• 제목/요약/키워드: Supply and demand imbalance

검색결과 110건 처리시간 0.027초

세계(世界) Critical materials 관리(管理)를 위한 전략(戰略) (Strategy of Critical Materials Management in the World)

  • 김유정
    • 자원리싸이클링
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    • 제22권5호
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    • pp.3-12
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    • 2013
  • 수요확대가 전망되고 공급구조가 경직된 금속자원은 각국의 산업구조 및 자원확보 역량에 따라 리스크 관리가 필요하다. 이를 위해 금속자원의 위기성 평가가 다양화되고 있는데, 주로 희토류 등 희유금속이 위기물질 혹은 중요물질(Critical materials, Critical metal, Critical raw materials)로 선정되고 있다. 본 연구에서는 기술변화 및 수급불균형 등을 고려한 위기물질 선정체제 및 관리현황에 대해 살펴보고자 한다. 유럽, 미국 등은 신재생에너지 보급 확대에 따른 원재료 리스크를 평가하고 있으며, 일본은 자국 내 성장동력산업을 중심으로 핵심 원재료를 파악하고 있다. 영국은 자원채굴에 따른 환경부하를 고려하여 광종별 위기성을 평가하였다. 그리고 이러한 위기물질들의 가격시그널의 미약성, 비탄력적 공급구조, 기술변화에 민감한 수요변동성 등의 특징을 분석하였다.

포아송 회귀분석을 이용한 해운선사의 블랭크 세일링 영향 분석 연구 (A study on the impact analysis of blank sailing in the shipping industry using poisson regression analysis)

  • 류원형;최봉근;김정훈;박신우;남형식
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2023년도 추계학술대회
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    • pp.120-121
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    • 2023
  • 최근에 해운산업의 수요와 공급이 지속적으로 일치하지 않으면서 불균형 현상이 이어지고 있다. 이에 따라 해운선사들은 선박의 공급량을 조절하기 위해 블랭크 세일링을 실시하며 수요와 공급의 균형을 맞추고 있다. 블랭크 세일링은 화물 운송을 지연시키는 부정적인 연쇄효과를 발생시키기 때문에 본 연구에서는 포아송 회귀분석을 이용하여

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시스템 다이내믹스를 활용한 지역별 국내 의사인력 수요에 대한 추계모델 개발 (Development of a Demand Model for Physician Workforce Projection on Regional Inequity Problem in Korea Using System Dynamics)

  • 이경민;유기봉
    • 보건행정학회지
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    • 제32권1호
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    • pp.73-93
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    • 2022
  • Background: Appropriate physician workforce projection through reasonable discussions and decisions with a broad view on supply and demand of the workforce, thus, is very important for high-quality healthcare services. The study expects to provide preliminary research data on the workforce diagnosis standard model for Korean physician workforce policy decision through more flexible and objective physician workforce projection in reflection of diverse changes in healthcare policy and sociodemographic environments. Methods: A low flow rate through the causal map was developed, and an objective workforce demand projection from 2019 to 2040 was conducted. In addition, projections by scenarios under various situations were conducted with the low flow rate developed in the study. Lastly, the demand projection of the physician workforce by region of 17 cities and provinces was conducted. Results: First, demand of physicians in 2019 was 110,665, 113,450 in 2020, 129,496 in 2025, 146,837 in 2030, 163,719 in 2035, and 179,288 in 2040. Second, the scenario for the retirement of baby boomers led to a decrease in the growth rate due to time delay. Third, Seoul and Gyeonggi-do account for a high percentage of demand, a very high upward trend was identified in Gyeonggi-do, and as a result, the projection showed that the demand of the physician workforce in Gyeonggi-do would worsen over time. Conclusion: This study is meaningful in that rational and collective physician workforce supply and demand and its imbalance in workforce distribution were verified through various projections by scenarios and regions of Korea with System Dynamics.

수요자 중심의 정보보호 전문 인력 양성을 위한 교육과정 설계 (Designing demand side education of information security professionals)

  • 이종락
    • 디지털산업정보학회논문지
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    • 제9권3호
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    • pp.99-106
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    • 2013
  • There has been a lot of growth more than 10% in the information security industry. In accordance with the industrial growth, it increased needs for the information security manpower development as a national problem. But there is an imbalance between demand and supply of the information security manpower in terms of the quantity and quality. It is mainly caused by the curriculum of the information security is made considering for suppliers not for demanders. As a resolution to solve this problem, we suggest the curriculum of information security for vocational education and training. As the information security area is wide in view of required knowledge and technology, we design the curriculum by selecting major occupation type from the information security manpower distribution and products and then by investigating the job description using NCS(National Competency Standard). And we compared the curriculum to that of two or three year diploma courses in Korea.

