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Modeling the Effect of a Climate Extreme on Maize Production in the USA and Its Related Effects on Food Security in the Developing World (미국 Corn Belt 폭염이 개발도상국의 식량안보에 미치는 영향 평가)

  • Chung, Uran
    • Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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    • 2014.10a
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    • pp.1-24
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    • 2014
  • This study uses geo-spatial crop modeling to quantify the biophysical impact of weather extremes. More specifically, the study analyzes the weather extreme which affected maize production in the USA in 2012; it also estimates the effect of a similar weather extreme in 2050, using future climate scenarios. The secondary impact of the weather extreme on food security in the developing world is also assessed using trend analysis. Many studies have reported on the significant reduction in maize production in the USA due to the extreme weather event (combined heat wave and drought) that occurred in 2012. However, most of these studies focused on yield and did not assess the potential effect of weather extremes on food prices and security. The overall goal of this study was to use geo-spatial crop modeling and trend analysis to quantify the impact of weather extremes on both yield and, followed food security in the developing world. We used historical weather data for severe extreme events that have occurred in the USA. The data were obtained from the National Climatic Data Center (NCDC) of the National Oceanic and Atmospheric Administration (NOAA). In addition we used five climate scenarios: the baseline climate which is typical of the late 20th century (2000s) and four future climate scenarios which involve a combination of two emission scenarios (A1B and B1) and two global circulation models (CSIRO-Mk3.0 and MIROC 3.2). DSSAT 4.5 was combined with GRASS GIS for geo-spatial crop modeling. Simulated maize grain yield across all affected regions in the USA indicates that average grain yield across the USA Corn Belt would decrease by 29% when the weather extremes occur using the baseline climate. If the weather extreme were to occur under the A1B emission scenario in the 2050s, average grain yields would decrease by 38% and 57%, under the CSIRO-Mk3.0 and MIROC 3.2 global climate models, respectively. The weather extremes that occurred in the USA in 2012 resulted in a sharp increase in the world maize price. In addition, it likely played a role in the reduction in world maize consumption and trade in 2012/13, compared to 2011/12. The most vulnerable countries to the weather extremes are poor countries with high maize import dependency ratios including those countries in the Caribbean, northern Africa and western Asia. Other vulnerable countries include low-income countries with low import dependency ratios but which cannot afford highly-priced maize. The study also highlighted the pathways through which a weather extreme would affect food security, were it to occur in 2050 under climate change. Some of the policies which could help vulnerable countries counter the negative effects of weather extremes consist of social protection and safety net programs. Medium- to long-term adaptation strategies include increasing world food reserves to a level where they can be used to cover the production losses brought by weather extremes.

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Recent research activities on hybrid rocket in Japan

