Multiple Sampling Techniques Research Articles

On control charts based on generalized multiple dependent state sampling

ABSTRACT We clarify the use of the widely used multiple dependent state sampling (MDSS) technique and its generalization (GMDSS) with control charts. We show that these rules are simple modifications of well-known supplementary runs rules. The MDSS and GMDSS rules are inefficient; however, they do not distinguish between the upper and lower warning regions. We show that the application of the more conventional supplementary runs rules, i.e. those side-sensitive with respect to the warning regions, provides significantly better performance than the MDSS and GMDSS techniques. In addition, we show that a commonly used expression for determining the average run length of the GMDSS method is incorrect and provide a Markov chain alternative approach.

Insecurity and Communal Conflicts in Akwa Ibom State, Nigeria

Communal Conflicts is a social problem that affects a significant number of communities in Akwa Ibom States and Nigeria in general. Some lingering Communal Conflicts have affected the past generations, present generation and also attempting to affect future generations if not properly resolved. Most communal conflicts in Akwa Ibom State are direct consequences of the lack of proper demarcation of the boundaries between these communities. The main objective of the study was to investigate the factors that necessitate communal conflicts among communities in Akwa Ibom State. The study adopted a survey design. Data were obtained from two sources; Primary Source and Source. Primary data were obtained through interviews and participant observation, while secondary data were obtained from extant literature. Respondents were selected using multiple sampling techniques, this includes purposive, Snowball and random sampling techniques. Two Sociological theories were used to explain the study these include, the Human Need Theory and the Frustration-Aggression Theory. The study recommends (amongst others) that the government should constitute a Panel that would fix Proper boundary demarcation between these communities. The reports of a panel of inquiry "White paper" should be properly implemented to forestall future communal conflicts in Akwa Ibom State. Government should do away with every form of political interest and bias to ensure that Peace is restore among the warring Communities.

Power Outage and Vandalism in Akwa Ibom State, Nigeria

There are prevalent cases of vandalism on the national grid which usually throws Akwa Ibom State and Nigeria into darkness due to power outages. Transmission Company of Nigeria (TCN) is facing serious challenges of vandalism on electricity facilities across the country as it affects power supply, a situation that has become a social problem affecting both the rich and the poor. This study was conducted to examine the cause of power outage in Akwa Ibom State, Nigeria. Participants were selected using multiple sampling techniques; this includes purposive, snow-ball and simple sampling techniques. Primary data were collected through interview and participant observation. Secondary data were collected from extant literature to make it more scientific. The study recommends that the government should provide a security network that would protect electricity facilities across the state. Government should prosecute any vandal caught sabotaging electricity facilities in the state.

The detrimental effect of socio-economic factors on cotton productivity in the tribal region of Odisha

Cotton is a crucial cash crop in the tribal belt of Odisha. It has a significant effect on the livelihood of the tribal people. The volatile socio-economic background of the tribal farmers is a major hindrance to the proper development of the agriculture sector. In this regard, it is important to study the possible factors affecting cotton productivity in the tribal region to boost the policy effectiveness for the development of this cash crop in the area. More precisely, how is their socio-economic condition reflected in their crop productivity? So, the development of the tribal farmers can develop this crop in the region. This study analyses the detrimental effect of socio-economic factors on cotton productivity in the tribal area of Odisha. The data are collected using a structured questionnaire and a multiple-sampling technique. To understand the effect of socioeconomic factors on productivity, the ordinary least square (OLS) method has been employed in this paper. The result shows that most of the farmers are illiterate for which productivity is degrading. The age and gender of the head of the household are significant contributors to the cotton productivity of the study area. Male-headed households are more productive than female-headed households. Per capita monthly income and proportion of irrigated land are also important factors to affect cotton productivity positively. However, the social group of the family has no significant effect on the cotton productivity in the study area. Policymakers and agriculturists should emphasize farmer literacy, farmer income and land irrigation facilities to boost the productivity of this crop in the studied region.