독립운전 모드의 마이크로그리드에서 EDLC와 BESS의 주파수 협조제어전략 설계 (Design of Coordinated Frequency Control Strategy applied to EDLC and BESSs for Microgrid in the Islanded Mode)

  • 유형준;김학만
    • 전기학회논문지
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    • 제63권6호
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    • pp.820-827
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    • 2014
  • Since a microgrid has renewable energy sources, imbalance between power supply and power demand occurs in the islanded mode. In order to solve the imbalance, several energy storage systems (ESSs) such as bettary energy storage system (BESS), EDLC (electric double layer capacitor), flywheel, and SMES (superconducting magnetic energy storage) are generally used. Especially, their electrical characteristics are different. For efficient use of them, a coordinated control scheme is required. In this paper, a coordinated control scheme for using a Lead-acid BESS, a Lithium BESS, and a EDLC is designed to efficient frequency control for a microgrid in the islanded mode. The coordinated frequency control strategy is designed based on their electrical characteristics. The feasibility of the proposed coordinated frequency control strategy is verified through the simulation.

Projections of Demand for Cardiovascular Surgery and Supply of Surgeons

  • Lee, Jung Jeung;Park, Nam Hee;Lee, Kun Sei;Chee, Hyun Keun;Sim, Sung Bo;Kim, Myo Jeong;Choi, Ji Suk;Kim, Myunghwa;Park, Choon Seon
    • Journal of Chest Surgery
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    • 제49권sup1호
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    • pp.37-43
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    • 2016
  • Background: While demand for cardiovascular surgery is expected to increase gradually along with the rapid increase in cardiovascular diseases with respect to the aging population, the supply of thoracic and cardiovascular surgeons has been continuously decreasing over the past 10 years. Consequently, this study aims to achieve guidance in establishing health care policy by analyzing the supply and demand for cardiovascular surgeries in the medical service area of Korea. Methods: After investigating the actual number of cardiovascular surgeries performed using the National Health Insurance claim data of the Health Insurance Review and Assessment Service, as well as drawing from national statistics concerning the elderly population aged 65 and over, this study estimated the number of future cardiovascular surgeries by using a cell-based model. To be able to analyze the supply and demand of surgeons, the recent status of new surgeons specializing in thoracic and cardiovascular surgeries and the ratio of their subspecialties in cardiovascular surgeries were investigated. Then, while taking three different scenarios into account, the number of cardiovascular surgeons expected be working in 5-year periods was projected. Results: The number of cardiovascular surgeries, which was recorded at 10,581 cases in 2014, is predicted to increase consistently to reach a demand of 15,501 cases in 2040-an increase of 46.5%. There was a total of 245 cardiovascular surgeons at work in 2014. Looking at 5 year spans in the future, the number of surgeons expected to be supplied in 2040 is 184, to retire is 249, and expected to be working is 309-an increase of -24.9%, 1.6%, and 26.1%, respectively compared to those in 2014. This forecasts a demand-supply imbalance in every scenario. Conclusion: Cardiovascular surgeons are the most central resource in the medical service of highly specialized cardiovascular surgeries, and fostering the surgeons requires much time, effort, and resources; therefore, by analyzing the various factors affecting the supply of cardiovascular surgeons, an active intervention of policies can be prescribed for the areas that have failed to meet the appropriate market distributions.

병원 전 12-Lead ECG 측정을 통해 진단된 이형성 협심증 1례 (Variant angina diagnosed on pre-hospital 12-lead electrocardiogram: A case report)

  • 김지원;기은영
    • 한국응급구조학회지
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    • 제25권1호
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    • pp.243-249
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    • 2021
  • A decrease in coronary blood flow leads to an imbalance between the supply of oxygen to the myocardium and its demand, and reversible or irreversible damage to the myocardium could occur depending on the severity of the resultant ischemia and the duration of the imbalance. This imbalance results in a cascade of ischemic reactions in the following order: metabolic abnormalities, diastolic dysfunction, systolic dysfunction, and electrocardiogram changes. Variant angina is caused by the closure of the coronary artery due to reversible coronary artery spasm, resulting in myocardial ischemia and subsequent chest pain as a clinical symptom. Variant angina may be observed as ST segment elevation in electrocardiogram measured when present in chest pain. However, 12-lead electrocardiogram performed after the patient's chest pain resolves does not help in the diagnosis. Since the duration of chest pain appears to be <15 minutes, it is important to perform the 12-lead electrocardiogram when clinical symptoms are present. If nitroglycerin is administered without performing 12-lead electrocardiogram by 119 pre-hospital paramedics, the chest pain would be resolved, making it impossible to identify changes in the ST segment. Before administration of nitroglycerin, changes in the ST segment must be recorded by performing 12-lead electrocardiogram.