  • Harunori, Nagata
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2011.04a
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    • pp.1-2
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    • 2011
  • Hybrid rockets have lately attracted attention as a strong candidate of small, low cost, safe and reliable launch vehicles. A significant topic is that the first commercially sponsored space ship, SpaceShipOne vehicle chose a hybrid rocket. The main factors for the choice were safety of operation, system cost, quick turnaround, and thrust termination. In Japan, five universities including Hokkaido University and three private companies organized "Hybrid Rocket Research Group" from 1998 to 2002. Their main purpose was to downsize the cost and scale of rocket experiments. In 2002, UNISEC (University Space Engineering Consortium) and HASTIC (Hokkaido Aerospace Science and Technology Incubation Center) took over the educational and R&D rocket activities respectively and the research group dissolved. In 2008, JAXA/ISAS and eleven universities formed "Hybrid Rocket Research Working Group" as a subcommittee of the Steering Committee for Space Engineering in ISAS. Their goal is to demonstrate technical feasibility of lowcost and high frequency launches of nano/micro satellites into sun-synchronous orbits. Hybrid rockets use a combination of solid and liquid propellants. Usually the fuel is in a solid phase. A serious problem of hybrid rockets is the low regression rate of the solid fuel. In single port hybrids the low regression rate below 1 mm/s causes large L/D exceeding a hundred and small fuel loading ratio falling below 0.3. Multi-port hybrids are a typical solution to solve this problem. However, this solution is not the mainstream in Japan. Another approach is to use high regression rate fuels. For example, a fuel regression rate of 4 mm/s decreases L/D to around 10 and increases the loading ratio to around 0.75. Liquefying fuels such as paraffins are strong candidates for high regression fuels and subject of active research in Japan too. Nakagawa et al. in Tokai University employed EVA (Ethylene Vinyl Acetate) to modify viscosity of paraffin based fuels and investigated the effect of viscosity on regression rates. Wada et al. in Akita University employed LTP (Low melting ThermoPlastic) as another candidate of liquefying fuels and demonstrated high regression rates comparable to paraffin fuels. Hori et al. in JAXA/ISAS employed glycidylazide-poly(ethylene glycol) (GAP-PEG) copolymers as high regression rate fuels and modified the combustion characteristics by changing the PEG mixing ratio. Regression rate improvement by changing internal ballistics is another stream of research. The author proposed a new fuel configuration named "CAMUI" in 1998. CAMUI comes from an abbreviation of "cascaded multistage impinging-jet" meaning the distinctive flow field. A CAMUI type fuel grain consists of several cylindrical fuel blocks with two ports in axial direction. The port alignment shifts 90 degrees with each other to make jets out of ports impinge on the upstream end face of the downstream fuel block, resulting in intense heat transfer to the fuel. Yuasa et al. in Tokyo Metropolitan University employed swirling injection method and improved regression rates more than three times higher. However, regression rate distribution along the axis is not uniform due to the decay of the swirl strength. Aso et al. in Kyushu University employed multi-swirl injection to solve this problem. Combinations of swirling injection and paraffin based fuel have been tried and some results show very high regression rates exceeding ten times of conventional one. High fuel regression rates by new fuel, new internal ballistics, or combination of them require faster fuel-oxidizer mixing to maintain combustion efficiency. Nakagawa et al. succeeded to improve combustion efficiency of a paraffin-based fuel from 77% to 96% by a baffle plate. Another effective approach some researchers are trying is to use an aft-chamber to increase residence time. Better understanding of the new flow fields is necessary to reveal basic mechanisms of regression enhancement. Yuasa et al. visualized the combustion field in a swirling injection type motor. Nakagawa et al. observed boundary layer combustion of wax-based fuels. To understand detailed flow structures in swirling flow type hybrids, Sawada et al. (Tohoku Univ.), Teramoto et al. (Univ. of Tokyo), Shimada et al. (ISAS), and Tsuboi et al. (Kyushu Inst. Tech.) are trying to simulate the flow field numerically. Main challenges are turbulent reaction, stiffness due to low Mach number flow, fuel regression model, and other non-steady phenomena. Oshima et al. in Hokkaido University simulated CAMUI type flow fields and discussed correspondence relation between regression distribution of a burning surface and the vortex structure over the surface.

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Cancer Chemopreventive Effects of Ginsenoside $Rg_3,\;Rg_5,\;Rh_2$ and BST from Enzymatically Fermented Korean Ginseng Extract

