• Title/Summary/Keyword: Power System

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Noise-robust electrocardiogram R-peak detection with adaptive filter and variable threshold (적응형 필터와 가변 임계값을 적용하여 잡음에 강인한 심전도 R-피크 검출)

  • Rahman, MD Saifur;Choi, Chul-Hyung;Kim, Si-Kyung;Park, In-Deok;Kim, Young-Pil
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.12
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    • pp.126-134
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    • 2017
  • There have been numerous studies on extracting the R-peak from electrocardiogram (ECG) signals. However, most of the detection methods are complicated to implement in a real-time portable electrocardiograph device and have the disadvantage of requiring a large amount of calculations. R-peak detection requires pre-processing and post-processing related to baseline drift and the removal of noise from the commercial power supply for ECG data. An adaptive filter technique is widely used for R-peak detection, but the R-peak value cannot be detected when the input is lower than a threshold value. Moreover, there is a problem in detecting the P-peak and T-peak values due to the derivation of an erroneous threshold value as a result of noise. We propose a robust R-peak detection algorithm with low complexity and simple computation to solve these problems. The proposed scheme removes the baseline drift in ECG signals using an adaptive filter to solve the problems involved in threshold extraction. We also propose a technique to extract the appropriate threshold value automatically using the minimum and maximum values of the filtered ECG signal. To detect the R-peak from the ECG signal, we propose a threshold neighborhood search technique. Through experiments, we confirmed the improvement of the R-peak detection accuracy of the proposed method and achieved a detection speed that is suitable for a mobile system by reducing the amount of calculation. The experimental results show that the heart rate detection accuracy and sensitivity were very high (about 100%).

EEG based Cognitive Load Measurement for e-learning Application (이러닝 적용을 위한 뇌파기반 인지부하 측정)

  • Kim, Jun;Song, Ki-Sang
    • Korean Journal of Cognitive Science
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    • v.20 no.2
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    • pp.125-154
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    • 2009
  • This paper describes the possibility of human physiological data, especially brain-wave activity, to detect cognitive overload, a phenomenon that may occur while learner uses an e-learning system. If it is found that cognitive overload to be detectable, providing appropriate feedback to learners may be possible. To illustrate the possibility, while engaging in cognitive activities, cognitive load levels were measured by EEG (electroencephalogram) to seek detection of cognitive overload. The task given to learner was a computerized listening and recall test designed to measure working memory capacity, and the test had four progressively increasing degrees of difficulty. Eight male, right-handed, university students were asked to answer 4 sets of tests and each test took from 61 seconds to 198 seconds. A correction ratio was then calculated and EEG results analyzed. The correction ratio of listening and recall tests were 84.5%, 90.6%, 62.5% and 56.3% respectively, and the degree of difficulty had statistical significance. The data highlighted learner cognitive overload on test level of 3 and 4, the higher level tests. Second, the SEF-95% value was greater on test3 and 4 than on tests 1 and 2 indicating that tests 3 and 4 imposed greater cognitive load on participants. Third, the relative power of EEG gamma wave rapidly increased on the 3rd and $4^{th}$ test, and signals from channel F3, F4, C4, F7, and F8 showed statistically significance. These five channels are surrounding the brain's Broca area, and from a brain mapping analysis it was found that F8, right-half of the brain area, was activated relative to the degree of difficulty. Lastly, cross relation analysis showed greater increasing in synchronization at test3 and $4^{th}$ at test1 and 2. From these findings, it is possible to measure brain cognitive load level and cognitive over load via brain activity, which may provide atimely feedback scheme for e-learning systems.