Police Brutality and Endsars Protests in Akwa Ibom State, Nigeria

This study seeks to unravel the atrocities of the Nigeria Police Force on innocent Nigerians which led to a nationwide violent protest known as EndSARS. Survey research method was employed for this study and respondents were selected using multiple sampling techniques which include purposive, snowball and simple random sampling techniques. Primary data were collected through interview and participant observation, while secondary data were collected from extant literature. The study applied the Retributive Theory of Justice in order to explain the concept and empirical studies reviewed from other studies for conclusion and recommendations. The findings from the study showed that innocent Nigerians were killed and maimed by men of the Nigeria Police Force at any slightest provocation, without being punished by the law. The study recommends (amongst others) that the government should always ensure that erring police officers are punished to serve as a deterrent in order to reduce the menace of police brutality in Akwa Ibom State and Nigeria in general.

Access and Sustainability of Water Point Sources in Sekyere Kumawu District

The “3K Project” has increased the number of water point sources and the quantity of water available to Sekyere Kumawu District, however, community settlers still struggle to get potable water. The study, therefore, sought to examine the accessibility and sustainability of water point sources in the Sekyere Kumawu District. The descriptive survey was employed. Mixed approach; both quantitative and qualitative research designs were used in the study. Primary data were sourced using structured questionnaires, interview guide and field observations. Multiple stage sampling techniques was employed to select 390 households while 9 key stakeholders were purposively selected. The Statistical Product and Service Solutions was used to process and analyse the data. Both descriptive and inferential statistics such as frequencies, percentages, crosstabs, Pearson Chi-square and paired sample t-test were used in the data analysis to arrive at key findings. Also, interviews were manually transcribed, coded, grouped into themes and used appropriately to either confirm or reject the quantitative analyses whereas observations in the form of pictures from the field were also presented in plates to support the findings from questionnaires and interviews. It was found out that among the various water point sources in the district, pipe borne water was preferred for drinking due to its hygienic nature and quality. It is therefore, recommended that the District Assembly should liaise with water and sanitation NGOs and GWCL to finance water projects expansion within the communities, especially areas where there were spatially deficiency in the water point sources or under-coverage and to newly developed areas in a bid to improve accessibility, especially to access safely managed drinking water services.

Use of multiple sampling techniques for cyanobacteria and cyanotoxin monitoring in the Sacramento-San Joaquin Delta under different hydrologic regimes

Cyanobacteria harmful algal blooms (CHABs) are a growing water quality problem in the upper San Francisco Estuary (California), also known as the Sacramento-San Joaquin Delta. We conducted cyanobacteria and cyanotoxin monitoring from 2020 to 2023, which spanned California's driest consecutive 3-year period and one of the wettest years on record (2023). To assess the impact of CHABs over this range of hydrologic conditions, we monitored invasive Asian Clams (Corbicula fluminea) for microcystin contamination and used molecular tools (qPCR and sequencing) to characterize cyanobacteria in the water column. We also used solid phase adsorption toxin tracking (SPATT) samplers to track microcystins (MCs) and other cyanotoxins in 2023. During the drought years, record breaking MCs, in excess of 1000 μg/L, were documented in water grab samples and Asian clams also accumulated higher MCs relative to the wet year. However, MCs were present in Asian clams during the entire study period. SPATT's confirmed MC presence during wet 2023 and sequencing results corroborated the integrative sampler findings. Yet, no MC was detected in water grab samples at our primary sampling sites during the drought year of 2022 or the wet year of 2023. This highlights the importance of using multiple sampling modalities to provide a more accurate assessment of MC contamination, especially in large estuaries where traditional discrete monitoring can easily miss episodic and transient CHAB events.