  • Yun Taik-Koo
    • Proceedings of the Ginseng society Conference
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    • 2002.10a
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    • pp.35-46
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    • 2002
  • Panax ginseng C. A. Meyer has been one of the most highly recognized medicinal herbs in the Orient. Previous experiments have demonstrated that $Rg_3,\;and\;Rg_5$ statistically significantly decreased the incidence of benzo(a)pyrene-induced mouse lung tumor, $Rh_2$ showed tendency of decrease and $Rh_1$ showed no effect. It was, therefore, concluded that $Rg_3,\;Rg_5\;and\;Rh_2$ are active cancer chemopreventive components in red ginseng and they either singularly or synergistically act in the prevention of cancer. This study was undertaken to compare the cancer chemopreventive effects of $Rg_3,\;Rg_5\;and\;Rh_2$(purity: more than $60\%$) isolated from fermented ginseng extract and BST fermented ginseng with fortified ginsenoside $Rg_3\;and\;Rh_2$. The cancer chemopreventive effects were investigated in experimental groups treated with benzo(a)pyrene(BP) with ginsenoside $Rg_3,\;Rg_5\;Rh_2\;or\;BST$ at three doses of $50^{\circ}C/ml,\;100^{\circ}C/ml\;and\;200^{\circ}C/ml$ When mice given with $50^{\circ}C/ml$ concentration of ginsenoside $Rg_3$ combined with BP for 6 weeks after BP administration, $Rg_3\;showed\;60\%$ of lung tumor incidence, where as $100^{\circ}C/ml\;and\;200^{\circ}C/ml\;of\;Rg_3$ combined with BP groups had significant decrease of incidence $(40.0\%)$ respectively, with the inhibition rate being $35.5\%.$ While the tumor incidence was not decreased in the group treated with BP and 50 of $Rg_5,$ the incidence was $34.0\%\;and\;32.0\%$ in the group treated with BP and 100 and 200 of $Rg_5$, respectively. These incidences were significantly less than the group treated with BP alone, with the inhibition rate being $45.2\%\;and\;48.4\%,$ respectively. On the other hand, in the group treated with BP and 50 of ginsenoside $Rh_2,$ the tumor incidence was not decreased. However, the incidence was $40.0\%\;and\;38.8\%$ in the experimental treated with BP and 100 and 200 of $Rh_2,$ respectively, with the inhibition rate being $45.2\%\;and\;48.4\%,$ respectively. In addition, the incidence showed the tendency to decrease in the experimental group treated with BP and 50 of BST which contained $16.2\%\;of\;Rh_2,\;15.4\%\;of\;Rg_3\;and\;2.5%\;of\;Rg_5.$ The tumor incidence was $54.0\%$ in this group. In the group treated with 100 and 200 of EST, the incidence was $34.0\%\;and\;30.0\%,$ respectively, the incidences significantly being lower than the group treated with BP alone, with the inhibiting rate being $45.2\%\;and\;51.6\%,$ respectively. The results of this study strongly suggested that ginsenoside $Rg_3,\;Rg_5\;and\;Rh_2$ are the active components of red ginseng having a cancer chemopreventive activity and $Rg_5$ is the strongest cancer chempopreventive among them. On the other hand, the results demonstrating that the incidence of lung tumor was more markedly reduced by BST fermented ginseng with fortified ginsenoside $Rh_2\;or\;Rg_3$ compared to the single component alone, suggest that the combination of these components may remarkablely improve the cancer preventive effect

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A Statistical Study of the Foreign Bodies in the Food and Air Passages for past 4 years and 5 months (과거 4년 5개월간 본교실에서 취급한 식도 및 기도이물의 통계적 고찰)

  • 전지일;김성일;조현상;김정원;최태규;김진구;최병익;임현준;김영학
    • Proceedings of the KOR-BRONCHOESO Conference
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    • 1976.06a
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    • pp.87.4-88
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    • 1976
  • The statistcal study was done on 81 cases of the foreign bodies in the food passages (73 cases) and air passages (8 cases), who had visited the Dept. of Otolaryngology of Kyung Hee Medical Center and treated endoscopically, from Nov. 1971 to Mar 1976. The results were as follows, 1) The incidence of esophageal foreign bodies (73 cases) in order of frequency was coin (61 cases; 83.6%), bone (6 cases; 8.2%), food particles (3 cases; 4.1%), discs (2 cases), and other metals (l case). The incidence of foreign bodies in the air passages (8 cases) was food particles (3 cases; 37.5%), pointed metal (2 cases; 25%), plastic pencil cap (l case), plastic ring (1 case), and wood piece (1 case) in order. 2) In sex distribution, 51 cases (62.9%) were males and 30 cases (37.1%) were females, and the ratio between males and females was about 1.7 : 1.3. In the age incidence, 69 cases (82.5%) of all foreign bodies were under 5 years of age, and especially, coin cases were 59 cases (96.7%) and the highest was 8 years of age, lowest was 11 months of age. 7 cases (87.5%) of all airway foreign bodies were under 10 years of age. 4) The ratio between the food passages(73 cases) and the air passages (8 cases) was about 9 : 1. In the location of the foreign bodies of the food passages, 66 cases (90.4%) were in the first esophageal narrowing, 5 cases (6.9%) in the second narrowing, and 2 cases (2.7%) in the third narrowing. In the air passages, the frequent sites were trachea (5 cases; 62.5%), larynx (2 cases), and bronchus (1 case) in order. 5) In duration of lodgement, 63 cases (86. 3%) of esophageal foreign bodies were removed within 24 hours, and one case was removed within 16 days. The number of cases lodged within 24 hours were 4 cases (50%). in the air passages and one case was removed within 18 days. 6) In treatment, 37 cases (50.7%) of esophageal foreign bodies were extracted by modified upper esophagoscopy, 33 cases (42.5%) by esophagoscopy under the local anesthesia, 3 cases (4.1%) by esophagoscopy under the general anesthesia. 8 cases of the coin cases were passed into the stomach during the endoscopic examination. Laryngeal foreign bodies (2 cases; 25%) were extracted by laryngoscopy under the local anesthesia. 2 cases (40%) of tracheal foreign bodies by Bronchoscopy with tracheotomy under the local anesthesia, 3 cases (60%) by Bronchoscopy under the general anesthesia, and bronchial foreign body (1 case) by open thoracotomy under the general anesthesia, at the Dept. of Chest surgery.

