• Title/Summary/Keyword: delivery cost

검색결과 838건 처리시간 0.022초

차세대 발사체용 연료선정에 관한 연구 (A Study on Fuel Selection for Next-Generation Launch Vehicles)

  • 김철웅;임병직;이기주;박재성
    • 한국추진공학회지
    • /
    • 제25권3호
    • /
    • pp.62-80
    • /
    • 2021
  • 차세대 추진기관에 대한 요구조건과 좋은 추진제의 조건을 정리하였다. 국내외에서 주로 관심을 받고 있는 연료인 케로신, 수소, 메탄의 특성과 효용성을 상호비교하였다. 비교 결과 메탄이 신뢰성, 비용, 재사용성, 유지보수, 친환경, 안전성, 수명, 기술적 난이도, 엔진 사이클 선택, 공통격벽, 무분해 조립 납품 등에서 다른 연료보다 더 유리한 것으로 평가되었다. 그리고 성능 면에서도 케로신보다 비추력이 높아서 발사체의 효율을 증가시킬 수 있다. 메탄은 친환경, 낮은 연소온도, 긴수명, 유지보수의 편의성을 가지고 있어서 재사용과 다목적 엔진 개발에 장점이 있다.

A Survey on 5G Enabled Multi-Access Edge Computing for Smart Cities: Issues and Future Prospects

  • Tufail, Ali;Namoun, Abdallah;Alrehaili, Ahmed;Ali, Arshad
    • International Journal of Computer Science & Network Security
    • /
    • 제21권6호
    • /
    • pp.107-118
    • /
    • 2021
  • The deployment of 5G is in full swing, with a significant yearly growth in the data traffic expected to reach 26% by the year and data consumption to reach 122 EB per month by 2022 [10]. In parallel, the idea of smart cities has been implemented by various governments and private organizations. One of the main objectives of 5G deployment is to help develop and realize smart cities. 5G can support the enhanced data delivery requirements and the mass connection requirements of a smart city environment. However, for specific high-demanding applications like tactile Internet, transportation, and augmented reality, the cloud-based 5G infrastructure cannot deliver the required quality of services. We suggest using multi-access edge computing (MEC) technology for smart cities' environments to provide the necessary support. In cloud computing, the dependency on a central server for computation and storage adds extra cost in terms of higher latency. We present a few scenarios to demonstrate how the MEC, with its distributed architecture and closer proximity to the end nodes can significantly improve the quality of services by reducing the latency. This paper has surveyed the existing work in MEC for 5G and highlights various challenges and opportunities. Moreover, we propose a unique framework based on the use of MEC for 5G in a smart city environment. This framework works at multiple levels, where each level has its own defined functionalities. The proposed framework uses the MEC and introduces edge-sub levels to keep the computing infrastructure much closer to the end nodes.

모바일 키 및 RCU에 기반한 공유공간 출입관리 시스템 개발 (Development ofn Sharing Space Access Management System based on Mobile Key and RCU(Room Control Unit))

  • 정상중
    • 융합신호처리학회논문지
    • /
    • 제21권4호
    • /
    • pp.202-208
    • /
    • 2020
  • 최근 코로나 19로 인해 비대면의 중요성이 강조되고 있으며, 공유공간의 이용 부분에 대하여도 확대되고 있다. 공유공간 출입관리에 언텍트 체크인 기술을 이용하면 대기시간을 감소시키며, 근무자의 효율을 최적화함에 따라서 운영비 절감효과가 발생한다. 본 논문에서는 모바일 키 및 RCU(Room Control Unit)에 기반한 공유공간 출입관리 시스템을 제안하여 모바일 키를 사용하여 시설에 대한 출입을 진행하고, RCU를 사용하여 시설에 대한 모니터링을 제안한다. 제안시스템은 공유 숙박, 임대 분야(레지던스, 분양형 호텔), 공유 오피스 등을 대상으로 특정 요일과 시간에 일회성 방문자가 있는 경우, 그에 맞는 비밀번호를 모바일 플랫폼 기반으로 전달함으로써 기존 비밀번호에 대한 노출 및 열쇠 전달 등의 불편함을 줄일 수 있는 현장적응형 시스템으로 지원한다. 제안 통합시스템의 동작을 시험하기 위해 사용자의 예약, 입실, 퇴실 등의 상태를 전반적으로 파악하기 위한 시나리오에 따라 테스트를 시행하였으며, 테스트의 신뢰성을 위해 성능지표를 설정하여 각 항목에 대한 100%의 성공률을 도출하였다.