A self-adaptive correlated multiple sampling technique based on single-slope ADC for low-noise CMOS image sensors

This paper presents a self-adaptive correlated multiple sampling (SACMS) technique for low-noise CMOS image sensors. Compared to the traditional correlated multiple sampling (TCMS), SACMS technique adds a pre-determination stage to determine the brightness of the pixel, reducing the 4 large-range ramps to 3 small-range ramps and 1 large-range ramp when quantizing the signal. For dark pixels, the signal is quantized using small-range ramps with short sampling interval to reduce low-frequency noise. For bright pixels, the CMS operation is turned off and the signal is quantized only once in the large-range ramp to improve the frame rate. Simulation results demonstrate that, for dark pixels, SACMS achieves a minimum readout noise of 84.22μVrms at eight times analog gain, compared to 108.76μVrms with TCMS, representing an approximately 21.7 % improvement in noise suppression. Additionally, the sampling rate of the SSADC employing SACMS technique is 36.36 kHz, while the sampling rate of the SSADC using TCMS technique is 21 kHz.

The Influence of Accounting Profits, Cash Flow Statements and Company Size on Stock Returns in Manufacturing Companies

This research aims to investigate the impact of several factors on stock returns in manufacturing companies. The research employs a quantitative associative research method and utilizes a multiple regression sampling technique. The sample consists of 15 manufacturing companies listed on the Indonesia Stock Exchange (IDX) during the period 2019-2022, totaling 60 data points from annual financial reports. The partial results of the research reveal that accounting profit and operating cash flow do not have a significant impact on stock returns. However, investment cash flow has a significant effect on stock returns, while financing cash flow and company size do not have a significant influence on stock returns. Overall, the research findings indicate that simultaneously, accounting profit, operating cash flow, investment cash flow, financing cash flow, and company size have a significant impact on stock returns in manufacturing companies. This study provides valuable insights into the factors influencing the stock performance of manufacturing companies and can serve as a guide for investors and decision-makers in managing their portfolios

Supporting business functions influencing the formalization of charcoal business in Tanzania

Charcoal business, production, and sustainability are all under the control of government regulations. In Tanzania, the entire charcoal value chain employs approximately two million people. As a result, there are unreliable records for registered actors, and it is difficult to accurately quantify the annual amount of charcoal production and revenue collected by the Tanzanian government. Supporting functions are legally provided activities and services to support charcoal actors to formalize their business, including participation in the formulation of forest laws, market infrastructure development, training, access to information, and financial services. Supporting business functions available for charcoal actors such as producers, wholesalers, and retailers to facilitate the formalization of the charcoal business in Tanzania. This study was conducted to determine the supporting functions that are important to charcoal actors in Tanzania to formalize their activities. A total of 107 charcoal actors were administered a semi-structured questionnaire using the multiple sampling technique, which involved 31 wholesalers and 42 retailers trading in two of the largest markets, one in Dar es Salaam and the other in Zanzibar. Both markets depend on charcoal production in Handeni district, located in Tanga Region. Principal component analysis (PCA) indicated that formalizing the charcoal sector in Tanzania necessitates public-private partnerships (22.9%), financial services and legal environments (21.9%), and market infrastructures (15.6%). We concluded that the charcoal business needs the collaboration of the government with non-government organizations to share resources such as forest staff, vehicles, and incentives to motivate the participation of actors in the training of the legal procedure of charcoal business management, the formulation of registered charcoal groups or associations, and the establishment of charcoal selling centres. Moreover, the development of forest laws should be participatory to involve charcoal business stakeholders to have a reasonable cost of issuing licenses and other permits.

Design of Low-Noise CMOS Image Sensor Using a Hybrid-Correlated Multiple Sampling Technique

We present a 320 × 240 CMOS image sensor (CIS) using the proposed hybrid-correlated multiple sampling (HMS) technique with an adaptive dual-gain analog-to-digital converter (ADC). The proposed HMS improves the noise characteristics under low illumination by adjusting the ADC gain according to the incident light on the pixels. Depending on whether it is less than or greater than 1/4 of the full output voltage range from pixels, either correlated multiple sampling or conventional-correlated double sampling (CDS) is used with different slopes of the ramping signals. The proposed CIS achieves 11-bit resolution of the ADC using an up-down counter that controls the LSB depending on the ramping signals used. The sensor was fabricated using a 0.11 μm CIS process, and the total chip area was 2.55 mm × 4.3 mm. Compared to the conventional CDS, the measurement results showed that the maximum dark random noise was reduced by 26.7% with the proposed HMS, and the maximum figure of merit was improved by 49.1%. The total power consumption was 5.1 mW at 19 frames per second with analog, pixel, and digital supply voltages of 3.3 V, 3.3 V, and 1.5 V, respectively.