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A statistical survey of the foreign bodies in the food and air passages (식도 및 기도이물의 통계적고찰)

  • 류항희;강병길;추연수;박재훈;김춘길;주양자
    • Proceedings of the KOR-BRONCHOESO Conference
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    • 1976.06a
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    • pp.88.1-88
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    • 1976
  • The authors have been performed a statistical survey for 228 cases with foreign bodies in the food and air passages who had visited the department of Otolaryngology, National Medical Center and removed endoscopically during the period of last 10 years from 1966 to 1975. The following results were obtained: 1. The total numbers of foreign bodies in the food and the air passages were 228 cases, and among of them 181 cases were foreign bodies in the food passage and 47 cases were foreign bodies in the air passage. The ratio between the food and the air passages was about 3.7 : 1. 2. The prevalent foreign bodies in the esophagus were coin, meat and food particles and bone in order of frequency. In air passage, bean and peanut were most prevalent foreign bodies and the next were metalic substances, fish bone in order of frequency. 3. In the age incidence, 65.4% of the esophageal foreign bodies and 67.6% of foreign bodies in the air passage were under 5 years of age especially coin, 92.9%. 4. In sex distribution, 99 cases were female, and the ratio between male and female was 1.3:1. There was no significant difference between male and female in the foreign bodies of the esophagus but the foreign bodies in the air passage were more prevalent in male as the ratio of 2.1:1. 5. The most prevalent site of lodgement in esophagus was first physiologic narrowing of the esophagus as the count of 83.8%. In foreign bodies of the air passage, bronchial foreign bodies were most frequent. And bronchial foreign bodies were more frequent in the right side as the ratio of 3.7:1. 6. In duration of lodgement, 56.0% of foreign bodies of the food passage were removed within 24 hours and almost of them were removed within 5 days. In foreign bodies in the air passage, only 32.4% were removed within 24 hours but 29.7% were removed within more than 1 week in the air passage. 7. Under the esophagoscope, granulation tissue were noted in the 5 cases of the foreign bodies in the esophagus due to foreign bodies. In foreign bodies of the air passage, complication were encountered in the 4 cases and also removed surgically and among of them, 2 patients were expired due to complications during post operative course.

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A hybrid algorithm for the synthesis of computer-generated holograms

