• Title/Summary/Keyword: Surplus power

Search Result 124, Processing Time 0.025 seconds

A Study on the Improvement Policy for Entering Telecommunication Business of Private Network Holders (자가망 사업자의 통신사업 진입에 따른 개선 방안)

  • 이동식;김기문
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.6 no.8
    • /
    • pp.1200-1205
    • /
    • 2002
  • Construction of Private networks is becoming easier due to the openness of telecommunication market, rapidly developing telecommunication technology. The size of existing private networks is becoming huge which resulted in surplus of capacity of the networks. These trends will generate a problem of efficient use of national telecommunication resources and which will be a factor for the structure of domestic telecommunication market which will have a big impact on the existing telecommunication carriers. Therefore, national policy of private network issues should be considered along with the national efforts for the information infrastructure, control of telecommunication market, fairness of competition, strength Power of national competition. In this paper it will be suggested that the efficient policy on the issue of domestic private network, by analyzing present situation, status quo, laws, regulation and procedure for domestic private networks and comparing it with those of U.S.A, Japan, EU.

Protection Ratio between ATSC Digital Broadcasting and WiBro Systems (ATSC 디지털 방송시스템과 WiBro 시스템 간 보호비 도출 연구)

  • Lee, Hui-Soo;Kang, Dong-Hoon;Park, Hyo-Bae;Oh, Wang-Rok
    • Journal of the Institute of Electronics Engineers of Korea TC
    • /
    • v.46 no.11
    • /
    • pp.61-65
    • /
    • 2009
  • It is crucial to derive a protection ratio between two communication systems before deploying a new communication systems in the vicinity of frequencies occupied by the existing communication systems. In this paper, computer simulation based protection ratio estimating scheme between ASTC (Advanced Television Systems Committee) digital broadcasting systems and WiBro (Wireless Broadband Internet) systems is proposed. The proposed scheme can be effectively exploited when a new communication services are deployed in the surplus frequency band after the expiration of the analog television broadcasting scheduled in 2012 in Korea.

A Study on the Efficient Improvement Policy of Private Network (자가전기통신설비의 효율적인 개선방안에 관한 연구)

  • 이동식;임종근;김기문
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 2002.11a
    • /
    • pp.63-69
    • /
    • 2002
  • Construction of Private networks is becoming easier due to the openness of telecommunication market, rapidly developing telecommunication technology. The size of existing private networks is becoming huge which resulted in surplus of capacity of the networks. These trends will generate a problem of efficient use of "national telecommunication resources" and which ill be a factor for the structure of domestic telecommunication market which will have a big impact on the existing telecommunication carriers. Therefore, national policy of private network issues should be considered along with the national efforts for the information infrastructure, control of telecommunication market, fairness of competition, strength power of national competition. In this paper it will be suggested that the efficient policy on the issue of domestic private network, by analyzing present situation, status quo, laws, regulation and procedure for domestic private networks and comparing it with those of U.S.A, Japan, EU.apan, EU.

  • PDF

Value Relevance of Accounting Information in KOSDAQ (코스닥시장에서 회계정보의 매매관련성에 관한 연구)

  • Yoon, Sung-Yong;Park, Jong-Hyuk;Lee, Ho-Seoub
    • Management & Information Systems Review
    • /
    • v.25
    • /
    • pp.203-222
    • /
    • 2008
  • This thesis examines whether accounting information-earnings and book values-has the value relevance in the KOSDAQ. The study is motivated by previous studies which have examined the value relevance of accounting information. Prior researches have focused on KSE(Korea Stock Exchange). But, prior researches have not examined the value relevance of accounting information in KOSDAQ. So, this study examined the value relevance of accounting information which is disclosed by firms on KOSDAQ and whether accounting information between firms on KOSDAQ and KSE has the discriminative value relevance, underlying the expectation that KOSDAQ firms will have higher future profitability than KSE firms. In other words, book-value multiples of KOSDAQ firms is higher than book-value multiples of KSE firms and earnings multiples of KOSDAQ firms is lower than earnings multiples of KSE firms. The value relevance of accounting information is examined by a valuation framework presented by Ohlson(1995), which expresses the stock-price as a function of both earnings and book values of equity. The results indicate that accounting information of KOSDAQ has significant explanatory power for stock price over the 2005-2007 period. KOSDAQ firm are divided by Venture firms and Small to Mid size firms. KOSDAQ Venture firms have the discriminative value relevance, compared with KSE firms. But, KOSDAQ Small to Mid size firms have not the discriminative value relevance, compared with KSE firms.