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Limitations of National Responsibility and its Application on Marine Environmental Pollution beyond Borders -Focused on the Effects of China's Three Gorges Dam on the Marine Environment in the East China Sea- (국경을 넘는 해양환경오염에 대한 국가책임과 적용의 한계 -중국의 산샤댐 건설로 인한 동중국해 해양환경 영향을 중심으로-)

  • Yang, Hee Cheol
    • Ocean and Polar Research
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    • v.37 no.4
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    • pp.341-356
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    • 2015
  • A nation has a sovereign right to develop and use its natural resources according to its policies with regard to development and the relevant environment. A nation also has an obligation not to harm other countries or damage environments of neighboring countries as consequences of such actions of developments or use of natural resources. However, international precedents induce a nation to take additional actions not to cause more damages from the specific acts causing environmental damages beyond national borders, when such acts have economic and social importance. That is to say that there is a tendency to resolve such issues in a way to promote the balance between the mutual interests by allowing such actions to continue. A solution to China's Three Gorges Dam dilemma based on a soft law approach is more credible than relying on a good faith approach of national responsibilities and international legal proceedings since the construction and operation of the dam falls within the category of exercising national sovereign rights. If a large scale construction project such as the Three Gorges Dam or operation of a nuclear power plant causes or may cause environmental damage beyond the border of a nation engaged in such an undertaking, countries affected by this undertaking should jointly monitor the environmental effects in a spirit of cooperation rather than trying to stop the construction and should seek cooperative solutions of mutual understanding to establish measures to prevent further damages. If China's Three Gorges Dam construction and operation cause or contain the possibility of causing serious damages to marine environment, China cannot set aside its national responsibility to meet international obligations if China is aware of or knows about the damage that has occurred or may occur but fail to prevent, minimize, reverse or eliminate additional chances of such damages, or fails to put in place measures in order to prevent the recurrence of such damages. However, Korea must be able to prove a causal relationship between the relevant actions and resulting damages if it is to raise objections to the construction or request certain damage-prevention actions against crucial adverse effects on the marine environment out of respect for China's right to develop resources and acts of use thereof. Therefore, it is essential to cumulate continuous monitoring and evaluations information pertaining to marine environmental changes and impacts or responses of affected waters as well as acquisition of scientific baseline data with observed changes in such baseline. As China has adopted a somewhat nonchalant attitude toward taking adequate actions to protect against marine pollution risks or adverse effects caused by the construction and operation of China's Three Gorges Dam, there is a need to persuade China to adopt a more active stance and become involved in the monitoring and co-investigation of the Yellow Sea in order to protect the marine environment. Moreover, there is a need to build a regular environmental monitoring system that includes the evaluation of environmental effects beyond borders. The Espoo Convention can serve as a mechanism to ease potential conflicts of national interest in the Northeast Asian waters where political and historical sensitivities are acute. Especially, the recent diplomatic policy advanced by Korea and China can be implemented as an important example of gentle cooperation as the policy tool of choice is based on regional cooperation or cooperation between different regions.

An Economic Factor Analysis of Air Pollutants Emission Using Index Decomposition Methods (대기오염 배출량 변화의 경제적 요인 분해)

  • Park, Dae Moon;Kim, Ki Heung
    • Environmental and Resource Economics Review
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    • v.14 no.1
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    • pp.167-199
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    • 2005
  • The following policy implications can be drawn from this study: 1) The Air Pollution Emission Amount Report published by the Ministry of Environment since 1991 classifies industries into 4 sectors, i. e., heating, manufacturing, transportation and power generation. Currently, the usability of report is very low and extra efforts should be given to refine the current statistics and to improve the industrial classification. 2) Big pollution industries are as follows - s7, s17 and s20. The current air pollution control policy for these sectors compared to other sectors are found to be inefficient. This finding should be noted in the implementation of future air pollution policy. 3) s10 and s17 are found to be a big polluting industrial sector and its pollution reduction effect is also significant. 4) The effect of emission coefficient (${\Delta}f$) has the biggest impact on the reduction of emission amount change and the effect of economic growth coefficient (${\Delta}y$) has the biggest impact on the increase of emission volume. The effect of production technology factor (${\Delta}D$) and the effect of the change of the final demand structure (${\Delta}u$) are insignificant in terms of the change of emission volume. 5) Further studies on emission estimation techniques on each industry sector and the economic analysis are required to promote effective enforcement of the total volume control system of air pollutants, the differential management of pollution causing industrial sectors and the integration of environment and economy. 6) Korea's economic growth in 1990 is not pollution-driven in terms of the Barry Commoner's hypothesis, even though the overall industrial structure and the demand structure are not environmentally friendly. It indicates that environmental policies for the improvement of air quality depend mainly on the government initiatives and systematic national level consideration of industrial structures and the development of green technologies are not fully incorporated.

