In this paper, we introduce two algorithms to address the two-echelon capacitated location-routing problem (2E-CLRP). We introduce a branch-and-cut algorithm based on the solution of a new two-index vehicle-flow formulation, which is strengthened with several families of valid inequalities. We also propose an adaptive large-neighbourhood search (ALNS) meta-heuristic with the objective of finding good-quality solutions quickly. The computational results on a large set of instances from the literature show that the ALNS outperforms existing heuristics. Furthermore, the branch-and-cut method provides tight lower bounds and is able to solve small- and medium-size instances to optimality within reasonable computing times.

Optimizing supply chain is the most successful key for manufacturing systems to be competitive. Supply chain (SC) has gotten intensive research works at all levels: strategic, tactical, and operational levels. These levels, in some researches, have integrated with each other or integrated with other planning issues such as inventory. Optimizing inventory location and level of safety stock at all supply chain partners is essential in high competitive markets to manage uncertain demand and service level. Many works have been developed to optimize the location of safety stock along supply chain, which is important for fast response to fluctuation in demand. However, most of these studies focus on the design stage of a supply chain. Because demand at different horizon times may vary according to different reasons such as the entry of different competitors on market or seasonal demand, safety stock should be optimized accordingly. At the planning (tactical) level, safety stock can be controlled according to each planning horizon to satisfy customer demand at lower cost instead of being fixed by a decision taken at the strategic level. On the other hand, most studies that consider safety stock optimization are tied to a specific system structure such as serial, assembly, or distribution structure. This research focuses on formulating two different models. First, a multi- echelon safety stock optimization (MESSO) model for general supply chain topology is formulated. Then, it is converted into a robust form (RMESSO) which considers all possible fluctuation in demand and gives a solution that is valid under any circumstances. Second, the safety stock optimization model is integrated with tactical supply chain planning (SCP) for manufacturing systems. The integrated model is a multi-objective mixed integer non-linear programming (MINLP) model. This model aims to minimize the total cost and total time. A case study for each model is provided and the numerical results are analyzed.

In this paper,we propose an adaptive large neighborhood search heuristic for the Two-Echelon Vehicle Routing Problem (2E-VRP) and the Location Routing Problem (LRP).The 2E-VRP arises in two-level transportation systems such as those encountered in the context of city logistics. In such systems, freight arrives at a major terminal and is shipped through intermediate satellite facilities to the final customers. The LRP can be seen as a special case of the 2E-VRP in which vehicle routing is performed only at the second level. We have developed new neighborhood search operators by exploiting the structure of the two problem classes considered and have also adapted existing operators from the literature. The operators are used in a hierarchical scheme reflecting the multi-level nature of the problem. Computational experiments conducted on several sets of instances from the literature show that our algorithm out performs existing solution methods for the 2E-VRP and achieves excellent results on the LRP.

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / The present research seeks to show the importance of applying process management techniques and food safety norms in the operational processes of the supply chain to know the meaning and the need for an integrated hybrid model. The article reviews the sugarcane distillery sector of Peru and its main operational problems. Based on the literature reviewed and discussed with academics who have knowledge of the food supply chain, an integrated hybrid model was developed to help any distillery with lower levels of competitiveness than its competitors in other sectors, such as pisco, applying techniques of process management and food safety to increase the efficiency of liquor distilleries. The findings confirm that distilleries can increase their efficiency, thanks to the higher performance of their operations after their alignment with the integrated model. / Revisión por pares

Background & problem:  In a fast-moving environment where organizations are forced to meet changing stakeholder needs, the importance of understanding top management teams (TMT) becomes more prominent given their influential position. Further on, with a growing population, the demand in the real estate industry is deemed to have a continuous growth. For this reason, the urge to implement a sustainability strategy has become fundamentally important to stay competitive. Hence, corporate sustainability communication has purposely been served as a tool to provide misleading information, commonly referred as greenwashing.   Purpose: Building on that, by studying the attitude of TMT regarding the integration of corporate sustainability strategies, it is possible to explore how TMTs are being influenced by stakeholders in their strategic decisions. Furthermore, it is possible to identify characteristics that affect potential drivers of greenwashing.    Method: To serve the purpose of this study, data were collected through a quantitative online survey targeting TMT members of Swedish real estate companies. The framework created for this study is based on an extensive literature review and contains constructs based on observable characteristics drawn on the illuminations from upper echelon theory (UET) (Hambrick & Mason, 1984). To adequately analyse relationships between the different variables, descriptive statistics, Pearson correlation analysis as well as multiple linear regression analysis were conducted.    Conclusion: The results show that the business career construct based on the UET items: financial position, different functional track, career experience and education, has a positive correlation with TMTs perceived gain of positive publicity by stakeholders if implementing a sustainability strategy. Moreover, this study adds knowledge of the underlaying characteristics of managers’ attitude towards corporate sustainability and provide support that business career characteristics follow a stakeholder-orientated logic of implementing a sustainability strategy.