Examining Course Facilitators’ Perspectives on Online Facilitation for Distance Education

The importance of online learning for delivering academic content in distance education cannot be an understatement. Online learning is not only associated with benefits, but it also comes with some challenges among course facilitators in distance education. This study, therefore, examined course facilitators’ perspectives on online facilitation in distance education within the context of a less developed economy. The study adopted the quantitative approach based on descriptive research design with a sample of 529 course facilitators out of a population of 2,768 using multiple sampling techniques such as stratified and simple random sampling. Data were gathered using a structured questionnaire, and partial least squares structural equation modeling (PLS-SEM) was utilized to analyze the results. Findings from the study revealed that course facilitators had online tools and content knowledge but lacked online lesson presentation skills. Availability of online gadgets significantly predicted functionality and online teaching presentation method. Challenges with online learning, availability and functionality of online gadgets, and online presentation methods significantly predicted online use intention and subsequently influenced online usage for teaching among course facilitators. It was recommended that managers of distance education train and provide technical support as well as online gadgets for course facilitators to effectively implement online education. This study provides new insights into how online gadgets, their functionality, and online presentation methods by course facilitators intricately relate among themselves and finally influence online usage intentions and actual usage of online instruction in the distance education milieu.

“At-Risk” Students Self-Efficacy Level and Attitudes Towards Mathematic in the Upper East Region of Ghana

Several studies exist in literature on the attitude of students towards mathematics and the self-efficacy level of students in mathematics in general. However, little is seen on the attitudes of “At-Risk” students towards mathematics and their self-efficacy level in mathematics, hence this study was conducted to fill the gap in literature by examining the attitudes and self-efficacy level of the “At-Risk” students towards/in mathematics in the Upper East Region of Ghana. This investigation is a quantitative one which made use of a cross-sectional survey design to collect data from 104 “At-Risk” students who were selected using multiple sampling techniques. Adopted attitudes towards mathematics inventory by Tapia (1996) and adapted self-efficacy questionnaire by May (2009) were the instruments of data collection. The data collected were analyzed descriptively (means and standard deviations) which were compared with standard levels of interpretations in literature and judgment made. From the analysis of the data, it was found that “At-Risk” students have low mathematics self-efficacy level and moderate attitudes towards mathematics. It was therefore recommended that mathematics teachers should employ innovative and child-centered teaching approaches which have the potential of actively engaging learners during instruction in the subject to help enhance learners’ attitudes and self-efficacy level in mathematics.

Multiple Stool Sampling and Specific Parasitological Technique are Crucial to Diagnose Strongyloidiasis in Alcoholic Patients.

Chronic alcoholism is a well-known risk factor for strongyloidiasis, in these patients the disease is potentially more severe, probably due to the breakdown of local protective barriers and immunosuppression caused by alcohol, which can lead to autoinfection and dissemination. The aim of this study was to evaluate multiple stool sampling and a specific parasitological assay agar plate culture (APC) for the diagnosis of Strongyloides stercoralis in alcoholics. APC was compared to sedimentation technique (HPJ; Hoffman, Pons and Janer), as parasitological methods to detect S. stercoralis infection in alcoholic individuals. Three stool samples from 60 alcoholic and 60 non-alcoholic individuals were analyzed. S. stercoralis larvae were observed in 11 (18.3%) alcoholic individuals and 1 (1.7%) nonalcoholic individual (P = 0.0042). In view of the combined results, sensitivity for the APC method was 63.6% (CI 31.6-87.6%) with the first sample reaching 100% (CI 67.8-100%) after analyzing three fecal samples. The HPJ sensitivity was 36.4% (CI 12.4-68.4) in the first sample, reaching 72.7% (CI 39.3-92.7) after three samples analyzed. The present results suggest that in alcoholic patients, it is important to repeat stool sampling with specific techniques, especially using the APC method, to avoid misdiagnosis in cases that could evolve to disseminated strongyloidiasis.

