• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.12
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• pp.2218-2224
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• 2016

Opportunistic routing is designed for an environment where there is no stable end-to-end routing path between source node and destination node, and messages are forwarded via intermittent contacts between nodes and routed using a store-carry-forward mechanism. In this paper, we consider PRoPHET(Probabilistic Routing Protocol using History of Encounters and Transitivity) protocol as a base opportunistic routing protocol and propose an efficient context-aware opportunistic routing protocol by using the context information of delivery predictability and node type, e.g., pedestrian, car, and tram. In the proposed protocol, the node types of sending node and receiving node are checked. Then, if either sending node or receiving node is tram, messages are forwarded by comparing the delivery predictability of receiving node with predefined delivery predictability thresholds depending on the combination of sending node and receiving node types. Otherwise, messages are forwarded if the delivery predictability of receiving node is higher than that of sending node, as defined in PRoPHET protocol. Finally, we analyze the performance of the proposed protocol from the aspect of delivery ratio, overhead ratio, and delivery latency. Simulation results show that the proposed protocol has better delivery ratio, overhead ratio, and delivery latency than PRoPHET protocol in most of the considered simulation environments.

• Journal of Yeungnam Medical Science
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• v.35 no.1
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• pp.135-139
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• 2018

There has been a significant increase in the number of multiple pregnancies that are associated with a high risk of preterm delivery among Korean women. However, to date, delayed-interval delivery in women with multiple pregnancy is rare. We report a case of delayed-interval delivery performed 128 days after the vaginal delivery of the first fetus in a dichorionic diamniotic twin pregnancy. The patient presented with vaginal leakage of amniotic fluid at 16 weeks of gestation and was diagnosed with a preterm premature rupture of membranes. Three days later, the first twin was delivered, but the neonate died soon after. The second twin remained in utero, and we decided to retain the fetus in utero to reduce the morbidity and mortality associated with a preterm birth. The patient was managed with antibiotics and tocolytics. Cervical cerclage was not performed. The second twin was delivered vaginally at 34 weeks and 5 days of gestation, 128 days after the delivery of the first-born fetus. This neonate was healthy and showed normal development during the 1-year follow-up period. Based on our experience with this case, we propose that delayed-interval delivery may improve perinatal survival and decrease morbidity in the second neonate in highly selected cases.

• Journal of KIBIM
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• v.11 no.3
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• pp.55-66
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• 2021

Recently, Building Information Modeling(BIM) has become a hot topic in the construction industry such as quantity calculation, interference check, process management, and construction cost management. It is also trying to convert the existing 2D design to 3D design and introduce the BIM in various fields, thus, many new deliverable are being presented but there are many issues due to the lack of standard guides on the preparation and delivery criteria for such new deliverable and how to utilize performance data. Therefore, In order to develop the electronic delivery process, we analyzed the process related to the delivery of BIM digital models presented in domestic and international BIM guidelines and the delivery of products from the Korea National Railway. The analysis focused on the list of achievements, delivery process, quality review standards, and the utilization code system of the Korea National Railway through BIM guidelines and the National Railroad Service's business procedures. Based on these analysis results, it presents a plan to construct an functional module of electronic delivery.

• Journal of The Korean Society of Agricultural Engineers
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• v.61 no.1
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• pp.9-20
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• 2019

The primary objective of this study was to analyze the delivery ratio using Hydrological Simulation Program - Fortran (HSPF) in Okdong-cheon watershed. Model parameters related to hydrology and water quality were calibrated and validated by comparing model predictions with the 8-day interval filed data collected for ten years from the Korea Ministry of Environment. The results indicated that hydrology and water quality parameters appeared to be reasonably comparable to the field data. The pollutant delivery loads of the watershed in 2015 were simulated using the HSPF model. The delivery ratios of each subwatershed were also estimated by the simple ratio calculation of pollutant discharge load and pollutant delivery load. Coefficients of the regression equation between the delivery ratio and specific discharge were also computed using the delivery ratio. Based on the results, multiple regression analysis was performed using the discharge and the physical characteristics of the subwatershed such as the area. The equation of delivery ratio derived in this study is only for the Okdong-cheon watershed, so the larger studies are needed to apply the findings to other watersheds.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.45 no.4
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• pp.79-85
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• 2022