  • PDF

A Study of Load Matching on the Net-Zero Energy House (넷 제로에너지주택의 부하매칭에 관한 연구)

  • Kim, Beob-Jeon;Lim, Hee-Won;Kim, Deok-Sung;Shin, U-Cheul
    • Journal of the Korean Solar Energy Society
    • /
    • v.38 no.4
    • /
    • pp.55-66
    • /
    • 2018
  • nZEH (net-Zero Energy House) is defined as a self-sufficient energy building where the sum of energy output generated from new & renewable energy system and annual energy consumption is zero. The electricity generated by new & renewable energy system with the form of distributed generation is preferentially supplied to electrical demand, and surplus electricity is transmitted back to grid. Due to the recent expansion of houses with photovoltaic system and the nZEH mandatory by 2025, the rapid increase of distributed generation is expected. Which means, we must prepare for an electricity-power accident and stable electricity supply. Also electricity charges have to be reduce and the grid-connected should be operated efficiently. The introduction of ESS is suggested as a solution, so the analysis of the load matching and grid interaction is required to optimize ESS design. This study analyzed the load matching and grid interaction by expected consumption behavior using actual data measured in one-minute intervals. The experiment was conducted in three nZEH with photovoltaic system, called all-electric houses. LCF (Load Cover Factor), SCF (Supply Cover Factor) and $f_{grid}$ (Grid Interaction Index) were evaluated as an analysis indicator. As a result, LCF, SCF and $f_{grid}$ of A house were 0.25, 0.23 and 0.27 respectively; That of B house were 0.23, 0.23, 0.19, and that of C were 0.20, 0.19, 0.27 respectively.

Factors Affecting Profitability of General Hospitals Focused on Operating Margin (병원의 수익성 관련 요인 분석 - 의료수익의료이익율을 중심으로 -)

  • Park, Byung-Sang;Lee, Yong-Kyoon;Kim, Yoon-Shin
    • The Journal of the Korea Contents Association
    • /
    • v.9 no.6
    • /
    • pp.196-206
    • /
    • 2009
  • The profitability of a hospital refers to business administration results achieved through its medical care and other management activities during applicable fiscal year. This study focused on operating margin as a measurement index of hospital profitability, which is a genuine medical return obtained by subtracting medical expenses from medical profits achieved during business administration of hospital. Based on the index, this study could deduce certain factors on hospital profitability in terms of various indices affecting profitability. And based on those factors, this study sought to provide more useful reference materials which allow us to devise possible ways to improve hospital profitability. As a result, it was found that public hospitals attained lower profitability than private ones. To analyze profitability depending on each index, this study divided hospitals broadly into deficit group and surplus group. As a result, it was found that there were significant differences in hospital profitability between two groups depending upon relevant indices such as labor cost ratio, maintenance expense ratio, number of operations per medical specialist and medical instrument turnover. According to analysis on potential effects of relevant indices upon profitability, it was found that each index had its explanatory power ranging from 25% to 74.5% depending on given model.

Effect of Number of Shutdown on the Decrease of Performance in PEM Water Electrolysis (PEM 수전해에서 정지횟수가 성능 감소에 미치는 영향)

  • Cheunho Chu;Jongwon Yang;Ilchai Na;Yoonjin Park
    • Korean Chemical Engineering Research
    • /
    • v.61 no.2
    • /
    • pp.202-207
    • /
    • 2023
  • In the case of driving water electrolysis by receiving surplus electricity from solar and wind power generation, operation and stopping must be repeated according to weather fluctuations. When the PEMWE(Polymer Electrolyte Membrane Water Electrolysis) is driven and stopped, the PEM fuel cell is in the same state as the PEM fuel cell due to the residual hydrogen and oxygen, and the high potential of the water electrolysis formed during operation is highly likely to cause degradation of the electrode and membrane even during stopping. In this study, in order to check how much degradation of the electrode and membrane progresses during the repeated driving/shutdown process of PEM water electrolysis, the performance decrease was measured by changing the number of driving/shutdown for 144 hours. Changes in electrode catalyst active area, hydrogen permeability and fluorine emision rate of membranes were analyzed to measure changes in the properties of electrodes and polymer membranes. Overall, the PEMWE performance decreased as the number of stops increased. When stopped 5 times in 144 hours, the IrOx catalyst activity decreased by more than 30%, and the hydrogen permeability increased by 80%, confirming that both the electrode and the membrane were deteriorated.