Influence of Training and Development on Affective Commitment among Academic Staff of Public Universities in Lagos, Nigeria

Many Nigerian public universities are bedeviled with diverse challenges ranging from inadequate condition of work, human resource capacity and retaining skilled academic staff. This has overtime had debilitating consequences on the ability of these institutions to make giant strides especially from the purview of political and socio-economic developments. These attendant challenges have created reasons as to why the Nigerian tertiary institutions are experiencing continuous dearth of skilled teaching personnel and as a result, the quest for skilled academic personnel continues to rise. Based on these arguments, this study examined the influence of training and development as an employee retention strategy on affective commitment among academic staff of public universities in Lagos State, Nigeria. The population comprised 3354 academic staff from University of Lagos, Akoka-Yaba, National Open University of Nigeria, Victoria-Island, Lagos State University, Ojo, Lagos State University of Science and Technology, Ikorodu and Lagos State University of Education, Ijanikin. Through a multiple sampling technique, a total of 450 respondents served as the sample size for the study. Data were analysed using both descriptive, as well as inferential statistics. Findings revealed that a positive and significant relationship exist between training and development and affective commitment with (r=0.941, p-value<0.05). The study concluded that for academic staff of public universities to remain committed, management of public universities must fashion out modalities and framework for blending training and development, towards enhancing the commitment of academic staff in Nigerian public universities.

NEXMD v2.0 Software Package for Nonadiabatic Excited State Molecular Dynamics Simulations.

We present NEXMD version 2.0, the second release of the NEXMD (Nonadiabatic EXcited-state Molecular Dynamics) software package. Across a variety of new features, NEXMD v2.0 incorporates new implementations of two hybrid quantum-classical dynamics methods, namely, Ehrenfest dynamics (EHR) and the Ab-Initio Multiple Cloning sampling technique for Multiconfigurational Ehrenfest quantum dynamics (MCE-AIMC or simply AIMC), which are alternative options to the previously implemented trajectory surface hopping (TSH) method. To illustrate these methodologies, we outline a direct comparison of these three hybrid quantum-classical dynamics methods as implemented in the same NEXMD framework, discussing their weaknesses and strengths, using the modeled photodynamics of a polyphenylene ethylene dendrimer building block as a representative example. We also describe the expanded normal-mode analysis and constraints for both the ground and excited states, newly implemented in the NEXMD v2.0 framework, which allow for a deeper analysis of the main vibrational motions involved in vibronic dynamics. Overall, NEXMD v2.0 expands the range of applications of NEXMD to a larger variety of multichromophore organic molecules and photophysical processes involving quantum coherences and persistent couplings between electronic excited states and nuclear velocity.

A 1/f noise optimized correlated multiple sampling technique for complementary metal oxide semiconductor image sensor

SummaryCorrelated multiple sampling (CMS) technique is often used to reduce random noise in complementary metal oxide semiconductor (CMOS) image sensor, but as the number of samples increases, the suppression of 1/f noise by standard CMS based on averaging sampling gradually decreases. Therefore, in this paper, a 1/f noise optimized correlated multiple sampling (NOCMS) technique based on differentiated sampling weights is proposed. Transfer functions of standard CMS and NOCMS for analyzing the suppression effect of random noise respectively are derived based on the Fourier transform theory. And NOCMS shows a dramatic advantage in the suppression of 1/f noise. In addition, a circuit structure based on single‐slope analog‐to‐digital converter (SSADC) for implementing NOCMS is suggested. Ramp generator provides multiple sets of ramps with different slopes to quantify the reset and signal voltages of pixel output. Sampling weights are increased with the decrease of ramp slopes. The last reset and first signal values are weighted more due to their potentially higher correlations which highlights the principle of assigning weights. Simulation results under 110 nm CMOS technology illustrate that the input‐referred random noise is 142.9 V under standard CMS and 120.9 V under NOCMS when the number of samples equals 8. The noise reduction effect is improved by 15%. NOCMS makes it possible to further reduce 1/f noise of CMOS image sensor.