Various non-face-to-face services are being activated due to the influence of the Corona 19 virus around the world. However, unlike the rapid development of delivery services, social awareness of delivery services is causing many problems. Therefore, in this study, we analyze the quality attributes of delivery services from the consumer's point of view, and based on the results, we try to derive a direction for service improvement. In this study, quality factors were established through interviews and surveys with actual consumers, and quality attributes were classified through the Kano model and Timko's customer satisfaction coefficient. "Attractive" is ('Ease of ordering, Accurate delivery to the designated place'), "One Dimensional" is ('Variety of payment methods, Accurate delivery on time, Accurate delivery of ordered food, Degree of non-deformation of packaging conditions, etc., Convenience of use time'), "Must be" is ('Kindness of the delivery person'), "Reverse" is ('provision of services, service response to order discrepancies'). This study has academic significance in that it compensated for the disadvantage of not being able to interpret the mathematical meaning of the Kano model with Teamco's customer satisfaction coefficient. It also has practical implications in that it provides an indirect clue to future improvement directions.

• Safety and Health at Work
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• v.14 no.2
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• pp.207-214
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• 2023

Background: Occupational safety issues related to food delivery riders emerge with evidence of an increase in associated traffic accidents and injuries along with the rapid growth of the online food delivery business. This paper focuses on food delivery riders' job stress and investigates its relationships with both antecedents and risky riding outcomes. Method: Survey data were collected from 279 Taiwanese food delivery motorcycle riders and analyzed using hierarchical regression analysis. Results: The results show that job overload and time pressure positively impact riders' job stress, while self-efficacy slightly reduces job stress. Job stress positively leads to risky driving behavior and distraction. In addition, time pressure can strengthen the impact of job overload on job stress. Riders' risky riding attitude can also strengthen the impacts of job stress on risky riding behaviors and distraction. Conclusion: This paper advances the literature on online food delivery as well as the occupational safety improvement of food delivery riders. Specifically, this study provides insights into the job stress of food delivery motorcycle riders and the effects of job characteristics and risky behavioral consequences.

• Asia pacific journal of information systems
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• v.27 no.3
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• pp.156-175
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• 2017

The proposed conceptual framework is based in the relationships among knowledge of personal information security, trust on the personal information security policies of parcel delivery service companies, privacy concern, trust in and risk of parcel delivery services, and user satisfaction with parcel delivery services. Drawing upon both cognitive theory of emotion and cognitive emotion theory that complement each other, we propose a research model and examine the relationships between cognitive and emotional factors and the usage of parcel delivery services. The proposed model is validated using data from customers who have previously used parcel delivery services. The results show a significant relationship between the cognitive and affective factors and the usage of parcel delivery services. This study enhances our understanding of parcel delivery services based on the consumers' psychological processes and presents useful implications on the importance of privacy and security in these services.

• Journal of Distribution Science
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• v.22 no.9
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• pp.85-95
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• 2024

Purpose: Online food delivery platforms face challenges to operational efficiency due to increasing demand, a shortage of drivers, and the constraint of a one-order-at-a-time delivery policy. It is imperative to find solutions to address the inefficiencies in the food delivery industry. Bundling multiple orders can help resolve these issues, but it requires complex computations due to the exponential increase in possible order combinations. Research design, data and methodology: This study proposes three bundle delivery systems-static, dynamic, and hybrid-utilizing a machine learning-based classification model to reduce the number of order combinations for efficient bundle computation. The proposed systems are analyzed through simulations using market data from South Korea's online food delivery platforms. Results: Our findings indicate that implementing bundle systems extends service coverage to more customers, increases average driver earnings, and maintains lead times comparable to standalone deliveries. Additionally, the platform experiences higher service completion rates and increased profitability. Conclusions: This suggests that bundle systems are cost-effective and beneficial for all stakeholders in online food delivery platforms, effectively addressing the inefficiencies in the industry.