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A Study about the Direction and Responsibility of the National Intelligence Agency to the Cyber Security Issues (사이버 안보에 대한 국가정보기구의 책무와 방향성에 대한 고찰)

  • Han, Hee-Won
    • Korean Security Journal
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    • no.39
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    • pp.319-353
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    • 2014
  • Cyber-based technologies are now ubiquitous around the glob and are emerging as an "instrument of power" in societies, and are becoming more available to a country's opponents, who may use it to attack, degrade, and disrupt communications and the flow of information. The globe-spanning range of cyberspace and no national borders will challenge legal systems and complicate a nation's ability to deter threats and respond to contingencies. Through cyberspace, competitive powers will target industry, academia, government, as well as the military in the air, land, maritime, and space domains of our nations. Enemies in cyberspace will include both states and non-states and will range from the unsophisticated amateur to highly trained professional hackers. In much the same way that airpower transformed the battlefield of World War II, cyberspace has fractured the physical barriers that shield a nation from attacks on its commerce and communication. Cyberthreats to the infrastructure and other assets are a growing concern to policymakers. In 2013 Cyberwarfare was, for the first time, considered a larger threat than Al Qaeda or terrorism, by many U.S. intelligence officials. The new United States military strategy makes explicit that a cyberattack is casus belli just as a traditional act of war. The Economist describes cyberspace as "the fifth domain of warfare and writes that China, Russia, Israel and North Korea. Iran are boasting of having the world's second-largest cyber-army. Entities posing a significant threat to the cybersecurity of critical infrastructure assets include cyberterrorists, cyberspies, cyberthieves, cyberwarriors, and cyberhacktivists. These malefactors may access cyber-based technologies in order to deny service, steal or manipulate data, or use a device to launch an attack against itself or another piece of equipment. However because the Internet offers near-total anonymity, it is difficult to discern the identity, the motives, and the location of an intruder. The scope and enormity of the threats are not just focused to private industry but also to the country's heavily networked critical infrastructure. There are many ongoing efforts in government and industry that focus on making computers, the Internet, and related technologies more secure. As the national intelligence institution's effort, cyber counter-intelligence is measures to identify, penetrate, or neutralize foreign operations that use cyber means as the primary tradecraft methodology, as well as foreign intelligence service collection efforts that use traditional methods to gauge cyber capabilities and intentions. However one of the hardest issues in cyber counterintelligence is the problem of "Attribution". Unlike conventional warfare, figuring out who is behind an attack can be very difficult, even though the Defense Secretary Leon Panetta has claimed that the United States has the capability to trace attacks back to their sources and hold the attackers "accountable". Considering all these cyber security problems, this paper examines closely cyber security issues through the lessons from that of U.S experience. For that purpose I review the arising cyber security issues considering changing global security environments in the 21st century and their implications to the reshaping the government system. For that purpose this study mainly deals with and emphasis the cyber security issues as one of the growing national security threats. This article also reviews what our intelligence and security Agencies should do among the transforming cyber space. At any rate, despite of all hot debates about the various legality and human rights issues derived from the cyber space and intelligence service activity, the national security should be secured. Therefore, this paper suggests that one of the most important and immediate step is to understanding the legal ideology of national security and national intelligence.

