I takt med att sociala medier har växt sig större har konsumenters shoppingbeteende förändrats. Inköp av produkter sker numera i allt större utsträckning på sociala medier. Den senaste plattformen TikTok har påskyndat förändringen av informationssökning med sitt korta videoformat som låter användare dela information om produkter samtidigt som de har roligt. Studiens syfte är att undersöka hur TikTok som plattform används vid informationssökning och hur konsumenterna påverkar varandra vid användandet av TikTok. Kvalitativa semistrukturerade intervjuer har genomförts för att samla in material för att besvara studiens syfte. Fem teman kring konsumenters upplevelse av TikTok har identifierats genom en tematisk analys. Teorierna electronic word-of-mouth (eWOM) och flow har använts för att analysera de fem temana. Resultatet visar att TikTok är en källa till inspiration som kan leda till konsumtion och nöje. På TikTok skapas en ny form av communities som är löst sammansatta till skillnad från communities som har varit slutna på andra sociala plattformar. Flow är en betydande del av den underhållande upplevelsen och engagemanget på TikTok men studien visar också att flow kan leda till negativa effekter. Studien har ett begränsat omfång på grund av urval av respondenter men kan användas som grund för vidare forskningen kring flow och communities på TikTok då den visar att detta påverkar konsumenters informationssökning. / As social media has grown in popularity, consumers’ shopping behaviour has changed. The purchase of products is now increasingly done on social media. The latest platform TikTok has accelerated the change in information seeking with its short video format that allows users to share information about products while having fun. The purpose of the study is to investigate how TikTok as a platform is used when searching for information and how consumers influence each other when using TikTok. Qualitative semi-structured interviews have been conducted to collect material to answer the study's purpose. Five themes surrounding consumers' experience of TikTok have been identified through a thematic analysis. The theories electronic word-of-mouth (eWOM) and flow have been used to analyse the five themes. The result shows that TikTok is a source of inspiration that can lead to consumption and enjoyment. TikTok has formed a new form of communities that are loosely composed, unlike closed communities on other social platforms. Flow is a significant part of the joyful experience and engagement on TikTok, but the study also shows that flow can lead to negative effects. The study has a limited scope due to the selection of respondents, but can be used as a basis for further research on flow and communities on TikTok as it shows that this affects consumers' information search. This study will be written in swedish.

<p> In this thesis, we have considered the vehicle routing problem with pickup and delivery which is a generalization of the capacitated vehicle routing problem (CVRP). The vehicle routing problem with pickup and delivery (VRPPD) arises whenever pickup demand and delivery demand is to be satisfied by the same vehicle. The problem is encountered in many real life situations including reverse logistics. We consider three variants of VRPPD, namely, the vehicle routing problem with back-hauls (VRPB), the vehicle routing problem with back-hauls and mixed-load (VRPBM) and the vehicle routing problem with simultaneous pickup and delivery (VRPSPD). </p> <p> The inherent complexity of VRPPD makes it an NP -hard problem. It is not possible to solve an NP-hard problem in polynomial time unless P = NP. Therefore, heuristics and metaheuristics are used to produce a good quality solution within reasonable CPU time. We develop ant colony algorithms for VRPB, VRPBM and VRPSPD. We have improved the existing ant-colony algorithms by applying better local search schemes and by adding new features such as construction rule and the trail updating criteria. We also develop saving based heuristics for single and multi-depot versions of VRPSPD. Checking feasibility of a given route is an important issue in VRPSPD because of the fluctuating load on the vehicle. We have proposed the cumulative net-pickup approach for this purpose. One important feature of this approach is that it checks the feasibility of an altered route in constant time. </p> <p> The proposed heuristics and metaheuristics are evaluated by solving benchmark problem instances available in literature and then comparing the solutions with the solutions produced by the existing algorithms. Our computational experiment has shown that the proposed heuristics and metaheuristics give better or equally good results in comparison to the existing solution procedures. </p> / Thesis / Doctor of Philosophy (PhD)