• International Journal of Highway Engineering
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• v.20 no.2
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• pp.45-55
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• 2018

PURPOSES : This study aims to survey and analyze the status of the design and completion documents output delivery system in public construction projects in order to assess the problems of the Ministry of Land, Infrastructure and Transport (MOLIT)'s electronic delivery system, with a focus on roads and rivers, and to offer improvement measures. METHODS : This study first surveys and analyzes laws and existing study trends with regard to the design and completion documents output delivery system in public construction projects. It further analyzes the status of the output delivery system in public construction projects, including roads, rivers, expressways, water resources, and railroads. In addition, a comparative analysis of the current electronic delivery system of MOLIT and Korea Expressway Corporation in the road field is conducted, and the problems and improvement measures for MOLIT's electronic output delivery system are presented. This study seeks to analyze problems and prepare improvement measures with regard to road and river public construction projects, as ordered by MOLIT's five regional offices. RESULTS : This study sought to prepare the electronic output delivery system with regard to public construction projects and present the analysis of its major problems and improvement measures in four categories: "the preparation of electronic design documents output delivery system improvement measures including inspection and delivery," "preparation of guidelines, systems, etc., concerning electronic design documents," "preparation of improvement measures for the construction project management system and electronic design document support tools", and "linking of MOLIT's electronic output delivery system with relevant agencies and the expansion thereof to local governments." CONCLUSIONS : This study analyzed the current status and problems of the MOLIT's electronic output delivery system in the field of road and river construction projects, and presented corresponding improvement measures. This study is expected to address the problems of the MOLIT's electronic output delivery system, and to provide the foundation for the preparation of an efficient electronic output delivery system for design and completion documents. In addition, this study is expected to boost the quality and utilization of the electronic design documents output, and to exchange, share, and link construction information among relevant agencies so as to prepare the foundation for sharing construction information.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.77
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• pp.1-22
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• 2018

Under CISG the places of delivery by the seller of the goods are: If the seller is not bound to deliver the goods at any other particular place and the contract of sale involves carriage of the goods, the seller has to hand the goods over to the first carrier for transmission to the buyer. However, if the contract does not involve carriage of the goods, he has to place them at the buyer's disposal at the place where, at the time of the conclusion of the contract, both the seller and the buyer knew that the goods were at, or were to be manufactured or produced. This rule applies when the contract relates to specific goods, or unidentified goods to be drawn from a specific stock or to be manufactured or produced. Finally, in ant other cases the seller has to place the goods at the buyer's disposal at the place where the seller had his place of business at the time of the conclusion of the contract. As to time of delivery, if a date is fixed by or determinable from the contract, the seller has to deliver the goods on that date. If a period for delivery is fixed by or determinable from the contract, he has to deliver the goods on any date within that period. In this way the seller chooses the specific date of delivery within that period, while circumstances indicate otherwise that the choice is to be made by the buyer. There no such date or period, the seller has to deliver the goods within a reasonable time after the conclusion of the contract. If the seller delivers the goods before such the date or period, the buyer is entitled to take delivery or refuse to take delivery. Under these backgrounds of provisions of CISG, this study first suggests the concepts of the handing over of the goods by the seller to the carrier and the placing them at the buyer's disposal. Then it goes further to looks into exactly where and when the delivery has to occur. In these context, this study more examines what happens if there is a breach of contract by the seller in connection with the delivery. That is, if the seller delivers non-conforming goods or at wrong place; what if there is a partial delivery or a premature delivery.