  • Nguyen The Anh;An Jun Won;Choe Jae Gwang;Kim Nam
    • Proceedings of the Optical Society of Korea Conference
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    • 2003.07a
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    • pp.60-61
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    • 2003
  • A new approach to reduce the computation time of genetic algorithm (GA) for making binary phase holograms is described. Synthesized holograms having diffraction efficiency of 75.8% and uniformity of 5.8% are proven in computer simulation and experimentally demonstrated. Recently, computer-generated holograms (CGHs) having high diffraction efficiency and flexibility of design have been widely developed in many applications such as optical information processing, optical computing, optical interconnection, etc. Among proposed optimization methods, GA has become popular due to its capability of reaching nearly global. However, there exits a drawback to consider when we use the genetic algorithm. It is the large amount of computation time to construct desired holograms. One of the major reasons that the GA' s operation may be time intensive results from the expense of computing the cost function that must Fourier transform the parameters encoded on the hologram into the fitness value. In trying to remedy this drawback, Artificial Neural Network (ANN) has been put forward, allowing CGHs to be created easily and quickly (1), but the quality of reconstructed images is not high enough to use in applications of high preciseness. For that, we are in attempt to find a new approach of combiningthe good properties and performance of both the GA and ANN to make CGHs of high diffraction efficiency in a short time. The optimization of CGH using the genetic algorithm is merely a process of iteration, including selection, crossover, and mutation operators [2]. It is worth noting that the evaluation of the cost function with the aim of selecting better holograms plays an important role in the implementation of the GA. However, this evaluation process wastes much time for Fourier transforming the encoded parameters on the hologram into the value to be solved. Depending on the speed of computer, this process can even last up to ten minutes. It will be more effective if instead of merely generating random holograms in the initial process, a set of approximately desired holograms is employed. By doing so, the initial population will contain less trial holograms equivalent to the reduction of the computation time of GA's. Accordingly, a hybrid algorithm that utilizes a trained neural network to initiate the GA's procedure is proposed. Consequently, the initial population contains less random holograms and is compensated by approximately desired holograms. Figure 1 is the flowchart of the hybrid algorithm in comparison with the classical GA. The procedure of synthesizing a hologram on computer is divided into two steps. First the simulation of holograms based on ANN method [1] to acquire approximately desired holograms is carried. With a teaching data set of 9 characters obtained from the classical GA, the number of layer is 3, the number of hidden node is 100, learning rate is 0.3, and momentum is 0.5, the artificial neural network trained enables us to attain the approximately desired holograms, which are fairly good agreement with what we suggested in the theory. The second step, effect of several parameters on the operation of the hybrid algorithm is investigated. In principle, the operation of the hybrid algorithm and GA are the same except the modification of the initial step. Hence, the verified results in Ref [2] of the parameters such as the probability of crossover and mutation, the tournament size, and the crossover block size are remained unchanged, beside of the reduced population size. The reconstructed image of 76.4% diffraction efficiency and 5.4% uniformity is achieved when the population size is 30, the iteration number is 2000, the probability of crossover is 0.75, and the probability of mutation is 0.001. A comparison between the hybrid algorithm and GA in term of diffraction efficiency and computation time is also evaluated as shown in Fig. 2. With a 66.7% reduction in computation time and a 2% increase in diffraction efficiency compared to the GA method, the hybrid algorithm demonstrates its efficient performance. In the optical experiment, the phase holograms were displayed on a programmable phase modulator (model XGA). Figures 3 are pictures of diffracted patterns of the letter "0" from the holograms generated using the hybrid algorithm. Diffraction efficiency of 75.8% and uniformity of 5.8% are measured. We see that the simulation and experiment results are fairly good agreement with each other. In this paper, Genetic Algorithm and Neural Network have been successfully combined in designing CGHs. This method gives a significant reduction in computation time compared to the GA method while still allowing holograms of high diffraction efficiency and uniformity to be achieved. This work was supported by No.mOl-2001-000-00324-0 (2002)) from the Korea Science & Engineering Foundation.

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The Evaluation of Carbon Storage and Economic Value Assessment of Wetlands in the City of Seoul (서울시 습지지역의 탄소저장 및 경제적 가치 평가에 대한 연구)

  • Choi, Jiyoung;Oh Jongmin;Lee, Sangdon
    • Ecology and Resilient Infrastructure
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    • v.8 no.2
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    • pp.120-132
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    • 2021
  • The ecosystem and landscape conservation areas of Seoul were designated according to the Natural Environment Conservation Act and the Natural Environment Conservation Ordinance. With the adoption of the "Rapid Assessment of Wetland Ecosystem Service (RAWES)" approach and the "wetland ecosystem service" for the Ramsar Wetland City Accreditation at the 13th Meeting of the Conference of the Contracting Parties to the Ramsar Convention on Wetlands in 2018, the need for data evaluating wetland ecosystem services has become a necessity. Therefore, in this study, we selected five wetlands from the ecosystem and landscape conservation areas in Seoul, having high ecological conservation values, and evaluated their carbon sequestration and economic value assessment using the InVEST model, which is an ecosystem service evaluation technique. The evaluation results for carbon storage in each wetland are as follows: Tancheon Wetland: 3,674.62 Mg; Bamseom Island in the Hangang River: 1,511.57 Mg; Godeok-dong Wetland: 5,007.21 Mg; Amsa-dong Wetland: 7,108.47 Mg; and Yeouido Wetland: 290.27 Mg. Particularly, the Tancheon Wetland showed the lowest carbon sequestration of 1,130.37 Mg, as compared to the results acquired in 2013, of 4,804.99 Mg. When the average effective carbon rate of $16.06 (US) was applied to the decreased carbon sequestration value, a loss of $15,910.58(US) was calculated. Furthermore, if the average social cost of carbon ($204 (US)) is considered, which includes the impact of climate change on productivity and ecosystems, the total loss is equivalent to $202,101.97 (US). This study aims to examine the natural resource value of urban wetlands by evaluating selected major wetlands in Seoul. This study can be utilized as basic data to plan for the protection and management of the ecosystem and landscape conservation areas. Additionally, because wetland value assessment is considered essential, the results of this study can be used in future research to provide measures for evaluating ecosystem services in the Ramsar Wetland City Certification System. Moreover, this study can be utilized for selecting important wetlands as Ramsar sites, and to raise awareness about the significance of conserving urban wetlands, and for expanding international exchange among the Ramsar Wetland sites.