Med bakgrund i tidigare forsknings tvetydiga resultat samt avsaknad av studier för svensk marknad ämnar denna studie undersöka huruvida styrelsens oberoende har ett samband med företagets finansiella prestation hos svenska börsnoterade företag. Urvalet baseras på bolag noterade på Nasdaq Stockholm Large-, Mid- och Small Cap samt Nordic Growth Market för åren 2014–2019 med totalt 478 observationer. Med hjälp av multipel regressionsmetod studerades styrelsens oberoende i förhållande till två prestationsmått, Return on Assets (ROA) och Tobins Q. Studien finner inget signifikant samband mellan styrelsens oberoende och företagets finansiella prestation oavsett vilket mått som används. Resultaten är robusta även för test över tidsperioden 2017–2019. Studiens resultat analyseras i relation till tidigare forskning samt agentteori och upper echelon theory. Utfallet för denna studie går inte i linje med teoriernas antaganden eller tidigare forskning i Europa, därav anses ytterligare studier krävas för att säkerställa sambandet.

Intresset för frivillig rapportering har under de senaste åren ökat. Tidigare studier har fått varierande resultat avseende vad som påverkar företags frivilliga rapportering, men managers personliga egenskaper har antagits kunna ha en påverkan. Syftet med studien är att förklara hur personliga egenskaper, som CEO:er respektive CFO:er i svenska börsnoterade företag besitter, påverkar den frivilliga rapporteringen i företagens årsredovisningar. Såväl påverkan på den totala mängden frivillig information som på vilka kategorier av frivillig information som läggs vikt vid studeras. Studien visade att kvinnliga CFO:er bidrar positivt till den totala mängden frivillig rapportering och att CFO:ers personliga egenskaper generellt har en större påverkan än CEO:ers personliga egenskaper på den frivilliga rapporteringen. Managers personliga egenskaper visades påverka den totala mängden frivillig rapportering mer än vilka kategorier som läggs vikt vid. Dock visade resultatet också på att agentteorin och de systemorienterade teorierna bättre förklarar vad som påverkar frivillig rapportering än vad managers personliga egenskaper gör. Studien bidrar till ökad kunskap om vad som påverkar företagens frivilliga rapportering. Genom att utgå från företagens CEO respektive CFO bidrar studien med förståelse för hur personliga egenskaper hos dessa påverkar den frivilliga rapporteringen, både den totala mängden och vilka kategorier av information som läggs vikt vid.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第19290号 / 工博第4087号 / 新制||工||1630(附属図書館) / 32292 / 京都大学大学院工学研究科都市社会工学専攻 / (主査)教授 谷口 栄一, 准教授 宇野 伸宏, 准教授 QURESHI,Ali Gul / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

Hållbarhet är ett ämne som de senaste åren blivit allt mer viktigt i samhället, där allt fler krav ställs på företag att ta sitt ansvar. Tidigare studier visar på ett positivt samband mellan andel kvinnor i styrelsen och hållbarhetsprestation. Forskning kopplat till åldersmässig mångfald och hållbarhetsprestation är däremot bristfällig och resultaten är varierande. Denna kvantitativa studie syftar till att undersöka om mångfalden i styrelsen har någon påverkan på CSR-prestationen i svenska börsnoterade bolag. Undersökningen genomförs med hjälp av en multipel regressionsmodell. För att mäta hållbarhetsprestation används Refinitivs ESG-poäng, vilket delas upp i tre olika faktorer: miljö, sociala och bolagsstyrning. Studiens resultat tyder på att det finns ett positivt signifikant samband mellan andelen kvinnor i styrelsen och hållbarhetsprestationen. Det återfinns inte någon signifikant betydelse för åldersmässig mångfald och hållbarhetsprestation, förutom en aspekt av ESG-poängen, bolagsstyrning, där det dokumenteras ett negativ samband. Slutligen återfinns inga fler signifikanta samband mellan åldersmässig mångfald och hållbarhetsprestation.

Yes / If a prosthetic foot creates resistance to forwards shank rotation as it deforms during loading, it will exert a braking effect on centre of mass progression. The present study determines whether the centre of mass braking effect exerted by an amputee's habitual rigid ‘ankle’ foot was reduced when they switched to using an ‘Echelon’ hydraulic ankle–foot device. Nineteen lower limb amputees (eight trans-femoral, eleven trans-tibial) walked overground using their habitual dynamic-response foot with rigid ‘ankle’ or ‘Echelon’ hydraulic ankle–foot device. Analysis determined changes in how the centre of mass was transferred onto and above the prosthetic-foot, freely chosen walking speed, and spatio-temporal parameters of gait. When using the hydraulic device both groups had a smoother/more rapid progression of the centre of pressure beneath the prosthetic hindfoot (p ≤ 0.001), and a smaller reduction in centre of mass velocity during prosthetic-stance (p < 0.001). As a result freely chosen walking speed was higher in both groups when using the device (p ≤ 0.005). In both groups stance and swing times and cadence were unaffected by foot condition whereas step length tended (p < 0.07) to increase bilaterally when using the hydraulic device. Effect size differences between foot types were comparable across groups. Use of a hydraulic ankle–foot device reduced the foot's braking effect for both amputee groups. Findings suggest that attenuation of the braking effect from the foot in early stance may be more important to prosthetic-foot function than its ability to return energy in late stance.