Precision feeding and precision nutrition: a paradigm shift in broiler feed formulation?

  • Moss, Amy F.;Chrystal, Peter V.;Cadogan, David J.;Wilkinson, Stuart J.;Crowley, Tamsyn M.;Choct, Mingan
    • Animal Bioscience
    • /
    • 제34권3_spc호
    • /
    • pp.354-362
    • /
    • 2021
  • Broiler chickens grow rapidly, and their nutrient requirements change daily. However, broilers are fed three to five diet phases, meaning nutrients are under or oversupplied throughout production. Increasing diet phases improves production efficiency as there is less time in the production cycle that nutrients are in under or over-supply. Nevertheless, the process of administering four or more diets is costly and often impractical. New technologies are now available to blend feed to match the daily nutrient requirements of broilers. Thus, the aim of this review is to evaluate previous studies measuring the impact of increasing feed phases on nutrient utilisation and growth performance, and review recent studies taking this concept to the extreme; precision nutrition - feeding a new diet for each day of the production cycle. This review will also discuss how modern precision feeding technologies have been utilised and the potential that new technologies may bring to the poultry industry. The development of a precision nutrition regime which targets daily requirements by blending dietary components on farm is anticipated to improve the efficiency of production, reduce production cost and therefore improve sustainability of the industry. There is also potential for precision feeding technology along with precision nutrition strategies to deliver a plethora of other management and economic benefits. These include increased fluidity to cope with sudden environmental or market changes, and the ability to alter diets on a farm by farm level in a large, integrated operation. Thus, the future possibilities and practical implications for such technologies to generate a paradigm shift in feed formulation within the poultry industry to meet the rising demand for animal protein is also discussed.

질적 연구를 통한 대형병원 환자집중의 영향 요인 분석 : 대형병원 의료이용자와 관리자 관점에서 (A Study on Influencing Factor of Patient Leaning Phenomenon in Tertiary Hospitals through Qualitative Research : From the Perspective of Tertiary Hospital Users and Managers)

  • 이근정;엄혜은;고정애;박다혜
    • 한국병원경영학회지
    • /
    • 제26권1호
    • /
    • pp.55-70
    • /
    • 2021
  • Purpose: The purpose of this study was to examine the influencing factors of the patient leaning phenomenon in tertiary hospitals. Based on the results of this study, we intended to find implications for improving the problems of the delivery system imbalance in tertiary hospitals caused by patient leaning phenomenon. Methodology/Approach: Qualitative studies were conducted, using focus group interviews and in-depth interviews. The focus group interviews were conducted for 12 users of tertiary hospitals by 2 groups. And in-depth interviews were conducted for 6 tertiary hospital managers. This was considered to be the most effective approach to gather diverse and in-depth information about the influencing factor of patient leaning phenomenon in tertiary hospitals. Findings: In focus group interviews, the reason for choosing tertiary hospitals was the reliability of the hospital(physician, reputation, etc.). And the effect of the policy to strengthen coverage of National Health Insurance and private medical insurance was relatively small. In other words, we found that the individual's desire to receive medical services suitable for one's health status and disease condition was the biggest factor, rather than the cost and policy factors. Practical Implications: We suggested that the appropriate medical care provision should be strengthened according to the role and function of medical institutions. In addition, the education system needs to be reorganized to activate the referral program, expand community medical capabilities, and foster quality primary medical care.

