Vertical takeoff and landing (VTOL) drones are increasingly recognized as an important solution for last-mile delivery in the food and beverage sector, owing to their rapid deployment capabilities and high operational flexibility. In particular, growing interest in drone delivery services has been observed among fast food and coffee franchises, where rapid delivery is essential due to the time-sensitive nature of food and beverage items intended for immediate consumption. Despite this trend, there remains a lack of research on the structural modeling of flight routes for VTOL drones operating under automatic flight conditions, and on the implementation of first-come-first-served (FCFS) delivery services utilizing predefined flight routes. Accordingly, this study comprehensively describes the operations for food and beverage delivery services using VTOL drones. In particular, it addressed the use of multiple drones to conduct FCFS-type multi-point delivery services along fixed routes suitable for automatic flight.

본 연구는 저관리형 거리화단 화훼경관용 초화류 식물 선발을 위하여, 4종의 초본화훼식물(Zinnia elegans, Salvia splendens, Catharanthus roseus, Gomphrena globose )을 대상으로 무관 수 처리에 따른 내건성을 구명하고자 실시하였다. 4종 식물의 영구위조점을 알아본 결과, 무관수 후 백일초가 23일째 가장 먼저 고사하였고, 그 다음으로 살비아는 29일째, 일일초는 51일 째, 천일홍은 61일째에 고사하였다. 무관수 처리에 따른 4종의 용적수분함량 변화를 비교한 결과, 용적수분함량은 무관수 이후 지속적으로 감소하였고, 용적수분함량이 0%에 도달한 것은 백 일초가 무관수 16일째로 가장 빨랐으며, 그 다음으로 살비아 25일, 일일초 35일, 천일홍 40일 순으로 나타났다. 4종의 지상 부생체중의 감소율을 영구위조점에서 보았을 때 4종의 식물중 백일초의 감소율이 가장 높았고, 그 다음은 살비아, 천일홍, 일일초 순으로 높게 나타났다. 또한 지상부와 지하부 건물중의 증가율은 일일초가 가장 높았으며 통계적으로 유의하였다. 무관 수 처리에 따른 광합성 형광 변수 중 하나인 Fv/Fm 측정 결과, 백일초는 일시위조점인 15일째부터 감소하였고, 살비아는 무관 수 29일째, 일일초는 37일째, 천일홍은 43일째부터 감소하였 으며, 통계적으로 유의하였다. 무관수 처리에 따른 4종의 각 개체별 측정된 식생지수의 변화를 알아본 결과, 정규식생지수 (normalized difference vegetation index, NDVI), 광화학 반사율 지수(photochemical reflectance index, PRI), 안토 시아닌 반사율 지수(anthocyanin Reflectance Index, ARI) 가 무관수 기간동안 백일초, 살비아보다 일일초, 천일홍이 장기 간 건강한 잎의 범위에 속하였다. 본 연구결과를 종합해 볼 때, 저관리형 거리화단 화훼경관용 식물 선정 시 거리화단의 수분관 리 측면을 고려한다면 무관수 처리 후 약 50-60여 일간 생존하 여 내건성이 강한 것으로 나타난 일일초, 천일홍이 저관리형 거리화단 화훼경관 조성 시 적용 가능성이 매우 높은 식물로 판단되었다. 거리화단 화훼경관 조성 후 물관리가 어려운 거리 화단 화훼경관의 지속적인 유지, 관리에 대한 어려움이 부각되 어왔다. 따라서 저관리형 거리화단 화훼경관용 식물의 다양한 적용 및 관리를 위해서는 향후 보다 많은 식물종을 대상으로 한 실험뿐만 아니라 식물 내에서 품종 간의 비교에 대한 후속 연구도 필요한 것으로 생각되었다.

Background: With the increase of seated work, interest in forward head posture (FHP) has grown. Prolonged computer tasks with FHP have been considered a factor that increases the stiffness and tone of the upper trapezius (UT) muscle. Traditionally, many studies have measured the craniovertebral angle (CVA) in standing positions to assess FHP, making it difficult to determine whether the CVA measured in a habitual working posture correlates with the stiffness and tone of the UT muscle in office workers. Objects: This study aimed to investigate the relationship among CVA, UT muscle stiffness, and tone in both habitual working and standing postures among asymptomatic office workers. Methods: Forty asymptomatic office workers participated in the study. CVA was measured in both habitual working and standing postures. Stiffness and tone of the UT muscle were assessed after a 10-minute computer task. Pearson’s correlation coefficient was used to investigate the relationship between CVA and stiffness and tone of the UT muscle. Results: No significant correlations were found between CVA in standing posture and the stiffness and tone of the UT muscle. However, moderate negative correlations were observed between CVA measured in the habitual working posture and both the stiffness (dominant: r = –0.490, non-dominant r = –0.465) and tone (dominant: r = –0.501, non-dominant r = –0.446) of the UT muscle. Conclusion: This study highlights that decreased CVA in habitual working posture is associated with increased stiffness and tone of the UT muscle in asymptomatic office workers. Therefore, measuring CVA in the habitual working posture should be considered when evaluating stiffness and tone of the UT muscle.

Background: Chronic low back pain (CLBP) is a common health problem among female caregivers. In Korea, 70.4% of caregivers experience LBP after caregiving. The prevalence of LBP was higher in female caregivers of patients who required physical assistance with transfer than in those caring for patients who did not require physical assistance. Lifting movements, such as patient transfer and positioning, are associated with lumbopelvic stability (LPS) and knee muscle strength. However, no studies have investigated the differences in LPS and knee muscle strength between female caregivers with and without CLBP. Objects: This study was conducted to investigate the differences of the LPS, knee extension strength (KES) and knee flexion strength (KFS) between female caregivers with and without CLBP. Methods: Thirty-one female caregivers participated in this study. Participants were divided into two groups: (1) caregivers without CLBP (n = 13) and (2) caregivers with CLBP (n = 18). LPS, KES, and KFS levels were measured. An independent t-test was used to compare the LPS, KES, and KFS between caregivers with and without CLBP. The statistical significance was set at α of 0.05. Results: The LPS and KES scores were significantly lower in caregivers with CLBP than those without. In contrast, the KFS did not differ significantly between the groups. Conclusion: This study observed associations of both LPS and KES with CLBP among female caregivers.