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Quantification of Caffeic Acid and Rosmarinic Acid and Antioxidant Activities of Hot-water Extracts from Leaves of Perilla frutescens (품종별 들깻잎 열수추출물의 caffeic acid와 rosmarinic acid의 함량 및 항산화력 비교)

  • Lee, Hyun-Sun;Lee, Hyun-Ah;Hong, Chung-Oui;Yang, Sung-Yong;Hong, Sung-Yu;Park, Sang-Yul;Lee, Ho-Jung;Lee, Kwang-Won
    • Korean Journal of Food Science and Technology
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    • v.41 no.3
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    • pp.302-306
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    • 2009
  • The principal objective of this investigation was to identify adequate species for the harvest of Perilla frutescens leaves, which provide profound antioxidant activities, and harbor abundant caffeic acid and rosmarinic acid. Namchun, Donggeul-2, Bora, Sae-bora and Neul-bora variants of the plant were assessed herein. In this study, we evaluated the antioxidant effects of these plants, and utilized an HPLC system to verify their caffeic acid and rosmarinic acid contents. Dried Perilla frutescens leaves were boiled at a temperature of $100^{\circ}C$ for three hours, and were lyopholized in a freezedryer. The extracts were then processed in order to confirm their antioxidant activities via 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical-scavenging activity assay, ferric-reducing antioxidant power (FRAP) assay, total flavonoid content and total polyphenol content assays. According to the observed antioxidant results of the five tested species of Perilla frutescens leaves, Bora and Donggeul-2 were shown to have more potent antioxidant activities than the other tested variants. The scavenge 50% of DPPH radical ($SC_50$ of DPPH) values were 241 ${\mu}g$ DM/mL in Donggeul-2 and 261 ${\mu}g$ DM/mL in Bora. Based on the results of the FRAP assay, the Bora variant showed a value of 796 mM $FeSO_4$ $7H_2O/g$ DM, and Donggeul-2 exhibited a value of 748 mM $FeSO_4$ $7H_2O/g$ DM, of which the total polyphenol contents were measured as 69.4 g GAE/kg DM and 61.8 g GAE/kg DM, respectively. Moreover, the Bora variant had the highest level of caffeic acid, and Donggeul-2 showed the highest rosmarinic acid content among the tested samples (0.87 mg/100 g wet base and 121 mg/100 g wet base, respectively). According to the results of this experiment, we selected two species, Bora and Donggeul-2, which were both verified to contain adequate and favorable antioxidant activities.

Impact of Sulfur Dioxide Impurity on Process Design of $CO_2$ Offshore Geological Storage: Evaluation of Physical Property Models and Optimization of Binary Parameter (이산화황 불순물이 이산화탄소 해양 지중저장 공정설계에 미치는 영향 평가: 상태량 모델의 비교 분석 및 이성분 매개변수 최적화)

  • Huh, Cheol;Kang, Seong-Gil;Cho, Mang-Ik
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.13 no.3
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    • pp.187-197
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    • 2010
  • Carbon dioxide Capture and Storage(CCS) is regarded as one of the most promising options to response climate change. CCS is a three-stage process consisting of the capture of carbon dioxide($CO_2$), the transport of $CO_2$ to a storage location, and the long term isolation of $CO_2$ from the atmosphere for the purpose of carbon emission mitigation. Up to now, process design for this $CO_2$ marine geological storage has been carried out mainly on pure $CO_2$. Unfortunately the $CO_2$ mixture captured from the power plants and steel making plants contains many impurities such as $N_2$, $O_2$, Ar, $H_2O$, $SO_2$, $H_2S$. A small amount of impurities can change the thermodynamic properties and then significantly affect the compression, purification, transport and injection processes. In order to design a reliable $CO_2$ marine geological storage system, it is necessary to analyze the impact of these impurities on the whole CCS process at initial design stage. The purpose of the present paper is to compare and analyse the relevant physical property models including BWRS, PR, PRBM, RKS and SRK equations of state, and NRTL-RK model which are crucial numerical process simulation tools. To evaluate the predictive accuracy of the equation of the state for $CO_2-SO_2$ mixture, we compared numerical calculation results with reference experimental data. In addition, optimum binary parameter to consider the interaction of $CO_2$ and $SO_2$ molecules was suggested based on the mean absolute percent error. In conclusion, we suggest the most reliable physical property model with optimized binary parameter in designing the $CO_2-SO_2$ mixture marine geological storage process.