건강보험 보장성 강화 및 지속가능성 제고 방안 연구 (A Study on Strengthening of Health Care Protection and Sustainability Plan)

  • 정용주
    • 한국콘텐츠학회논문지
    • /
    • 제21권4호
    • /
    • pp.96-110
    • /
    • 2021
  • 우리나라는 세계에서 가장 빠른 속도의 저출산·고령화와 저성장·저금리의 시대에 적응해야 하는 직면해 처해 있다. 저출산, 고령화로 인하여 건강보험 재정수입 요인은 감소하고 있으며, 국민의 건강에 관한 관심, 고비용 의료기술 및 의약품의 개발은 건강보험 재정 지출은 증가하게 있다. 본 연구에서는 건강보험의 보장성 강화와 재정의 안정화, 의료의 형평성에 대하여 검토해보고자 한다. 첫째, 국내의 정책보고서, 국내외 문헌, 선행연구를 통해 건강보험의 현황과 한계를 파악하였다, 둘째, 외국의 건강보험정책인 재정 안정화 대책에 대하여 구분하여 검토하였다. 이 연구를 근거로 건강보험의 보장성 강화와 재정 안정화를 통하여 지속 가능한 건강보험을 유지하기 위해서는 현재 건강보험의 재정수입 구조를 혁신하여야 할 것이다. 또한, 정부지원금의 확대, 새로운 조세 수입을 발굴하여야 할 것이다. 진료비 지불제도, 의료전달체계를 개편하여 재정을 절감하는 정책도 필요할 것이다.

지상군의 국지제공권 확보 가능성 연구 (A Study on the Possibility of Securing Command of the Air in Local War)

  • 이창인;정민섭;조상근;박상혁
    • 문화기술의 융합
    • /
    • 제8권4호
    • /
    • pp.173-179
    • /
    • 2022
  • 2014년 돈바스 분쟁과 2022년 우크라이나-러시아 전쟁 사례를 통해 제공권은 더 이상 공군에 의해서만 확보할 수 있는 것이 아님을 경험하고 있다. 기존의 공군이 수행하던 원거리 감시정찰과 타격은 드론과 미사일로 대체할 수 있으며 적의 공중공격은 판치르와 휴대형 대공미사일 같은 방공무기체계로 국지제공권을 장악하여 지상군의 자유로운 기동 작전을 수행할 수 있다. 즉, 지금처럼 공군과 해군이 원거리 작전을 통해 제공권을 장악하는 것이 훨씬 유리하며 지상군은 이들을 지원해주는 작전개념이 더욱 적절하다. 따라서 본 연구는 이러한 제공권 작전 수행체계에 대해 값비싼 전투기에 집중하기보다 비용 대 효과성 측면을 고려하여 방공무기체계, 드론, 미사일, 정밀유도 포탄 등을 병행 발전시켜 적의 공중공격에 신속히 역공할 수 있도록 제공권 작전 수행체계에 대한 시사점을 제공하는 것이다.

안전성 선호를 고려한 1인가구의 식품소비행태 분석 (Analysis of Food Consumption Behavior of Single-person Households in Consideration of Safety Preference)