Generic Strategies: A driver for Firms Competitiveness in Nigerian Fast Moving Consumers Goods (FMCGs) Sector

Competitiveness has become one of the objectives of firms in today’s world especially in consumer goods sector. Every firm wants to have a reasonable share in the market to achieve specific firm goals which competitiveness is part of. To achieve this objective, consumers goods firms need to adopt appropriate strategies. Thus, the need to see how Porter generic strategies could drive competitiveness strength of Fast Moving Consumer Goods (FCMB) in Nigeria. The study employed survey research design and primary source of data collection via questionnaire as well as multiple sampling techniques (simple and stratified). Simple regression was utilized as data analytical tool and it was found that differentiation and focus strategies have significant effect on FMCGs firms competitiveness. The study concluded that generic strategies (differentiation and focus) are determinants for firms competitiveness in FMCGs sector. It was therefore recommended that FMCGs firms should continue to deploy differentiation and focus strategies to achieve their competitive objectives.

Analisis faktor-faktor yang mempengaruhi tingkat keberdayaan perempuan

This study aims to analyze the factors that influence the level of women's empowerment. The method used is survey research with a quantitative verification approach. The research was conducted in Indramayu Regency, using the Multiple Stage Sampling technique. Five (5) sub-districts were taken from 31 sub-districts, and 20 respondents were randomly selected from each sub-district so that the total number was 100 women respondents. Individual characteristics, competence, and availability of information are exogenous variables while the endogenous variable is the level of women's power. Analysis using Structural Equation Modeling (SEM), with calculations assisted by Smart PLS 4 software. The validity test was carried out to see valid indicators based on the loading factor value > 0.5, the reliability test was carried out on the research variables, and the SEM model was obtained in iteration 2. The results showed that individual characteristic variables, competence, and information availability contributed 61% to women's empowerment level. Individual characteristics have a positive effect of 0.77 and are significant on the level of women's empowerment. Women's competence needs to be increased, as well as the availability of information so that women can play an active role and increase their involvement in the economy and development.

Grill workers and air pollution health effects from charcoal combustion in Vientiane capital

Introduction: Grilled street foods are popular in urban communities in Lao People's Democratic Republic (Lao PDR). Charcoal is the main fuel used for, posing a risk of elevated exposure to toxic pollutants. This study explored levels of cooking-related pollutants from grilled food business and workers’ health effects.
 Materials and methods: A quantitative approach using multiple techniques was conducted during March and April 2022 in Vientiane Capital, Lao PDR. Methods included pollutant emission estimation from charcoal-combusting grill shops/street-carts and Particulate Matter (PM2.5) measurement, and examined the exposure and health effects among grill workers. Multiple sampling techniques were applied to identify study samples. Respiratory symptoms were the health effect of interest among grill workers.
 Results: Estimated emission of pollutants was over 75 tons/year from grill shops. Average PM 2.5 level was 84.8 μg/m3 (21.6 - 254.8 μg/m3); which i above standard limits. A very high level of PM2.5 was found in grill markets. Most grill workers were female, worked 6-7 days/week, at least 8 h/day. Factors contributing to the presence of respiratory symptoms among grill workers were female gender, low income, indoor grilling, more years of grill-work, experience of intense smoke-cough, self-reliance on health and cigarette smoking.
 Conclusion: Grilling contributes to ambient air pollution, posing potential adverse environmental and public health impacts. Grill workers are likely to be exposed to high levels of all forms of air pollutants from street food grilling. Effective strategies are required to better protect grill workers from the effect of exposure to these harmful toxins and minimize the negative impacts on their health.