A Study on Systematizing Production and Access of the Public Institution's Conference Records -Focused on The Government in the Sunshine Act in USA - (공공기관의 회의록 생산·공개 제도화 연구 -미국의 회의공개법에 대한 분석을 중심으로-)

  • Byon, Ju-yon
    • The Korean Journal of Archival Studies
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    • no.17
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    • pp.203-245
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    • 2008
  • Although a few years have passed since the importance of the public record management became the subject, the management of the minutes which is produced from the deliberation and decision-making process of an important policy relatively was been neglected the while. When institutionally inspecting at present, the minutes production is based upon Record Management Law, and the minutes opening is based upon Freedom of Information Act. Although the minutes must be made out according to Record Management Law, it is not well operated. So, the minutes formally is made out and there was actually the important minutes excepted from the management object. Opening of the minutes made by Article 9 of Freedom of Information Act has the problem that be used as a basis of dividing unfairly into closed opening because the reason of the closed opening is vague. This study analyzes the problem of production and opening of the current minutes. It also considers Sunshine Act in USA and suggests a institutional ways for production and opening of Korean minutes. We can think of two institutional ways for production and opening of the minutes. One is making a separate law like Sunshine Act in USA. The other is revising the existing laws. In reality it's very difficult to make a new law for minute production and opening. Therefore, the purpose of this study is to suggest the way for revising Record Management Law and Freedom of Information Act that include minutes related regulations. The record must be fundamentally produced and opened for a nation and people as public records is the records of the nation and people as well as an authority which produced those records. If the minutes is produced and opened from a institutional change through the revision of Record Management Law and Freedom of Information Act, the minutes can not only help the responsible administration to realize but be utilized to important historical records as a basis data of an important policy decision-making.

A Proposal on the Improvement of Obstacle Limitation Surface and Aeronautical Study Method (장애물 제한표면과 항공학적 검토방법의 제도 개선에 관한 제언)

  • Kim, Hui-Yang;Jeon, Jong-Jin;Yu, Gwang-Eui
    • The Korean Journal of Air & Space Law and Policy
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    • v.34 no.1
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    • pp.159-201
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    • 2019
  • Along with Annex 14 Volume I establishment in 1951 and the set-up of restriction surface around the runway, aeronautical technique and navigation performance achieved dazzling growth, and the safety and precision of navigation greatly improved. However, restrictions on surrounding obstacles are still valid for safe operation of an aircraft. Standards and criteria for securing safety of aircraft operating around and on airport is stated in Annex 11 Air Traffic Services and Annex 14 Aerodrome etc. In particular, Annex 14 Volume I presents the criteria for limiting obstacles around an airport, such as natural obstacles such as trees, mountains and hills to prevent collisions between aircraft and ground obstacles, and artificial obstacles such as buildings and structures. On the other hand, Annex 14 Volume I, in the application of the obstacles limitation surfaces, apply the exception criteria, as it may not be possible to remove obstacles that violate the criteria if the aeronautical study determines that they do not impair the safety and regularity of aircraft operation. Aeronautical study has been applied and implemented in various countries including United States, Canada and Europe etc. accordingly, Korea established and amended some provisions of the Enforcement rules of the Aviation Act and established the Aeronautical study guidelines to approve exceptions. However, because ICAO does not provide specific guidelines on procedures and methods of Aeronautical study, countries conducting aeronautical study have established and applied their own procedures and methods. Reflecting this realistic situation, at the 12th World Navigation Conference and at the 38th General Assembly, the contracting States demanded a reexamination of the criteria for current obstacle limitation surfaces and methods of aeronautical study, and the ICAO dedicated a team of experts to prepare new standard. This study, in line with the movement of international change in obstacle limitation surface and aeronautical study, aims to compare and analyze current domestic and external standards on obstacle limitation and height limits, while looking at methods, procedure and systems for aeronautical study. In addition, expecting that aeronautical study will be used realistically and universally in assessing the impact of obstacles, we would recommend the institutional improvement of the aeronautical study along with the development of quantitative analysis methods using the navigation data in the current aeronautical study.