최적화된 Gradient-Boost를 사용한 서울 자전거 데이터의 결정 요인 예측 (Predicting Determinants of Seoul-Bike Data Using Optimized Gradient-Boost)

  • 김차영;김윤
    • 문화기술의 융합
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    • 제8권6호
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    • pp.861-866
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    • 2022
  • 서울시에서는 공유 자전거 시스템, "따릉이"를 2015년부터 도입, 운영하여, 교통량 감축과 대기오염 해소를 위해 노력하고 있다. 하지만 공유 자전거 시스템, "따릉이"의 운영전략 미훕으로 인해 많은 문제가 발생하고 있어 이를 해결하고자 다양한 연구들이 제시되고 있다. 이들 연구의 대다수는 수요와 공급의 불균형을 해결하고자 하는 전략적 "자전거 배치"에 집중되어 있으며 또한 이들 중 다수가 날씨나 계절과 같은 특징을 그룹화함으로써 수요를 예측하고 있다. 그리고 이전에는 이들 예측방법이 주로 시계열 분석을 기반으로 하고 있었으나 최근에는 딥러닝/머신러닝으로 수요를 예측하는 연구들이 속속 등장하고 있다. 본 논문에서는 기존에 제시된 다양한 특징들을 기반으로 하면서, 새로운 특징을 발견하고 선택된 특징들의 중요도를 비교, 이를 순서화함으로써, 보다 정확한 수요 예측이 가능함을 보인다. 그리하여, 우리는 기존의 딥러닝/머신러닝 및 시계열 분석을 그대로 사용하면서 비교적 정확한 결정계수를 획득하고 이를 이용해 개선된 수요예측이 가능하도록 한다.

Creating and Using BIM waste energy map Study on Energy Management

  • 김혜미;홍원화
    • 한국GIS학회:학술대회논문집
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    • 한국GIS학회 2010년도 추계학술대회
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    • pp.291-291
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    • 2010
  • Emerging global economic growth and increasing demand for energy supply and demand imbalance and the excessive use of fossil fuels existing the rapidly increasing greenhouse gas emissions and resource depletion of global energy crisis is deepening. Accordingly, improvement of living conditions around and through the natural ecological preservation and the need for a comfortable life for the meeting the importance of energy management and consumption are emerging. Many in the field of architecture for energy-saving measures and conducts research and analysis from the early stages to verify the energy performance of BIM (Building Information Model) technology development and commercialization through the building's energy performance to an objective technology forecasts Analysis of the existing building energy performance in waste management also possible that "BIM-based green building process, the possibility of" suggested. In this study, BIM through the analysis of information using the structures for the management of waste, energy and physical data collected by Mapping it can effectively plan resources for recycling were analyzed.

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경제지표가 컨테이너 운임에 미치는 영향에 관한 연구 (A study on the effect of economic indicators on container freight rates)

  • 하영규
    • 무역학회지
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    • 제47권1호
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    • pp.13-24
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    • 2022
  • This study was conducted because the global economic downturn caused by COVID-19 caused a surge in logistics costs and it was no longer possible to predict logistics costs using existing methods. For this study, we made the assumption that economic indicators affect logistics cost. Chapter 2 examines the current status of the liner market and factors affecting logistics costs. Based on this, Chapter 3 collects independent and dependent variables to determine the analysis model. As the independent variable, economic indicators of major countries constituting the SCFI were selected, and the dependent variables were the SCFI Europe Index and the SCFI USA Index. In Chapter 4, a panel analysis was conducted based on this, and it was confirmed that major economic indicators had a negative (-) effect on SCFI. This is contrary to the existing research results, which can be attributed to the special situation caused by COVID-19 and the imbalance of demand and supply by region. The results of this study are meaningful in that they can predict long-term logistics cost volatility without analyzing supply and demand, and can be applied to other studies as well.