Light scattering is a fundamental property that can be exploited to create essential devices such as particle analysers. The most common particle size analyser relies on measuring the angle-dependent diffracted light from a sample illuminated by a laser beam. Compared to other non-light-based counterparts, such a laser diffraction scheme offers precision, but it does so at the expense of size, complexity and cost. In this paper, we introduce the concept of a new particle size analyser in a collimated beam configuration using a consumer electronic camera and machine learning. The key novelty is a small form factor angular spatial filter that allows for the collection of light scattered by the particles up to predefined discrete angles. The filter is combined with a light-emitting diode and a complementary metal-oxide-semiconductor image sensor array to acquire angularly resolved scattering images. From these images, a machine learning model predicts the volume median diameter of the particles. To validate the proposed device, glass beads with diameters ranging from 13 to 125 µm were measured in suspension at several concentrations. We were able to correct for multiple scattering effects and predict the particle size with mean absolute percentage errors of 5.09% and 2.5% for the cases without and with concentration as an input parameter, respectively. When only spherical particles were analysed, the former error was significantly reduced (0.72%). Given that it is compact (on the order of ten cm) and built with low-cost consumer electronics, the newly designed particle size analyser has significant potential for use outside a standard laboratory, for example, in online and in-line industrial process monitoring.
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When reconstructing a shooting incident with a shotgun, the muzzle-to-target distance can be determined by relating the size of a dispersion pattern found on a crime scene to that of test shots. Ideally, the test shots are performed with the weapon and ammunition that were used in the incident. But sometimes examiners will have to resort to alternatives, such as using cartridges of the same brand and type but with another pellet size. For this reason, the relationship between pellet size and shotgun dispersion patterns was studied with both lead and steel shotgun pellets. Cartridges were loaded with identical cartridge cases, powder charges, and wads but with different pellet sizes, below size B. The cartridges were fired, and the dispersion patterns at 5 m in front of the muzzle were measured and compared. The results provide strong support for the proposition that shotgun dispersion patterns with both lead and steel shot increase with decreasing pellet size if all other relevant parameters are kept equal. The results also provide an indicative measure of the magnitude of the effect. Pattern sizes were approximately 1.7 times larger with #9 than with #0 lead shot and 1.4 times larger with #9 than with #1 steel shot. The differences between consecutive shot sizes were generally smaller. This means that cartridges of equal brand and type but with the next nearest shot number can be used for a muzzle-to-target distance determination, keeping the information of the current study in mind in the final interpretation of the results.
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OBJECTIVE: This work aims to gain insight into the long-term impact of depression course on social network size and perceived loneliness in older people living in the community. METHODS: Within a large representative sample of older people in the community (Longitudinal Aging Study Amsterdam (LASA)), participants with clinically relevant levels of depressive symptoms (scores >16 on the Center for Epidemiological Studies Depression Scale) were followed up over a period of 13 years of the LASA study (five waves). General estimating equations were used to estimate the impact of depression course on network size and loneliness and the interaction with gender and age. RESULTS: An unfavorable course of depression was found to be associated with smaller network sizes and higher levels of loneliness over time, especially in men and older participants. CONCLUSIONS: The findings of this study stress the importance of clinical attention to the negative consequences of chronicity in depressed older people. Clinicians should assess possible erosion of the social network over time and be aware of increased feelings of loneliness in this patient group.
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This study is the first to estimate the size of the informal tourism economy. Using a dynamic general equilibrium model, this paper first estimates the size of the informal tourism economy and then assesses its linkages to key labour market variables in Thailand. Empirical results indicate that: (a) the informal tourism economy grows faster than the formal tourism and aggregate economy; (b) both formal and informal tourism economies absorb the unemployed; (c) the relationship between formal and informal economies is negative in the aggregate but positive in the tourism sector.
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Het hbo kampt met gering studiesucces van studenten in termen van studievoortgang, uitval en gepercipieerde competentie. Welke maatregelen kan het hbo nemen? Deze bijdrage, gebaseerd op het proefschrift ‘One size fits all?’, gaat over leerpsychologische factoren en interactionalistische factoren waaruit studiesucces in het eerste jaar hbo kan worden verklaard. Het proefschrift laat zien hoe vele variabelen samenhangen met studiesucces. Met behulp van lineair structurele modellen doet de auteur voorzichtige uitspraken over de effecten die factoren op elkaar en op studiesucces (uitval, studievoortgang en gepercipieerde competentie) hebben. Van de leerpsychologische factoren hadden zelfvertrouwen en motivatie-aspecten (intrinsieke motivatie en procrastinatie) de sterkste samenhang met studiesucces. Vanuit interactionalistisch perspectief was intentie om te blijven de meest cruciale factor. De samenhangen met studiesucces van andere factoren uit beide benaderingen waren gering (diepgaand leren) of fluctueerden sterk per model en per groep (zelfregulatie, self-efficacy; sociale en academische integratie tevredenheid met actief leren en academische kennis en vaardigheden, contacturen, zelfstudie). Vele factoren spelen een rol, die bovendien naar achtergrondkenmerken (geslacht, vooropleiding, etniciteit, discipline) verschillend met elkaar samenhangen. Ook hebben verschillende factoren niet dezelfde, maar eerder tegenstrijdige effecten op concurrerende leeruitkomsten, zoals het behalen van credits en het verwerven van competentie. Het resultaat is niet een kookboek met pasklare recepten voor het oplossen van het rendementsprobleem. Voor de onderwijspraktijk (instellingen, opleidingen, docenten) zijn dat belangrijke inzichten waarmee meer gedaan kan worden. Meer onderzoek blijft gewenst naar de interactie tussen factoren uit verschillende verklaringsmodellen en -theorieën naar de effecten van rendementsmaatregelen.
