical problems after taking drugs, and some of them tried to get rid of this curse of drug addiction. Conclusion: The findings of this research show that the rate of drug addiction among the students of RU was quite alarming. Therefore, all stakeholders including the students, guardians, teachers, university authority, the law makers and law enforcing agencies, researchers, civil society, NGO’s and the state must come forward together to combat this formidable foe.

PERSEPSI MASYARAKAT TERHADAP PERAN TUMBUHAN ETNOFARMAKA TEMU IRENG DI KECAMATAN RUBARU

2019 ◽  
Vol 1 (2) ◽  
pp. 15-24 ◽  
Author(s):  
Nurul Latifah
Keyword(s):  
Snowball Sampling ◽  
Purposive Sampling

Penelitian ini dilaksanakan di Kecamatan Rubaru Kabupaten Sumenep. Kecamatan Rubaru merupakan salah satu Kecamatan yang terletak di Kabupaten Sumenep dan juga dikenal sebagai pusat pembuatan ramuan obat tradisional. Sejak dahulu secara turun temurun masyarakat Rubaru telah memanfaatkan tumbuhan sebagai bahan dasar pengobatan tradisional untuk mengobati segala macam penyakit. Penelitian ini menggunakan metode deskriptif kuantitatif. Metode pengambilan sampel yang akan digunakan dalam penelitian ini adalah purposive sampling dan snowball sampling. Purposive sampling merupakan teknik sampling yang dipilih secara sengaja dengan pertimbangan bahwa responden mempunyai pengaruh cukup penting dan memiliki banyak informasi tentang tanaman obat temu ireng. Selanjutnya menggunakan teknik Snowball sampling yang merupakan teknik pengambilan sampel yang menggali data melalui metode wawancara dari satu responden ke responden yang lain, sampai peneliti tidak menemukan informasi baru lagi. Untuk menjawab rumusan masalah yang tersebut data yang diperoleh dalam penelitian ini dikumpulkan dan kemudian dianalisis dengan menggunakan analisis deskriptif. Penjabaran analisis ini menggunakan Skala Likert. Hasil penelitian ini menunjukkan bahwa persepsi masyarakat terhadap peran tumbuhan etnofarmaka temu ireng di Kecamatan Rubaru Kabupaten Sumenep dapat dikategorikan setuju.  Hal ini menunjukkan masyarakat setuju bahwa  tumbuhan temu ireng merupakan tanaman obat yang  memiliki peran yang sangat penting bagi kesehatan masyarakat dan membawa dampak yang sangat baik bagi masyarakat. Selain itu masyarakat juga meyakini bahwa temu ireng bermanfaat untuk menyembuhkan penyakit.  

An Exploratory Study of Trade Union Pluralism in Ghana

2019 ◽  
Vol 42 ◽  
Author(s):  
Kenneth E. Parku ◽  
Yvonne Ayerki Lamptey
Keyword(s):  
Trade Union ◽  
Snowball Sampling ◽  
Freedom Of Association ◽  
Cross Sectional ◽  
Trade Union Movement ◽  
Union Movement ◽  
Legal Provisions ◽  
Enterprise Level ◽  
The Government ◽  
Cross Sectional Design

The practice of trade union pluralism at an enterprise level is seen as problematic for both the management of enterprises and the trade union movement. The problems arise from inter-union rivalries, competition and disputes over demarcations of privileges and rights. This article explores the practice of trade union pluralism at the enterprise level in Ghana with the aim of creating awareness of the effect of the practice on the general trade union movement. This qualitative study employed a cross-sectional design and used purposive and snowball sampling methods in selecting the participants. The data was analysed thematically. The findings from the study show that union pluralism is stimulating the decline in general union membership, the breakaway of local unions from the federations, and employers’ classification of workers based on their qualifications once they are employed by organisations, and their assignment to specific unions (automatic membership at enterprise level). It is suggested that employment laws encourage union breakaways, which weakens the unions especially at the enterprise level. It is recommended that the state, labour officials and policy-makers should enforce labour laws, especially regarding freedom of association, and consider revisiting or amending some labour laws to curb their abuse. The government and labour institutions need to work together to operationalise the implementation of legal provisions on freedom of association or consider amending the provisions to curb the existing abuse.

