PHYSICAL AND ENGINEERING PROPERTIES OF PEAT SOIL STABILIZED WITH THE ADMIXTURE OF CACO3+RICE HUSK ASH DUE TO WATER INFILTRATION FROM SURROUNDING AREAS

Peat is a type of soil with high organic content, very low bearing capacity, and high uneven settlement. Some methods to improve soil have been applied to peat in order to make it strong enough for civilization-building foundation situated on it. Peat stabilization is a method that is continuously developed considering that the cost it needs is lower and this approach is more environmentally friendly compared to other methods. The admixture of lime (CaCO3) and Rice husk ash, a new ecofriendly stabilizer material, has been applied to peat soil and showed a good result. However, in studies conducted previously, the effect of water infiltration from surrounding areas of soil was stabilized was not involved as variable influencing the change of parameter. Based on that, this laboratory study was carried out to model the real condition in the field when the stabilization is performed and to identify the physical and engineering changes of peat soil in the 10th, 20th, and 30th days of stabilization in its border and middle parts, with the percentage of material stabilizer 5%, 10%, 15% and 20% of the unit weight of the initial condition of peat. The result of laboratory test shows that the addition of admixture of lime (CaCO3) and rice husk ash can improve the physical and engineering properties of peat soil are stabilized. Water infiltration occurred on peat soil is stabilized has not affected the physical and engineering properties of the soil. It can be seen from the physical and engineering properties of the border and central parts of peat soil is stabilized that still have a similar value. It is assumed to be caused by CaSiO3 gel formed still needs a longer duration to become stable gel. However, in this initial study it was known that the more stabilizers added, made the better the parameters of the stabilized peat soil.

Changeability and agility enablers in one-of-a-kind product development and design processes

The smart factories that are already beginning to appear employ a completely new approach to product creation. Smart products are uniquely identifiable and know both their current status and alternative routes to achieving their target state. Smart factories allow individual customer requirements to be met, meaning that even one-off items can be manufactured profitably. In smart industry, dynamic business and engineering processes enable last-minute changes to design and production, delivering the ability to respond flexibly to disruptions and failures on behalf of suppliers. This paper presents a case study of product development and design process renovation according to changeability paradigm in one-of-a-kind industrial environment. It demonstrates how integration of changeability with agile design strategies crucially contribute to improve the operations of a highly individualized product development business. Successful management of ‘never-ending’ engineering changes appears to be the most important aspect in this field. Contribution of the presented work is a generalized framework that demonstrates how companies in such specific environments can improve competitiveness through the utilization of changeability concepts. The included case study validated the proposed changeability model and offers valuable insights into how to implement this in practice.

A Topic Modeling Approach to Study Design Requirements

Risk management is vital to a product’s lifecycle. The current practice of reducing risks relies on domain experts or management tools to identify unexpected engineering changes, where such approaches are prone to human errors and laborious operations. However, this study presents a framework to contribute to requirements management by implementing a generative probabilistic model, the supervised latent Dirichlet allocation (LDA) with collapsed Gibbs sampling (CGS), to study the topic composition within three unlabeled and unstructured industrial requirements documents. As finding the preferred number of topics remains an open-ended question, a case study estimates an appropriate number of topics to represent each requirements document based on both perplexity and coherence values. Using human evaluations and interpretable visualizations, the result demonstrates the different level of design details by varying the number of topics. Further, a relevance measurement provides the flexibility to improve the quality of topics. Designers can increase design efficiency by understanding, organizing, and analyzing high-volume requirements documents in confirmation management based on topics across different domains. With domain knowledge and purposeful interpretation of topics, designers can make informed decisions on product evolution and mitigate the risks of unexpected engineering changes.

COVID-19 disaster management plans for two laboratory animal facilities in South Africa

Policies and guidelines are available for acute disasters such as earthquakes, fire and floods, however, little is available on how laboratory animal facilities should mitigate subacute disasters like the COVID-19 pandemic that imposed major restrictions on the free movement of people. As such, laboratory animal facilities had to find plausible mitigating measures to safeguard the welfare of animals in their care, to prevent animal suffering if staff could not reach the animals, albeit with limited time. The simplest approach was to stop active experiments and halt animal breeding, or to euthanize all animals. Challenges with such methods included the ethical debate regarding euthanasia of animals at the start of a pandemic and the need to perform a harm–benefit analysis while drafting the disaster plans, termination of studies at advanced stages with information loss or killing of genetically modified strains that would be difficult to replace. Two research animal facilities in South Africa addressed these challenges by implementing several changes such as allowing only essential studies to continue, maintaining small breeding colonies for essential strains, and providing staff with private transport for travelling to and from work to avoid public transport and risk of exposure to SARS-CoV-2. Engineering changes included redesigning working areas to cater for social distancing. The mitigating measures put in place by the two laboratory animal facilities were successful in ensuring the continued welfare of animals during the COVID-19 lockdown restrictions. These measures can be adopted in future pandemics that lead to restricted movement of staff. Plans de gestion en cas de catastrophes telles que le COVID-19 pour deux installations d’animaux de laboratoire en Afrique du Sud

Change impact analysis of complex product based on three-parameter interval grey number grey relational model

Change impact evaluation of complex product plays an important role in controlling change cost and improving change efficiency of engineering change enterprises. In order to improve the accuracy of change impact evaluation,this paper firstly expresses engineering changes based on multi-stage complex networks. Then, it constructs the evaluation index system of complex product engineering change impact. Next, based on the combination weighted three-parameter grey relational model, the engineering change impact of complex product is evaluated. Finally, a case analysis was carried out with the permanent magnet synchronous centrifugal compressor in a large permanent magnet synchronous centrifugal unit to verify the effectiveness of the proposed method.

Zeitpunktabhängige Prognose von Änderungsaufwänden/Time-dependent prediction of effort needed for engineering changes

Der Beitrag stellt eine Methode zur Prognose des Änderungsaufwands in der Fertigung eines sich noch in der Entwicklung befindlichen Bauteils vor. Der Änderungsaufwand wird definiert über die Umsetzungsdauer und die Änderungskosten. Im Unterschied zu bestehenden Methoden, die Änderungen bewerten, erlaubt diese Methode den Änderungsaufwand zu beliebigen Zeitpunkten im Produktentstehungsprozess zu prognostizieren. Je nach zeitlicher Distanz zum Produktionsstart variiert der Änderungsaufwand. Die speziell für die Automobilindustrie entwickelte Methode liefert eine Entscheidungsgrundlage, um die Änderungsflexibilität zu erhöhen.   This paper presents an approach for predicting change efforts for planning the production of a component under development. The change effort is characterized by the duration of implementation and the respective costs. Unlike existing methods for change impact analyses, this method enables an automated change impact prediction at any point in time within the product development process, since change impact differs with temporal distance to the start of production. The method was developed for the automotive industry and delivers a valid basis for increasing flexibility with a view to production system changes.