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Studying animal grouping behavior is important for understanding the causes and consequences of sociality and has implications for conservation. Chimpanzee (Pan troglodytes) party size is often assessed by counting individuals or extracted indirectly from camera trap footage or the number of nests. Little is known, however, about consistency across methods for estimating party size. We collected party size data for wild chimpanzees in the Issa valley, western Tanzania, using direct observations, camera traps, and nest counts over six years (2012–2018).
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Pitch size varies in official soccer matches and differently sized pitches are adopted for tactical purposes in small-sided training games. Since interactive team behaviour emerges under constraints, the authors evaluate the effect of pitch size (task) manipulations on interactive team behaviour in small-sided soccer games. Four 4-a-side (plus goalkeepers) small-sided games were played: a reference game (30×20 m), length manipulation (24×20 m), width manipulation (30×16 m), and a combination (24×16 m). Using position data (100Hz), three measures quantifying the teams' interaction were calculated: longitudinal inter-team distance, lateral inter-team distance, and surface area difference. Means and standard deviations, correlations and coupling values were calculated. Running correlations were calculated over a 3-s window to evaluate interaction patterns. As expected, a shorter pitch results in smaller longitudinal inter-team distance, lateral inter-team distance decreased for narrow pitches, and smaller total playing area resulted in decreased surface area. Unanticipated, a crossover effect was present; length and width manipulations also triggered changes in lateral and longitudinal direction respectively. Inter-team distances and surface area difference differed significantly across conditions. Interaction patterns differed across conditions for all measures. So, highly tactically relevant, soccer teams seem to adapt their interactive behaviour according to pitch size in small-sided games. © 2013 Institute of Systems Science, Academy of Mathematics and Systems Science, CAS and Springer-Verlag Berlin Heidelberg.
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BACKGROUND: Total body surface area (TBSA) burned, expressed as percentage is one of the most important aspects of the initial care of a burn victim. It determines whether transfer to a burn centre is necessary as well as the need for, and amount of, intravenous fluid resuscitation. Numerous studies, however, have highlighted inaccuracies in TBSA assessment. Therefore, the differences in burn size estimates between referrers and burn centre's in children and its consequences in terms of transfer and intravenous fluid resuscitation were investigated.METHODS: This study involved two time periods from January 2002 until March 2004 and January 2007 until August 2008. All referred children admitted to a Dutch Burn centre within 24h post burn were eligible. Data were obtained from patient records retrospectively and in part prospectively.RESULTS: A total of 323 and 299 children were included in periods 1 and 2, respectively. Referring physicians overestimated burn size with a factor two (mean difference: 6% TBSA ± 5.5). About one in five children was referred to a burn centre without fulfilling the criteria for referral with regard to burn size (assessed by burn specialists) special localisation or inhalation trauma. Proportions of children receiving intravenous fluid resuscitation regardless of indication increased from 33% to 49% (p<0.01). The received volumes tended to be higher than necessary.CONCLUSIONS: Referring physicians overestimate burn size in children admitted to Dutch burn centres. This has little negative consequences, however, in terms of unindicated transfers to a burn centre or unnecessary fluid resuscitation.
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Middelgrote steden zijn gedurende de 20e eeuw vaak aangepakt met een metropolitaan instrumentarium. Vraag is wat er gebeurt als we steden, regio's en zelfs metropolen benaderen vanuit een middelgrootstedelijk perspectief.
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Distribution centres are becoming more and more relevant for spatial planning, due to their rapidly increasing size and number. There is little literature, however, that provides a generalized analysis of the size and functional attributes of distribution centres, and none that discusses the relationships between these attributes. Our aim is to fill this gap by providing new evidence and analysis to understand this relationship. We make use of an extensive database of 2888 DCs in the Netherlands to develop a new typology of DCs based on the geographical location of DCs, their functional attributes and client sector characteristics. The analysis shows that the context in which medium sized DCs are operating is more heterogeneous than in the case of very large and small size DCs. This study is a first attempt to analyse this relationship between facility size and functions based on a rich and extensive dataset of large population of DCs. The results can serve as input for further quantitative statistical analysis and international comparison.
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