Experiential Learning in Graduate Archival Education at the University of Botswana

Mousaion ◽  
2019 ◽  
Vol 37 (1) ◽  
Author(s):  
Olefhile Mosweu
Keyword(s):  
Experiential Learning ◽  
Work Experience ◽  
Real Life ◽  
Opportunity To Learn ◽  
Theory And Practice ◽  
Records Management ◽  
Archival Theory ◽  
Snowball Sampling ◽  
The Real ◽  
The University

Most curriculum components of archival graduate programmes consist of contextual knowledge, archival knowledge, complementary knowledge, practicum, and scholarly research. The practicum, now commonly known as experiential learning in the global hub, is now widely accepted in library and information studies (LIS) education as necessary and important. It is through experiential learning that, over and above the theoretical aspects of a profession, students are provided with the opportunity to learn by doing in a workplace environment. The University of Botswana’s Master’s in Archives and Records Management (MARM) programme has a six weeks experiential learning programme whose purpose is to expose prospective archivists and/or records managers to the real archival world in terms of practice as informed by archival theory. The main objective of the study was to determine the extent to which the University of Botswana’s experiential learning component exposes students to real-life archival work to put into practice theoretical aspects learnt in the classroom as intended by the university guidelines. This study adopted a qualitative research design and collected data through interviews from participants selected through purposive and snowball sampling strategies. Documentary review supplemented the interviews. The data collected were analysed thematically in line with research objectives. The study determined that experiential learning does indeed expose students to the real world of work. It thus helps to bridge the gap between archival theory and practice for students without archives and records management work experience. For those with prior archival experience, experiential learning does not add value. This study recommends that students with prior archives and records management experience should rather, as an alternative to experiential learning, undertake supervised research, and write a research essay in a chosen thematic area in archives and records management.

Cytisine as an alternative smoking cessation product for Pacific smokers in New Zealand

2018 ◽  
Vol 21 (2) ◽  
pp. 89-95
Author(s):  
Vili Nosa ◽  
Kotalo Leau ◽  
Natalie Walker
Keyword(s):  
Smoking Cessation ◽  
New Zealand ◽  
Nicotinic Acetylcholine Receptors ◽  
Cultural Practices ◽  
Partial Agonist ◽  
Snowball Sampling ◽  
Structured Interviews ◽  
Liquid Form ◽  
Pacific People ◽  
The Pacific

ABSTRACT Introduction: Pacific people in New Zealand have one of the highest rates of smoking.  Cytisine is a plant-based alkaloid that has proven efficacy, effectiveness and safety compared to a placebo and nicotine replacement therapy (NRT) for smoking cessation.  Cytisine, like varenicline, is a partial agonist of nicotinic acetylcholine receptors, and blocks the rewarding effects of nicotine. Cytisine is naturally found in some plants in the Pacific region, and so may appeal to Pacific smokers wanting to quit. This paper investigates the acceptability of cytisine as a smoking cessation product for Pacific smokers in New Zealand, using a qualitative study design. Methods: In December 2015, advertisements and snowball sampling was used to recruit four Pacific smokers and three Pacific smoking cessation specialists in Auckland, New Zealand. Semi-structured interviews where undertaken, whereby participants were asked about motivations to quit and their views on smoking cessation products, including cytisine (which is currently unavailable in New Zealand). Interviews were recorded and transcribed verbatim, with thematic analysis conducted manually. Findings: Pacific smokers reported wanting to quit for loved ones and family, but did not find currently available smoking cessation products effective. Almost all participants had not previously heard of cytisine, but many of the Pacific smokers were keen to try it. Participants identified with cytisine on a cultural basis (given its natural status), but noted that their use would be determined by the efficacy of the medicine, its cost, side-effects, and accessibility. They were particularly interested in cytisine being made available in liquid form, which could be added to a “smoothie” or drunk as a “traditional tea”.  Participants thought cytisine should be promoted in a culturally-appropriate way, with packaging and advertising designed to appeal to Pacific smokers. Conclusions: Cytisine is more acceptable to Pacific smokers than other smoking cessation products, because of their cultural practices of traditional medicine and the natural product status of cytisine.

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