Seed Storage Behaviour of Three Species in Korean Native Dendranthema (국내 자생 산국속(Dendranthema) 3종의 종자 저장반응성 연구)

  • Chae, Inhwan;Kim, Hyekyung;Kim, Jinki;Jung, Young Ho;Lee, Hayan
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2019.04a
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    • pp.50-50
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    • 2019
  • 본 연구는 국내 자생 국화과의 산국속 3종을 대상으로 국립백두대간수목원 시드뱅크 내 장기저장 가능성을 확인하고자 수행되었다. 국화과 3종의 종자는 경북 봉화군 춘양면에서 2017년 11월에 채종한 후 선별하였다. 종자는 저장조건별($-20^{\circ}C$, 40%RH /$5^{\circ}C$, 30%RH /$15^{\circ}C$, 15%RH) 12주간 저장하여 2주단위로 발아실험을 실시하였다. 발아실험은 광12시간으로 25/15(12/12h)$^{\circ}C$ 변온조건으로 진행하였다. 종자는 10립 3반복으로 1% Agar배지에 치상하여 유근이 1mm 이상 출현한 것을 발아립으로 정의하였다. 평균발아율(GP)과 발아속도(MGT)를 조사하였다. 구절초를 조건별 2주 저장 후 평균발아율과 평균발아일수를 조사한 결과 $-20^{\circ}C/5^{\circ}C/15^{\circ}C$에서 각각 100%, $4.0{\pm}0.09$일 / $96.7{\pm}3.33%$, $3.7{\pm}0.08$일 / $93.3{\pm}3.33%$, $3.6{\pm}0.11$일로 조사 되었으며 12주 저장 후 100%, $4.1{\pm}0.27$일 / $96.7{\pm}3.33%$, $4.4{\pm}0.21$일 / $96.7{\pm}3.33%$, $3.7{\pm}0.13$일로 조사되어 저장 후 발아율의 감소를 보이지 않았으며 $5^{\circ}C$ 저장에서 평균발아일수가 길어지는 경향을 보였다. 포천구절초의 경우 $-20^{\circ}C/5^{\circ}C/15^{\circ}C$에서 각각 $96.7{\pm}3.33%$, $4.4{\pm}0.36$일 / 100%, $4.2{\pm}0.09$일 / $93.3{\pm}6.67%$, $4.1{\pm}0.22$일로 조사 되었으며 12주 저장 후 $96.7{\pm}3.33%$, $4.2{\pm}0.30$일 / $96.7{\pm}3.33%$, $4.2{\pm}0.15$일 / 100%, $4.0{\pm}0.09$일로 조사 되어 저장 전 후 차이를 확인 할 수 없었다. 한라구절초의 경우 $-20^{\circ}C/5^{\circ}C/15^{\circ}C$에서 각각 $93.3{\pm}3.33%$, $3.4{\pm}0.10$일 / $93.3{\pm}3.33%$, $3.7{\pm}0.08$일 / $93.3{\pm}6.67%$, $3.8{\pm}0.02$일로 조사 되었으며 12주 저장 후 $96.7{\pm}3.33%$, $4.0{\pm}0.21$일 / $96.7{\pm}3.33%$, $4.2{\pm}0.03$일 / $96.7{\pm}3.33%$, $3.8{\pm}0.09$일로 조사되어 발아율이 소폭 상승하는 경향을 보였다. 산국속 3종의 종자는 12주 저장 후 기간 및 저장조건에 따른 평균발아율과 발아속도에서 유의적인 차이를 나타내지 않았다. 이상의 결과로 산국속 3종 구절초, 포천구절초, 한라구절초의 종자는 저장기간 및 조건에 대해 민감한 반응을 보이지 않아 장기저장이 가능한 진정종자(Orthodox seed)로 판단된다.

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