  • 김지훈;임성수
    • 한국유기농업학회지
    • /
    • 제30권1호
    • /
    • pp.1-20
    • /
    • 2022
  • With the recent rapid increase in single-person households, food companies are releasing small packaging and small-capacity products regardless of product line such as beverages, fresh foods, and home snacks, and food consumption patterns are also changing. Meanwhile, as a series of accidents related to food safety occurred during cost-effective consumption pursuing price-performance, more consumers wanted to choose products that have been proven safe even with higher money due to food safety anxiety. Considering the concept of 'safety' of food, this study by using the 'ordered probit model' empirically investigated whether there is a difference in the degree of preference for safety in food consumption behavior between single-person and multi-person households. Summarizing the results, it was found that women rather than men, and elderly households among young and single-person households had a higher demand for food safety. The results of marginal effects considering food safety variables show that respondents with low frequency of delivery and take-out use are considering food safety more, and that single-person households are considering safety more than multi-person households. In the future, the population structure of Korea will continue to increase in single-person and elderly households, and women's economic activities will also continue to increase. Therefore, the growing home convenience food market needs marketing strategies to secure and emphasize food safety, such as sterilizing treatment technology for hygiene and safe container development from environmental hormones, and needs a lot of support and attention to meet changes in food culture trends and demographic structure.

SWOT Analysis and Expert Assessment of the Effectiveness of the Introduction of Healthcare Information Systems in Polyclinics in Aktobe, Kazakhstan

  • Lyudmila, Yermukhanova;Zhanar, Buribayeva;Indira, Abdikadirova;Anar, Tursynbekova;Meruyert, Kurganbekova
    • Journal of Preventive Medicine and Public Health
    • /
    • 제55권6호
    • /
    • pp.539-548
    • /
    • 2022
  • Objectives: The purpose of this study was to assess the organizational effectiveness of the introduction of a healthcare information system (electronic medical records and databases) in healthcare in Kazakhstan. Methods: The authors used a combination of 2 methods: expert assessment and strengths, weaknesses, opportunities, and threats (SWOT) analysis. SWOT analysis is a necessary element of research, constituting a mandatory preliminary stage both when drawing up strategic plans and for taking corrective measures in the future. The expert survey was conducted using 2 questionnaires. Results: The study involved 40 experts drawn from specialists in primary healthcare in Aktobe: 15 representatives of administrative and managerial personnel (chief doctors and their deputies, heads of medical statistics offices, organizational and methodological offices, and internal audit services) and 25 general practitioners. Conclusions: The following functional indicators of the medical and organizational effectiveness of the introduction of information systems in polyclinics were highlighted: first, improvement of administrative control, followed in descending order by registration and movement of medical documentation, statistical reporting and process results, and the cost of employees' working time. There has been no reduction in financial costs, namely in terms of the costs of copying, delivery of information in paper form, technical equipment, and paper.

Energy Efficient Cluster Head Selection and Routing Algorithm using Hybrid Firefly Glow-Worm Swarm Optimization in WSN

  • Bharathiraja S;Selvamuthukumaran S;Balaji V
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • 제17권8호
    • /
    • pp.2140-2156
    • /
    • 2023
  • The Wireless Sensor Network (WSN), is constructed out of teeny-tiny sensor nodes that are very low-cost, have a low impact on the environment in terms of the amount of power they consume, and are able to successfully transmit data to the base station. The primary challenges that are presented by WSN are those that are posed by the distance between nodes, the amount of energy that is consumed, and the delay in time. The sensor node's source of power supply is a battery, and this particular battery is not capable of being recharged. In this scenario, the amount of energy that is consumed rises in direct proportion to the distance that separates the nodes. Here, we present a Hybrid Firefly Glow-Worm Swarm Optimization (HF-GSO) guided routing strategy for preserving WSNs' low power footprint. An efficient fitness function based on firefly optimization is used to select the Cluster Head (CH) in this procedure. It aids in minimising power consumption and the occurrence of dead sensor nodes. After a cluster head (CH) has been chosen, the Glow-Worm Swarm Optimization (GSO) algorithm is used to figure out the best path for sending data to the sink node. Power consumption, throughput, packet delivery ratio, and network lifetime are just some of the metrics measured and compared between the proposed method and methods that are conceptually similar to those already in use. Simulation results showed that the proposed method significantly reduced energy consumption compared to the state-of-the-art methods, while simultaneously increasing the number of functioning sensor nodes by 2.4%. Proposed method produces superior outcomes compared to alternative optimization-based methods.