Militarization and Weaponization of Outer Space in International Law

  • Kim, Han-Taek
    • The Korean Journal of Air & Space Law and Policy
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    • v.33 no.1
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    • pp.261-284
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    • 2018
  • The current international legal system does not provide a safeguard against the militarization and the weaponization of outer space. Although the term "peaceful use of outer space" in the 1967 Outer Space Treaty(OST) appears in official government statements or in multilateral space treaties, it is still without an authoritative definition in reviewing national practices. The ambiguous ban on weapons in Article IV of the OST allows countries to loophole on the deployment of other weapons other than nuclear weapons. Meanwhile "Draft Treaty on the Prevention of the Placement of Weapon in Outer Space and of the Threat or Use of Force against Outer Space Objects(PPWT)" to Conference on Disarmament (CD) commissioned by the UN General Assembly's Special Session jointly submitted by China and Russia in 2008 and later revised in 2014, attempting to define and prohibit the proliferation of weapons in outer space and provided definitions of prohibited weapons, are opposed by the US on the grounds that currently there is no arms race in outer space. Some experts support a hard law approach in which binding laws aimed at ultimately creating integrated and binding legal instruments in all aspects of the use of outer space should be adopted to regulate the military use of space. However as a temporary measure the soft law guidelines should be developed for the non liquiet, a situation where there is no applicable law. The soft law could be used to create support for the declaration of the treaties and to create international customary law. For example, the 1963 Declaration of Legal Principles Governing the Activities of States in the Exploration and Use of Outer Space that regulates the activities of the state in the exploration and use of the universe, and the 1992 Principles Relevant to the Use of Nuclear Power Sources in Outer Space will illustrated. While substantial portions of the former was codified later in the 1967 OST, the latter which, although written in somewhat mandatory terms, have been consistently complied with by states, have arguably become part of customary international law. On November 12, 1974, the General Assembly reaffirmed that the development of international law may be reflected inter alia, by declarations and resolutions of the General Assembly which may to that extent be taken into consideration by the International Court of Justice.

Effect of Dynamite Explosion Work Noise on Behavior of Israeli Carp, Cyprinus carpio in the Cage of Aquaculture (양식 향어의 행동에 미치는 발파작업 소음의 영향에 관한 연구)

  • SHIN Hyeon Ok
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.33 no.4
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    • pp.348-355
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    • 2000
  • This paper described the relationship between the behavior of the Israeli carp, Cyprinus carpio and the environmental noise level due to the dynamite explosion work. The experiment was conducted in the cage ($L10{\times}W4{\times}D4 m$) of aquaculture located at Chungjoo Lake, Chechon, in 1997. The fish trajectory was obtained by the telemetry system in which a pulsed ultrasonic pinger ($50 kHz, {\phi}16{\times}L70 mm$) attached to the fish was tracked three dimensionally, and the underwater noise levels were measured. The results of the study were as follows: 1. The underwater noise levels in the normal blasting measured at a distance of 400 m from the source of noise increased by $40 dB (re 1 {\mu}Pa)$ compared to the levels before explosion. The dominant frequency and the increased power spectrum level of the underwater noise by the explosion work were $75 to 100 Hz and 22.9 to 35.3 dB$, respectively. 2. The underwater noise levels in the test blasting measured at a distance of 350 m from the source of noise increased by average $49.5 dB (re 1 {\mu}Pa)$compared to the levels before explosion. 3. The swimming area of the fish was reduced with the time after explosion, and after more than one hour the fish represented the similar swimming area and behavior to the status of right before explosion. 4, The swimming depth layer of the fish was most of the case at the sea surface less than 1,0 m except during explosion or right after of it. But the fish swam downward when an external stimulus like the explosion noise was given to the fish. 5. The average swimming speeds of the fish before, during and after the works were about 1.2 times, 1.9 times and 1.0 times of the body length, respectively, and the speed of the fish with explosion was faster 1.6 times than the speed without of that. Consequently, the explosion noise levels measured by this study were sufficiently high to affect the fish, and the heavy shock by the explosion works could produce a considerable unfavorable effects to the fish.