Postmodern Animality and Spectrality: Ted Hughes's Wodwo and Crow

  • Park, Jung Pil
    • Journal of English Language & Literature
    • /
    • v.58 no.6
    • /
    • pp.1143-1165
    • /
    • 2012
  • Tinted with ontological concern, Ted Hughes passes through an existential climate, eventually confirms death( or nothingness) as the new foundation of his poetry, and explores the various paradoxical effects of nothingness. Nihilism, fraught with rather negative and traumatic themes such as death, melancholy, and despair can, however, generate being (even in multiple modes), animalistic vitality, and insubstantial specters. Among these new functions of nothingness animality and spectrality are the most notable in Hughes's poetry. A considerable number of animals and bioorganisms that Hughes introduces exhibit the enormous energy derived from the dignity of death, from subversive challenges against the established hierarchy, and from new and dynamic multifaceted sources of nothingness. In other words, Hughes's animals, yield surplus power beyond themselves, as if they are demi-gods; in short, they feature the sublime as unidentified terrifying effects of nothingness. In a sense, animality means allowing some level of violence without legal sanction. Hughes inaugurates this kind of all bigotry-eradicating violence and attempts to subvert higher beings such as humans and gods, and existing doctrines: thrushes rise up against the animal and human worlds; a rush of ghostly crabs at night press through the human world. Hughes also resists the highest being, God, employing the technique of rewriting God's theology. Dirty, anomalous crows attack, subvert, and dismember the delicate, indurate, and thorough system of logos. Hughes, of course, does not place the animals merely in lofty regard, aware of the ulterior deprivation of the sublime animality, the trace of existential negativity. Thus, a seemingly omnipotent crow can become a mere beggar guzzling ice cream from the garbage bin on the beach. In addition, the violent and dignified aspects of nothingness can be transformed to reveal the thin and trivial traits as unreliable specters. Dark, heavy, and terrible nullity lessens its own volume and mass, and exposes the airy waves of shadows or specters. However, owing to nullity's untraceable track, the scarcity and unfamiliarity of the phantoms inversely display their foreign gigantic effects such as fantasy and violence.

Economic analysis of Frequency Regulation Battery Energy Storage System for Czech combined heat & power plant (체코 열병합발전소 주파수조정용 배터리에너지저장장치 경제성 분석)

  • KIM, YuTack;Cha, DongMin;Jung, SooAn;Son, SangHak
    • Journal of Energy Engineering
    • /
    • v.29 no.2
    • /
    • pp.68-78
    • /
    • 2020
  • According to the new climate change agreement, technology development to reduce greenhouse gases is actively conducted worldwide, and research on energy efficiency improvement in the field of power generation and transmission and distribution is underway [1,2]. Economic analysis of the operation method of storing and supplying surplus electricity using energy storage devices, and using energy storage devices as a frequency adjustment reserve power in regional cogeneration plants has been reported as the most profitable operation method [3-7]. Therefore, this study conducted an economic analysis for the installation of energy storage devices in the combined heat and power plant in the Czech Republic. The most important factor in evaluating the economics of battery energy storage devices is the lifespan, and the warranty life is generally 10 to 15 years, based on charging and discharging once a day. For the simulation, the ratio of battery and PCS was designed as 1: 1 and 1: 2. In general, the primary frequency control is designed as 1: 4, but considering the characteristics of the cogeneration plant, it is set at a ratio of up to 1: 2, and the capacity is simulated at 1MW to 10MW and 2MWh to 20MWh according to each ratio. Therefore, life was evaluated based on the number of cycles per year. In the case of installing a battery energy storage system in a combined heat and power plant in the Czech Republic, the payback period of 3MW / 3MWh is more favorable than 5MW / 5MWh, considering the local infrastructure and power market. It is estimated to be about 3 years or 5 years from the simple payback period considering the estimated purchase price without subsidies. If you lower the purchase price by 50%, the purchase cost is an important part of the cost for the entire lifetime, so the payback period is about half as short. It can be, but it is impossible to secure profitability through the economy at the scale of 3MWh and 5MWh. If the price of the electricity market falls by 50%, the payback period will be three years longer in P1 mode and two years longer in P2 and P3 modes.

Clustering of Smart Meter Big Data Based on KNIME Analytic Platform (KNIME 분석 플랫폼 기반 스마트 미터 빅 데이터 클러스터링)

  • Kim, Yong-Gil;Moon, Kyung-Il
    • The Journal of the Institute of Internet, Broadcasting and Communication
    • /
    • v.20 no.2
    • /
    • pp.13-20
    • /
    • 2020
  • One of the major issues surrounding big data is the availability of massive time-based or telemetry data. Now, the appearance of low cost capture and storage devices has become possible to get very detailed time data to be used for further analysis. Thus, we can use these time data to get more knowledge about the underlying system or to predict future events with higher accuracy. In particular, it is very important to define custom tailored contract offers for many households and businesses having smart meter records and predict the future electricity usage to protect the electricity companies from power shortage or power surplus. It is required to identify a few groups with common electricity behavior to make it worth the creation of customized contract offers. This study suggests big data transformation as a side effect and clustering technique to understand the electricity usage pattern by using the open data related to smart meter and KNIME which is an open source platform for data analytics, providing a user-friendly graphical workbench for the entire analysis process. While the big data components are not open source, they are also available for a trial if required. After importing, cleaning and transforming the smart meter big data, it is possible to interpret each meter data in terms of electricity usage behavior through a dynamic time warping method.