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Present status and prospect for development of mushrooms in Korea

  • Jang, Kab-Yeul;Oh, Youn-Lee;Oh, Minji;Im, Ji-Hoon;Lee, Seul-Ki;Kong, Won-Sik
    • 한국균학회소식:학술대회논문집
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    • 2018.05a
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    • pp.27-27
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    • 2018
  • The production scale of mushroom cultivation in Korea is approximately 600 billion won, which is 1.6% of the Korean gross agricultural output. Annually, ca. 190,000 tons of mushrooms are harvested in Korea. Although the numbers of mushroom farms and cultivators are constantly decreasing, the total mushroom yields are increasing due to the large-scale cultivation facilities and automation. The recent expansion of the well-being trend causes increase in mushroom consumption in Korea: annual per capita consumption of mushroom was 3.9kg ('13) that is a little higher than European's average. Thus the exports of mushrooms, mainly Flammulina velutipes and Pleurotus ostreatus, have been increased since the middle of 2000s. Recently, however, it is slightly reduced. However, Vietnam, Hong Kong, the United States, the Netherlands and continued to export, and the country has increased recently been exported to Australia, Canada, Southeast Asia and so on. Canned foods of Agaricus bisporus was the first exports of the Korean mushroom industry. This business has reached the peak of the sale in 1977-1978. As Korea initiated trade with China in 1980, the international prices of mushrooms were sharply fall that led to shrink the domestic markets. According to the high demand to develop new items to substitute for A. bisporus, oyster mushroom (Pleurotus ostreatus) was received the attention since it seems to suit the taste of Korean consumers. Although log cultivation technique was developed in the early 1970s for oyster mushroom, this method requires a great deal of labor. Thus we developed shelf cultivation technique which is easier to manage and allows the mass production. In this technique, the growing shelf is manly made from fermented rice straw, that is the unique P. ostreatus medium in the world, was used only in South Korea. After then, the use of cotton wastes as an additional material of medium, the productivity. Currently it is developing a standard cultivation techniques and environmental control system that can stably produce mushrooms throughout the year. The increase of oyster mushroom production may activate the domestic market and contribute to the industrial development. In addition, oyster mushroom production technology has a role in forming the basis of the development of bottle cultivation. Developed mushroom cultivation technology using bottles made possible the mass production. In particular, bottle cultivation method using a liquid spawn can be an opportunity to export the F.velutipes and P.eryngii. In addition, the white varieties of F.velutipes were second developed in the world after Japan. We also developed the new A.bisporus cultivar "Sae-ah" that is easy to grown in Korea. To lead the mushroom industry, we will continue to develop the cultivars with an international competitive power and to improve the cultivation techniques. Mushroom research in Korea nowadays focuses on analysis of mushroom genetics in combination with development of new mushroom varieties, mushroom physiology and cultivation. Further studied are environmental factors for cultivation, disease control, development and utilization of mushroom substrate resources, post-harvest management and improvement of marketable traits. Finally, the RDA manages the collection, classification, identification and preservation of mushroom resources. To keep up with the increasing application of biotechnology in agricultural research the genome project of various mushrooms and the draft of the genetic map has just been completed. A broad range of future studies based on this project is anticipated. The mushroom industry in Korea continually grows and its productivity rapidly increases through the development of new mushrooms cultivars and automated plastic bottle cultivation. Consumption of medicinal mushrooms like Ganoderma lucidum and Phellinus linteus is also increasing strongly. Recently, business of edible and medicinal mushrooms was suffering under over-production and problems in distribution. Fortunately, expansion of the mushroom export helped ease the negative effects for the mushroom industry.

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